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  • Question 1 - A 29-year-old man newly diagnosed with epilepsy visits his GP with complaints of...

    Correct

    • A 29-year-old man newly diagnosed with epilepsy visits his GP with complaints of fatigue. He has no significant medical history except for taking oral phenytoin and loratadine seasonally. He works as a construction site worker and has been experiencing a lot of stress at work due to the need to work extra shifts. During the consultation, he appears anxious and has a slim build. His blood test reveals macrocytic anaemia.

      What could be the probable reason for his symptoms and blood results?

      Your Answer: Side effect of phenytoin

      Explanation:

      The most probable reason for the patient’s fatigue and abnormal blood results is the side effect of phenytoin. Phenytoin is an antifolate medication that can lead to folate deficiency, resulting in macrocytic anaemia, which is evident in the patient’s blood test. Fatigue is a common symptom of anaemia, which the patient has reported.

      Although lack of sleep may contribute to the patient’s tiredness, it alone cannot cause macrocytic anaemia.

      Hypothyroidism can cause macrocytic anaemia and lethargy, but it is less likely to be the cause of the patient’s symptoms. The patient has no history of thyroid disorders, and his slim build and anxiety are more typical of hyperthyroidism.

      Loratadine is a second-generation antihistamine that does not usually cause drowsiness.

      Understanding Macrocytic Anaemia

      Macrocytic anaemia is a type of anaemia that can be classified into two categories: megaloblastic and normoblastic. Megaloblastic anaemia is caused by a deficiency in vitamin B12 or folate, which leads to the production of abnormally large red blood cells in the bone marrow. This type of anaemia can also be caused by certain medications, alcohol, liver disease, hypothyroidism, pregnancy, and myelodysplasia.

      On the other hand, normoblastic anaemia is caused by an increase in the number of immature red blood cells, known as reticulocytes, in the bone marrow. This can occur as a result of certain medications, such as methotrexate, or in response to other underlying medical conditions.

      It is important to identify the underlying cause of macrocytic anaemia in order to provide appropriate treatment. This may involve addressing any nutritional deficiencies, managing underlying medical conditions, or adjusting medications. With proper management, most cases of macrocytic anaemia can be successfully treated.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 2 - A 25-year-old male is experiencing abdominal pain and is undergoing an abdominal ultrasound...

    Incorrect

    • A 25-year-old male is experiencing abdominal pain and is undergoing an abdominal ultrasound scan. During the scan, the radiologist observes signs of splenic atrophy. What could be the probable cause of this condition?

      Your Answer: Sarcoidosis

      Correct Answer: Coeliac disease

      Explanation:

      In coeliac disease, the spleen may undergo atrophy and Howell-Jolly bodies may be observed in red blood cells. Histiocytosis X includes Letterer-Siwe disease, which involves the excessive growth of macrophages.

      The Anatomy and Function of the Spleen

      The spleen is an organ located in the left upper quadrant of the abdomen. Its size can vary depending on the amount of blood it contains, but the typical adult spleen is 12.5cm long and 7.5cm wide, with a weight of 150g. The spleen is almost entirely covered by peritoneum and is separated from the 9th, 10th, and 11th ribs by both diaphragm and pleural cavity. Its shape is influenced by the state of the colon and stomach, with gastric distension causing it to resemble an orange segment and colonic distension causing it to become more tetrahedral.

      The spleen has two folds of peritoneum that connect it to the posterior abdominal wall and stomach: the lienorenal ligament and gastrosplenic ligament. The lienorenal ligament contains the splenic vessels, while the short gastric and left gastroepiploic branches of the splenic artery pass through the layers of the gastrosplenic ligament. The spleen is in contact with the phrenicocolic ligament laterally.

      The spleen has two main functions: filtration and immunity. It filters abnormal blood cells and foreign bodies such as bacteria, and produces properdin and tuftsin, which help target fungi and bacteria for phagocytosis. The spleen also stores 40% of platelets, reutilizes iron, and stores monocytes. Disorders of the spleen include massive splenomegaly, myelofibrosis, chronic myeloid leukemia, visceral leishmaniasis, malaria, Gaucher’s syndrome, portal hypertension, lymphoproliferative disease, haemolytic anaemia, infection, infective endocarditis, sickle-cell, thalassaemia, and rheumatoid arthritis.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 3 - A 65-year-old man comes to the emergency department complaining of abdominal pain, lethargy,...

    Correct

    • A 65-year-old man comes to the emergency department complaining of abdominal pain, lethargy, and increased thirst for the past 5 days. He reports not having a bowel movement in 3 days. The patient is currently undergoing investigations for multiple myeloma.

      The emergency department physician suspects that the patient's symptoms are due to hypercalcemia related to his multiple myeloma. What is the primary mechanism behind this diagnosis?

      Your Answer: Increased osteoclast activity in response to cytokines released by the myeloma cells

      Explanation:

      The primary cause of hypercalcemia in multiple myeloma is increased osteoclast activity in response to cytokines released by the myeloma cells. This neoplasm of bone marrow plasma cells is most commonly seen in males aged 60-70 years old, which fits the demographic of the patient in this scenario. It is important to investigate patients presenting with hypercalcemia for an underlying diagnosis of multiple myeloma. Decreased osteoblast function, elevated PTH-rP levels, and impaired renal function are less contributing factors to hypercalcemia in myeloma compared to increased osteoclastic activity. Although impaired renal function is commonly seen in multiple myeloma, it is not stated whether this patient has decreased renal function.

      Understanding Multiple Myeloma: Features and Investigations

      Multiple myeloma is a type of cancer that affects the plasma cells in the bone marrow. It is most commonly found in patients aged 60-70 years. The disease is characterized by a range of symptoms, which can be remembered using the mnemonic CRABBI. These include hypercalcemia, renal damage, anemia, bleeding, bone lesions, and increased susceptibility to infection. Other features of multiple myeloma include amyloidosis, carpal tunnel syndrome, neuropathy, and hyperviscosity.

      To diagnose multiple myeloma, a range of investigations are required. Blood tests can reveal anemia, renal failure, and hypercalcemia. Protein electrophoresis can detect raised levels of monoclonal IgA/IgG proteins in the serum, while bone marrow aspiration can confirm the diagnosis if the number of plasma cells is significantly raised. Imaging studies, such as whole-body MRI or X-rays, can be used to detect osteolytic lesions.

      The diagnostic criteria for multiple myeloma require one major and one minor criteria or three minor criteria in an individual who has signs or symptoms of the disease. Major criteria include the presence of plasmacytoma, 30% plasma cells in a bone marrow sample, or elevated levels of M protein in the blood or urine. Minor criteria include 10% to 30% plasma cells in a bone marrow sample, minor elevations in the level of M protein in the blood or urine, osteolytic lesions, or low levels of antibodies in the blood. Understanding the features and investigations of multiple myeloma is crucial for early detection and effective treatment.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 4 - A 25-year-old woman presents with a chronic history of diarrhoea, weight loss and...

    Correct

    • A 25-year-old woman presents with a chronic history of diarrhoea, weight loss and fatigue. Based upon the clinical history and examination findings, you suspect she has coeliac disease.
      What is the most appropriate initial investigation?

      Your Answer: IgA tissue transglutaminase (tTGA) antibody

      Explanation:

      Diagnostic Tests for Coeliac Disease

      Coeliac disease is a condition that affects the small intestine and is caused by an intolerance to gluten. There are several diagnostic tests available to help establish a diagnosis of coeliac disease. The first line test is the IgA tissue transglutaminase (tTGA) antibody serology. A positive test indicates that further testing, such as endoscopy and biopsy, is needed for confirmation.

      Before testing, it is important to confirm that the patient has been consuming gluten-containing foods regularly for at least six weeks. HLA testing is not a first line test and should only be carried out in secondary care.

      If the tTGA test is unavailable or weakly positive, IgA endomysial antibody testing may be used as a second line test. Small bowel biopsy is only indicated if serology is positive or equivocal.

      There is no indication for an abdominal CT scan in this scenario. The first line investigation for coeliac disease is serology, and if positive, diagnosis is confirmed or excluded by biopsy of the small bowel at endoscopy.

    • This question is part of the following fields:

      • Immunology
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  • Question 5 - A 50-year-old patient has discovered a lump in her neck and another one...

    Correct

    • A 50-year-old patient has discovered a lump in her neck and another one in her groin. She has been experiencing feverish symptoms for several months and has had to change her bedclothes twice in the last week. Upon examination, smooth, firm, enlarged lymph nodes are noted at both sites. The patient's GP is concerned about the possibility of an underlying lymphoma and has referred her to secondary care for further investigations. A CT scan has not revealed any other lymph nodes. What is the most appropriate diagnosis and staging for this patient?

      Your Answer: On biopsy the malignant lymphoid cells would be likely to have many of the characteristics of their parent cells

      Explanation:

      Lymphomas and their Staging

      Malignancies that arise from lymphocytes can spread to different lymph node groups due to their ability to retain adhesion and signalling receptors. Lymphomas can present at various sites, including bone marrow, gut, and spleen, as normal trafficking of lymphoid cells occurs through these places. Interestingly, higher-grade lymphomas are easier to cure than lower grade lymphomas, despite initially being associated with a higher mortality rate. On the other hand, low-grade lymphomas may not require immediate treatment, but the disease progresses over time, leading to a poorer prognosis.

      To diagnose lymphoma, a biopsy of the affected area, such as a lymph node or bone marrow, is necessary. The Ann Arbor staging system is used to stage lymphomas, with Stage I indicating disease in a single lymph node group and Stage IV indicating extra-nodal involvement other than the spleen. The addition of a ‘B’ signifies the presence of ‘B’ symptoms, which are associated with a poorer prognosis for each disease stage.

      From the examination findings, it is evident that the disease is present on both sides of the diaphragm, indicating at least Stage III lymphoma. the staging of lymphomas is crucial in determining the appropriate treatment plan and predicting the patient’s prognosis.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 6 - A 45-year-old patient arrives at the Emergency department with a one-week history of...

    Correct

    • A 45-year-old patient arrives at the Emergency department with a one-week history of increasing fatigue, nosebleeds, and swollen gums. The admitting physician suspects the possibility of acute leukemia and seeks consultation with their senior colleague. What is the most likely diagnosis for this patient's symptoms?

      Your Answer: He is more likely to be cured than if he was diagnosed with a chronic leukaemia

      Explanation:

      Leukaemia Types and Prognosis

      As with high-grade lymphomas, acute leukaemias have a higher chance of being cured than chronic leukaemias. However, chronic leukaemias such as CLL may not require treatment at the time of diagnosis and may not cause death for many years. Acute leukaemias, on the other hand, have a higher initial mortality rate.

      The diagnosis of acute leukaemia can be made if the blasts account for more than 20% of the bone marrow or peripheral blood, or if there is a blast count with a recognized cytogenetic abnormality associated with AML. Gum hypertrophy is more commonly associated with AML, especially acute monocytic leukaemia.

      Females generally have a better prognosis than males when it comes to acute leukaemias. ALL most commonly arises from B-lymphocyte populations, while AML arising from pre-existing conditions such as the myeloproliferative neoplasms is associated with a poorer prognosis than that arising de novo.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 7 - A 48-year-old woman presents to the clinic with complaints of abdominal pain and...

    Correct

    • A 48-year-old woman presents to the clinic with complaints of abdominal pain and constipation. During the examination, you observe blue lines on the gum margin. She also reports experiencing weakness in her legs over the past few days. What is the probable diagnosis?

      Your Answer: Lead poisoning

      Explanation:

      Lead poisoning is a condition that should be considered when a patient presents with abdominal pain and neurological symptoms, along with acute intermittent porphyria. This condition is caused by defective ferrochelatase and ALA dehydratase function. Symptoms of lead poisoning include abdominal pain, peripheral neuropathy (mainly motor), neuropsychiatric features, fatigue, constipation, and blue lines on the gum margin (which is rare in children and only present in 20% of adult patients).

      To diagnose lead poisoning, doctors typically measure the patient’s blood lead level, with levels greater than 10 mcg/dl considered significant. A full blood count may also be performed, which can reveal microcytic anemia and red cell abnormalities such as basophilic stippling and clover-leaf morphology. Additionally, raised serum and urine levels of delta aminolaevulinic acid may be seen, which can sometimes make it difficult to differentiate from acute intermittent porphyria. Urinary coproporphyrin is also increased, while urinary porphobilinogen and uroporphyrin levels are normal to slightly increased. In children, lead can accumulate in the metaphysis of the bones, although x-rays are not typically part of the standard work-up.

      Various chelating agents are currently used to manage lead poisoning, including dimercaptosuccinic acid (DMSA), D-penicillamine, EDTA, and dimercaprol. These agents work to remove the lead from the body and can help alleviate symptoms.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 8 - Langerhans cells, which are irregularly shaped cells with dendritic processes, an indented nucleus,...

    Correct

    • Langerhans cells, which are irregularly shaped cells with dendritic processes, an indented nucleus, and characteristic intracellular Birbeck granules, are distributed in multiple layers of the epidermis. What is the closest relative of these cells in the human body?

      Your Answer: Monocyte

      Explanation:

      Cell Types in the Skin: Langerhans, Eosinophil, Basophil, Melanocyte, and Merkel Cell

      The skin is composed of various cell types, each with their own unique functions. Langerhans cells, originating from the bone marrow, are antigen-presenting cells found in the epidermis. They process antigens that enter the body via the epidermis and are involved in allergic dermatitis reactions. Eosinophils and basophils are rare in the epidermis, but if present, would be found in cutaneous blood vessels or the dermis and/or hypodermis. Melanocytes, on the other hand, are responsible for producing melanin, which gives skin its color. Langerhans cells lack melanin granules and are more closely related to monocytes. Finally, Merkel cells are dendritic cells found in the stratum basale and are associated with nerve fibers, likely playing an important sensory function. Understanding the different cell types in the skin can help in diagnosing and treating various skin conditions.

    • This question is part of the following fields:

      • Immunology
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  • Question 9 - A biochemist isolated a receptor from a cell and found that it was...

    Correct

    • A biochemist isolated a receptor from a cell and found that it was a two-chained structure composed of α and β polypeptide chains linked by disulfide bonds. Further analysis revealed that the receptor consisted of transmembrane glycoproteins with short cytoplasmic tails and had a single antigen-binding site.
      Which of the following cells most likely contained this receptor if the biochemist had isolated it from a cell of a 60-year-old individual?

      Your Answer: T cell

      Explanation:

      Comparison of Immune Cells: T Cell, Mast Cell, B Cell, Dendritic Cell, and Kupffer Cell

      The immune system is composed of various types of cells that work together to protect the body from foreign invaders. Among these cells are T cells, mast cells, B cells, dendritic cells, and Kupffer cells.

      T cells are characterized by their T-cell receptors (TCRs), which are composed of polypeptide a and b chains connected by disulfide bonds. Each chain of the TCR has a variable and a constant region that folds into an immunoglobulin (Ig)-like domain.

      Mast cells, on the other hand, contain numerous granulocytes and secrete histamine when stimulated. They do not have TCRs.

      B cells have a B-cell receptor (BCR), which is a complex of Ig-a and Ig-b (signal transducers) associated with membrane Ig molecules. The BCR has two antigen-binding sites.

      Dendritic cells are resident macrophages found in the skin. They do not have TCRs.

      Kupffer cells are resident macrophages found in the liver. Like dendritic cells, they do not have TCRs.

      Understanding the characteristics of these immune cells is crucial in developing strategies to combat diseases and infections.

    • This question is part of the following fields:

      • Immunology
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  • Question 10 - A 72-year-old pet shop owner comes in with a persistent cough and difficulty...

    Incorrect

    • A 72-year-old pet shop owner comes in with a persistent cough and difficulty breathing during physical activity. A chest CT scan reveals a ground-glass appearance. What is the most frequently linked mechanism responsible for this reaction?

      Your Answer: Type I hypersensitivity reaction

      Correct Answer: Type III hypersensitivity reaction

      Explanation:

      Hypersensitivity Reactions: Types and Examples

      Hypersensitivity reactions are immune responses that occur when the body reacts to a harmless substance as if it were harmful. There are four types of hypersensitivity reactions, each with different mechanisms and clinical presentations.

      Type I hypersensitivity reaction is an immediate reaction mediated by IgE in response to an environmental antigen. Mast cell and basophil degranulation result in the release of histamine, causing symptoms such as allergic rhinitis and systemic urticaria.

      Type II hypersensitivity reaction is an antibody-mediated reaction that results in cellular injury. Examples include incompatible blood transfusions, haemolytic disease of the newborn, and autoimmune haemolytic anaemias.

      Type III hypersensitivity reaction is an immune complex-mediated reaction. Immune complexes are lattices of antibody and antigen that trigger an inflammatory response when not cleared from the circulation. Extrinsic allergic alveolitis, or bird fancier’s lung, is an example of this type of reaction.

      Type IV hypersensitivity reaction is a delayed reaction involving T helper cells that become activated upon contact with an antigen. Cytokine release from sensitised T-cells leads to macrophage-induced phagocytosis. This type of reaction is seen in contact dermatitis and some cases of extrinsic allergic alveolitis.

      Anaphylaxis is a type I-mediated hypersensitivity reaction that results in rapid respiratory and circulatory compromise. Skin and mucosal changes, such as rash with wheal and angio-oedema, are also present.

      In summary, hypersensitivity reactions can have different mechanisms and clinical presentations. Understanding the type of reaction is important for proper diagnosis and management.

    • This question is part of the following fields:

      • Immunology
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  • Question 11 - A 54-year-old man comes to the clinic complaining of fever and night sweats...

    Correct

    • A 54-year-old man comes to the clinic complaining of fever and night sweats that have been ongoing for several months. He reports a weight loss of 8 kg during this time and smokes half a pack of cigarettes per day. His temperature is 38 ºC, and he has splenomegaly on physical examination. No lymphadenopathy is observed. Laboratory results show a leukocyte count of 60 * 109, and a low leukocyte alkaline phosphatase level.

      What is the most likely finding in this patient?

      Your Answer: t(9;22) translocation

      Explanation:

      Genetics of Haematological Malignancies

      Haematological malignancies are cancers that affect the blood, bone marrow, and lymphatic system. These cancers are often associated with specific genetic abnormalities, such as translocations. Here are some common translocations and their associated haematological malignancies:

      – Philadelphia chromosome (t(9;22)): This translocation is present in more than 95% of patients with chronic myeloid leukaemia (CML). It results in the fusion of the Abelson proto-oncogene with the BCR gene on chromosome 22, creating the BCR-ABL gene. This gene codes for a fusion protein with excessive tyrosine kinase activity, which is a poor prognostic indicator in acute lymphoblastic leukaemia (ALL).

      – t(15;17): This translocation is seen in acute promyelocytic leukaemia (M3) and involves the fusion of the PML and RAR-alpha genes.

      – t(8;14): Burkitt’s lymphoma is associated with this translocation, which involves the translocation of the MYC oncogene to an immunoglobulin gene.

      – t(11;14): Mantle cell lymphoma is associated with the deregulation of the cyclin D1 (BCL-1) gene.

      – t(14;18): Follicular lymphoma is associated with increased BCL-2 transcription due to this translocation.

      Understanding the genetic abnormalities associated with haematological malignancies is important for diagnosis, prognosis, and treatment.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 12 - A 38-year-old with a known diagnosis of G6PD deficiency presents with jaundice and...

    Correct

    • A 38-year-old with a known diagnosis of G6PD deficiency presents with jaundice and suspected acute haemolysis. He had recently been treated for a suspected urinary tract infection with nitrofurantoin. Blood tests reveal the following results:

      Hb 94 g/L (135-180)
      Platelets 210* 109/L (150 - 400)
      WBC 7.2*109/L (4.0 - 11.0)
      Reticulocytes 8.0% (0.2-2.0)

      What underlying process is likely occurring in response to these findings?

      Your Answer: Haptoglobin binds free haemoglobin

      Explanation:

      Haptoglobin plays a crucial role in binding free haemoglobin following haemolysis. This binding forms a complex that can be cleared and metabolized by macrophages through CD163 receptors. This process is essential in preventing local toxicity from haemoglobin degradation products, such as free radicals. Therefore, reduced haptoglobin levels upon testing can indicate intravascular haemolysis. It is important to note that haemopexin binds free haem, not haemoglobin itself, and haptoglobin does not bind complexed haemoglobin or free heme.

      Understanding Haemolytic Anaemias by Site

      Haemolytic anaemias can be classified by the site of haemolysis, either intravascular or extravascular. In intravascular haemolysis, free haemoglobin is released and binds to haptoglobin. As haptoglobin becomes saturated, haemoglobin binds to albumin forming methaemalbumin, which can be detected by Schumm’s test. Free haemoglobin is then excreted in the urine as haemoglobinuria and haemosiderinuria. Causes of intravascular haemolysis include mismatched blood transfusion, red cell fragmentation due to heart valves, TTP, DIC, HUS, paroxysmal nocturnal haemoglobinuria, and cold autoimmune haemolytic anaemia.

      On the other hand, extravascular haemolysis occurs when red blood cells are destroyed by macrophages in the spleen or liver. This type of haemolysis is commonly seen in haemoglobinopathies such as sickle cell anaemia and thalassaemia, hereditary spherocytosis, haemolytic disease of the newborn, and warm autoimmune haemolytic anaemia.

      It is important to understand the site of haemolysis in order to properly diagnose and treat haemolytic anaemias. While both intravascular and extravascular haemolysis can lead to anaemia, the underlying causes and treatment approaches may differ.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 13 - A newly diagnosed patient with acute myeloid leukaemia (AML) is about to begin...

    Incorrect

    • A newly diagnosed patient with acute myeloid leukaemia (AML) is about to begin treatment. What would be a favorable prognostic factor for this individual?

      Your Answer: Performance status 3

      Correct Answer: Acute promyelocytic leukaemia (APML) subtype

      Explanation:

      Prognostic Factors in Acute Myeloid Leukemia

      Acute myeloid leukemia (AML) is a type of cancer that affects the blood and bone marrow. The APML subtype of AML has a higher five-year survival rate of 70% compared to the average rate of 25%. However, it is a medical emergency upon presentation due to the risk of coagulopathy, tumor lysis, and life-threatening infections. Urgent treatment with ATRA chemotherapy is necessary. Younger patients tend to have a better prognosis and can tolerate intensive chemotherapy better. Certain cytogenetic changes, such as t(15;17) in APML and t(8;21) and inv(16), are associated with a favorable prognosis. However, complex cytogenetics are not. A performance status of 3, which indicates that an individual spends more than 50% of the day in bed, is not ideal for intensive chemotherapy. AML that arises from a pre-existing condition, such as a myeloproliferative neoplasm, has a worse prognosis than AML that arises de novo.

      Overall, the prognostic factors in AML is crucial for determining the appropriate treatment plan and predicting outcomes.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 14 - A newborn preterm-baby is observed to be jaundiced and having difficulty with feeding...

    Correct

    • A newborn preterm-baby is observed to be jaundiced and having difficulty with feeding by the attending midwife. Bilirubin levels are measured, which rapidly increase throughout the day despite initiating phototherapy. The pregnancy was complicated by preterm labor; the mother also has a 3-year old child who is well and had no complications at birth. A direct Coombs test is performed and found to be positive; subsequently Rhesus haemolytic disease of the newborn is confirmed. What is the best example of the underlying cause of haemolysis in this preterm baby?

      Your Answer: IgG antibodies attacking the infants red cells

      Explanation:

      Understanding the Causes of Haemolytic Disease of the Newborn

      Haemolytic disease of the newborn is a condition that occurs when a mother’s antibodies attack her infant’s red blood cells. This can happen due to a variety of reasons, including rhesus factor incompatibility and immune complex deposition.

      Rhesus factor incompatibility occurs when a rhesus-negative mother has previously been sensitised to the rhesus antigen, usually from a previous rhesus-positive pregnancy or blood transfusion. In subsequent pregnancies, IgG antibodies made by the mother due to previous exposure can cross the placenta and attack the infant’s red blood cells.

      Immune complex deposition, which is a type III hypersensitivity reaction, can also cause haemolysis. This occurs when immune complexes deposit in tissues and trigger an inflammatory response. Examples of conditions that can cause this type of reaction include systemic lupus erythematosus and farmer’s lung.

      It’s important to note that haemolysis in haemolytic disease of the newborn is triggered by maternal IgG antibodies, not IgE antibodies. Anaphylactic reactions, which are triggered by IgE antibodies, are a separate issue.

      Understanding the causes of haemolytic disease of the newborn is crucial for proper diagnosis and treatment. Pregnant women should be screened for rhesus factor incompatibility and other potential risk factors to prevent this condition from occurring.

    • This question is part of the following fields:

      • Immunology
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  • Question 15 - A 50-year-old woman has recently been diagnosed with breast cancer and is now...

    Incorrect

    • A 50-year-old woman has recently been diagnosed with breast cancer and is now undergoing treatment with docetaxel. What is the mechanism of action for this particular treatment?

      Your Answer: It inhibits topoisomerase I which prevents relaxation of supercoiled DNA

      Correct Answer: It prevents microtubule depolymerisation and disassembly, decreasing free tubulin

      Explanation:

      Docetaxel, a member of the taxane family, disrupts microtubule function by preventing depolymerisation and disassembly. This reduces free tubulin and halts cell division. Irinotecan inhibits topoisomerase I, preventing relaxation of supercoiled DNA, leading to DNA damage and cell death. Methotrexate inhibits dihydrofolate reductase and thymidylate synthesis, slowing and stopping DNA and protein synthesis necessary for normal cell cycle. Cisplatin binds to DNA, cross-linking and inhibiting replication. Doxorubicin stabilises the topoisomerase II complex, inhibiting DNA and RNA synthesis necessary for cell division.

      Cytotoxic agents are drugs that are used to kill cancer cells. There are several types of cytotoxic agents, each with their own mechanism of action and potential adverse effects. Alkylating agents, such as cyclophosphamide, work by causing cross-linking in DNA. However, they can also cause haemorrhagic cystitis, myelosuppression, and transitional cell carcinoma. Cytotoxic antibiotics, like bleomycin and anthracyclines, degrade preformed DNA and stabilize DNA-topoisomerase II complex, respectively. However, they can also cause lung fibrosis and cardiomyopathy. Antimetabolites, such as methotrexate and fluorouracil, inhibit dihydrofolate reductase and thymidylate synthesis, respectively. However, they can also cause myelosuppression, mucositis, and liver or lung fibrosis. Drugs that act on microtubules, like vincristine and docetaxel, inhibit the formation of microtubules and prevent microtubule depolymerisation & disassembly, respectively. However, they can also cause peripheral neuropathy, myelosuppression, and paralytic ileus. Topoisomerase inhibitors, like irinotecan, inhibit topoisomerase I, which prevents relaxation of supercoiled DNA. However, they can also cause myelosuppression. Other cytotoxic drugs, such as cisplatin and hydroxyurea, cause cross-linking in DNA and inhibit ribonucleotide reductase, respectively. However, they can also cause ototoxicity, peripheral neuropathy, hypomagnesaemia, and myelosuppression.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 16 - A 45-year-old woman presents to her GP with a four-week history of dysphagia,...

    Correct

    • A 45-year-old woman presents to her GP with a four-week history of dysphagia, anorexia and weight loss. She has had a hoarse voice for several months.

      She has a 40 pack-year smoking history, starting from the age of 16 years. She drinks 30 units a week in the form of binge drinking beer over the weekend. She admits to having a very poor diet consisting mostly of fish and chips. She is noted to have a body mass index of 38kg/m².

      The GP refers her under a two-week wait for suspicion of oesophageal cancer.

      What risk factors contributed to her increased likelihood of developing this disease?

      Your Answer: Nitrosamines

      Explanation:

      Exposure to nitrosamines is a known risk factor for the development of oesophageal and gastric cancer, particularly squamous cell carcinoma of the oesophagus. Nitrosamines are present in high levels in cigarette smoke, which is a significant source of exposure for this patient. Binge drinking of beer can also lead to high levels of nitrosamine exposure. Additionally, nitrosamines can be found in certain fried foods, such as fish and chips, as well as some cheeses.

      Aflatoxin, which is produced by Aspergillus species, is another known risk factor for cancer. Specifically, it increases the risk of developing hepatocellular carcinoma.

      Aniline dyes, which are commonly used in industrial dyeing and the rubber industry, have been linked to an increased risk of developing transitional cell carcinoma of the bladder.

      Asbestos, which was once widely used in insulation, building materials, and construction, is a well-known carcinogen that increases the risk of developing mesothelioma and bronchial cancers.

      Understanding Carcinogens and Their Link to Cancer

      Carcinogens are substances that have the potential to cause cancer. These substances can be found in various forms, including chemicals, radiation, and viruses. Aflatoxin, which is produced by Aspergillus, is a carcinogen that can cause liver cancer. Aniline dyes, on the other hand, can lead to bladder cancer, while asbestos is known to cause mesothelioma and bronchial carcinoma. Nitrosamines are another type of carcinogen that can cause oesophageal and gastric cancer, while vinyl chloride can lead to hepatic angiosarcoma.

      It is important to understand the link between carcinogens and cancer, as exposure to these substances can increase the risk of developing the disease. By identifying and avoiding potential carcinogens, individuals can take steps to reduce their risk of cancer. Additionally, researchers continue to study the effects of various substances on the body, in order to better understand the mechanisms behind cancer development and to develop new treatments and prevention strategies. With continued research and education, it is possible to reduce the impact of carcinogens on human health.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 17 - A 78-year-old woman has been diagnosed with acute myeloid leukaemia (AML). During an...

    Incorrect

    • A 78-year-old woman has been diagnosed with acute myeloid leukaemia (AML). During an MDT meeting, it was decided that her first-line treatment will involve chemotherapy. The chosen drug is an antimetabolite that acts as a pyrimidine antagonist, inhibiting DNA polymerase and interfering with DNA synthesis.

      What chemotherapy drug is most likely being prescribed based on the above mechanism of action?

      Your Answer: Rituximab

      Correct Answer: Cytarabine

      Explanation:

      Cytarabine is a medication used in chemotherapy to treat acute myeloid leukaemia (AML). It works by interfering with DNA synthesis during the S-phase of the cell cycle and inhibiting DNA polymerase.

      Allopurinol is a medication that inhibits xanthine oxidase, which prevents the production of uric acid. It is commonly used to treat gout, but can also be used to prevent hyperuricaemia in high-grade lymphoma and leukaemia before chemotherapy treatment.

      Methotrexate works by inhibiting dihydrofolate reductase and thymidylate synthesis. It is used to treat rheumatoid arthritis and various types of cancer.

      Ondansetron is an anti-emetic medication that is used to prevent nausea during chemotherapy treatment. It works by selectively blocking serotonin receptors (5-HT3) in the chemoreceptor trigger zone (CTZ) of the medulla.

      Cytotoxic agents are drugs that are used to kill cancer cells. There are several types of cytotoxic agents, each with their own mechanism of action and potential adverse effects. Alkylating agents, such as cyclophosphamide, work by causing cross-linking in DNA. However, they can also cause haemorrhagic cystitis, myelosuppression, and transitional cell carcinoma. Cytotoxic antibiotics, like bleomycin and anthracyclines, degrade preformed DNA and stabilize DNA-topoisomerase II complex, respectively. However, they can also cause lung fibrosis and cardiomyopathy. Antimetabolites, such as methotrexate and fluorouracil, inhibit dihydrofolate reductase and thymidylate synthesis, respectively. However, they can also cause myelosuppression, mucositis, and liver or lung fibrosis. Drugs that act on microtubules, like vincristine and docetaxel, inhibit the formation of microtubules and prevent microtubule depolymerisation & disassembly, respectively. However, they can also cause peripheral neuropathy, myelosuppression, and paralytic ileus. Topoisomerase inhibitors, like irinotecan, inhibit topoisomerase I, which prevents relaxation of supercoiled DNA. However, they can also cause myelosuppression. Other cytotoxic drugs, such as cisplatin and hydroxyurea, cause cross-linking in DNA and inhibit ribonucleotide reductase, respectively. However, they can also cause ototoxicity, peripheral neuropathy, hypomagnesaemia, and myelosuppression.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 18 - Infusion with which of the following blood products is most likely to result...

    Incorrect

    • Infusion with which of the following blood products is most likely to result in an urticarial reaction?

      Rewritten: Infusion of which blood product is most likely to cause urticarial reactions?

      Your Answer: Platelets

      Correct Answer: Fresh frozen plasma

      Explanation:

      Transfusion of packed red cells is frequently associated with pyrexia as an adverse event, while infusion of FFP often leads to urticaria as the most common adverse event.

      Blood product transfusion complications can be categorized into immunological, infective, and other complications. Immunological complications include acute haemolytic reactions, non-haemolytic febrile reactions, and allergic/anaphylaxis reactions. Infective complications may arise due to transmission of vCJD, although measures have been taken to minimize this risk. Other complications include transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), hyperkalaemia, iron overload, and clotting.

      Non-haemolytic febrile reactions are thought to be caused by antibodies reacting with white cell fragments in the blood product and cytokines that have leaked from the blood cell during storage. These reactions may occur in 1-2% of red cell transfusions and 10-30% of platelet transfusions. Minor allergic reactions may also occur due to foreign plasma proteins, while anaphylaxis may be caused by patients with IgA deficiency who have anti-IgA antibodies.

      Acute haemolytic transfusion reaction is a serious complication that results from a mismatch of blood group (ABO) which causes massive intravascular haemolysis. Symptoms begin minutes after the transfusion is started and include a fever, abdominal and chest pain, agitation, and hypotension. Treatment should include immediate transfusion termination, generous fluid resuscitation with saline solution, and informing the lab. Complications include disseminated intravascular coagulation and renal failure.

      TRALI is a rare but potentially fatal complication of blood transfusion that is characterized by the development of hypoxaemia/acute respiratory distress syndrome within 6 hours of transfusion. On the other hand, TACO is a relatively common reaction due to fluid overload resulting in pulmonary oedema. As well as features of pulmonary oedema, the patient may also be hypertensive, a key difference from patients with TRALI.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 19 - A 60-year-old man comes to the clinic complaining of a lump on the...

    Incorrect

    • A 60-year-old man comes to the clinic complaining of a lump on the left side of his neck. During the examination, a firm and non-tender swelling is found over the angle of the mandible. The patient also displays asymmetrical facial features, including drooping of the angle of the mouth on the left and an inability to close his left eyelid. What is the probable diagnosis?

      Your Answer: Bell's palsy

      Correct Answer: Malignant parotid tumour

      Explanation:

      Parotid Mass and Facial Nerve Involvement

      Swelling over the angle of the mandible is a common site for a parotid mass. The majority of these masses are benign, with pleomorphic adenomas being the most common type. However, Warthin’s tumour is also a possibility. Malignancy is indicated when there is involvement of the facial nerve, which is a feature found in malignant parotid tumours. Bilateral facial nerve involvement with bilateral parotid swelling may be indicative of sarcoidosis. Parotitis, on the other hand, causes painful acute swelling over the parotid gland with redness. Bell’s palsy is a benign and often temporary paralysis of the facial nerve, which is usually preceded by a viral infection that causes inflammation and paralysis.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 20 - A 49-year-old female presents to her family physician with complaints of post-coital pain....

    Correct

    • A 49-year-old female presents to her family physician with complaints of post-coital pain. She initially attributed it to her age, but lately, she has been experiencing a constant dull pain in her pelvis. Additionally, she reports having a foul-smelling discharge from her vagina. Her medical and surgical history is unremarkable, but she mentions having multiple sexual partners during her teenage years and twenties. She has been smoking ten cigarettes a day for the past decade and does not consume alcohol. During the examination, the doctor discovers an irregular mass on her cervix. What is the primary mechanism behind the most significant risk factor for this patient's condition?

      Your Answer: Human papillomavirus 16 and 18 produces oncoproteins which causes inhibition of the tumor suppressor genes causing cervical carcinoma

      Explanation:

      The patient is displaying typical signs and symptoms of cervical carcinoma, with a constant dull pelvic pain indicating possible invasion of pelvic structures and nerves. The strongest risk factor for this patient is having had multiple sexual partners at a young age, which increases the likelihood of being infected with the human papillomavirus.

      1: Multiple sexual partners are the strongest risk factor for cervical carcinoma due to the increased chance of contracting the human papillomavirus, specifically the 16 and 18 viral strains that inhibit the tumor suppressor genes p53 and RB, triggering carcinogenesis.
      2: While cigarette smoking can have an oncogenic effect, it is not the primary risk factor in this case.
      3: HIV is a risk factor for cervical carcinoma, but it is less common than the human papillomavirus.
      4: The human papillomavirus is the primary risk factor, but it does not activate oncogenes. Instead, it inhibits tumor suppressor genes.
      5: Age alone is not a risk factor for cervical carcinoma. However, an older person who has been exposed to the human papillomavirus may have a higher risk due to the longer exposure time for the virus to induce carcinogenesis via the inhibition of tumor suppressor genes.

      HPV Infection and Cervical Cancer

      Human papillomavirus (HPV) infection is the primary risk factor for cervical cancer, with subtypes 16, 18, and 33 being the most carcinogenic. Other common subtypes, such as 6 and 11, are associated with genital warts but are not carcinogenic. When endocervical cells become infected with HPV, they may undergo changes that lead to the development of koilocytes. These cells have distinct characteristics, including an enlarged nucleus, irregular nuclear membrane contour, hyperchromasia (darker staining of the nucleus), and a perinuclear halo. These changes are important diagnostic markers for cervical cancer and can be detected through Pap smears or other screening methods. Early detection and treatment of HPV infection and cervical cancer can greatly improve outcomes and reduce the risk of complications.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 21 - A 48-year-old engineer presents with a lump in his neck. He first noticed...

    Correct

    • A 48-year-old engineer presents with a lump in his neck. He first noticed the swelling in the lower right neck two months ago, and initially thought it would go away by itself; however, if anything, it seems to have got bigger. The patient has also noticed that he tends to be very tired at the end of the day. He mentions that he has also been experiencing night sweats.
      On examination, the patient is found to have numerous enlarged cervical lymph nodes, as well as lymphadenopathy in the axilla. The patient is further investigated after which he is diagnosed with lymphoma.
      From which cells do B and T lymphocytes originate?

      Your Answer: Lymphoid stem cells

      Explanation:

      Overview of Immune System Cells and Proteins

      The immune system is composed of various cells and proteins that work together to protect the body from foreign invaders. Here are some key components:

      Lymphoid stem cells: These cells can differentiate into B lymphocytes, T lymphocytes, plasma cells, and natural killer cells.

      Basophils: These cells are involved in inflammatory and allergic reactions. They contain heparin and histamine.

      Myeloid stem cells: These cells can differentiate into various types of white blood cells, including monocytes, macrophages, neutrophils, basophils, eosinophils, and dendritic cells, as well as red blood cells and platelets.

      CD40: This protein is found on antigen-presenting cells and is required for their activation.

      Plasma cells: These cells are antibody-secreting white blood cells that originate from B cells in the bone marrow and differentiate in lymph nodes.

    • This question is part of the following fields:

      • Immunology
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  • Question 22 - A 4-year-old boy visits the doctor complaining of occasional vomiting. He appears to...

    Incorrect

    • A 4-year-old boy visits the doctor complaining of occasional vomiting. He appears to be unstable while walking and his mother reports that he frequently complains of headaches. What is the probable diagnosis?

      Your Answer: Acute myeloid leukaemia

      Correct Answer: Medulloblastoma

      Explanation:

      Diagnosis of a Posterior Fossa Tumor in a Young Girl

      This young girl is showing symptoms of a posterior fossa tumor, which affects the cerebellar function. Ataxia, slurred speech, and double vision are common symptoms of this type of tumor. Additionally, headaches and vomiting are signs of increased intracranial pressure. The most likely diagnosis for this young girl is medulloblastoma, which is the most frequent posterior fossa tumor in children.

      Craniopharyngioma is an anterior fossa tumor that arises from the floor of the pituitary, making it an unlikely diagnosis for this young girl. Acute myeloid leukemia is rare in children and has a low rate of CNS involvement, unlike acute lymphoblastic leukemia. Ataxia telangiectasia is a hereditary condition that causes degeneration of multiple spinal cord tracts, but it would not present with features of a space-occupying lesion. Becker’s muscular dystrophy is an X-linked condition that causes weakness in boys.

      In summary, this young girl’s symptoms suggest a posterior fossa tumor, with medulloblastoma being the most likely diagnosis. It is important to accurately diagnose and treat this condition to ensure the best possible outcome for the patient.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 23 - A 20-year-old male patient comes in with a low impact fracture of his...

    Incorrect

    • A 20-year-old male patient comes in with a low impact fracture of his right femur. Upon examination, an x-ray reveals a growth located at the metaphysis that elevates the periosteum and appears to extend into the surrounding soft tissues. What is the probable diagnosis?

      Your Answer: Ewing sarcoma

      Correct Answer: Osteosarcoma

      Explanation:

      Common Types of Bone Tumours

      Osteosarcomas are the most frequent primary bone malignancy, often occurring in the metaphysis around the knee. They are more common in boys and affect those aged between 14 and 20 years old. Symptoms include pain, low impact fracture, or a mass. On an x-ray, they appear as an area of new bone beneath the periosteum, lifting it up, known as Codman’s triangle. Another feature is sunray spiculation, where opaque lines of osteosarcoma grow into adjacent soft tissues.

      Chondrosarcoma is a malignant tumour of cartilage that usually develops from benign chondromas, often in hereditary multiple exostoses. Ewing sarcoma is a tumour of unknown origin that develops in limb girdles or the diaphysis of long bones. It has a characteristic onion appearance on x-ray, with concentric rings of new bone formation. Bone metastases are rare in children, and there are no features to suggest a primary tumour, although it should be considered.

      Osteoid osteoma is a benign cystic tumour that occurs in the long bones of young men and teenagers. It causes severe pain and shows as local cortical sclerosis but does not invade into soft tissues. the different types of bone tumours and their characteristics is crucial for early detection and treatment.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 24 - A patient in their 50s is undergoing investigation for anaemia. Blood tests show...

    Correct

    • A patient in their 50s is undergoing investigation for anaemia. Blood tests show a normocytic, hypochromic anaemia with an increased red cell distribution width. A dimorphic picture is observed on a blood film. What is the most probable explanation for the underlying pathophysiology?

      Your Answer: Mixed iron and folate deficiency

      Explanation:

      The dimorphic blood film is a rare occurrence that can be seen in only a few medical conditions. One such condition is ACD, which is characterized by disordered iron metabolism, reduced erythropoietin response, and decreased erythropoiesis. However, the exact pathophysiology of ACD is not yet fully understood. In CRF, the problem is compounded by a reduction in EPO production and increased bleeding tendency.

      Another cause of a microcytosis disproportionate to the degree of anemia is β-thalassemia trait. This condition is often mistaken for iron deficiency, but it does not respond to iron supplementation. Iron deficiency typically causes a hypochromic, microcytic anemia with some variation in red blood size, but not a dimorphic picture. However, partially treated iron deficiency anemia can lead to a dimorphic blood film.

      In summary, the dimorphic blood film is a key feature that can be seen in only a limited number of medical conditions. The underlying causes of this condition is crucial for accurate diagnosis and appropriate treatment.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 25 - A 63-year-old woman is referred to dermatology for evaluation of a concerning lesion...

    Correct

    • A 63-year-old woman is referred to dermatology for evaluation of a concerning lesion on her arm. She reports that it was previously a uniform shape and approximately 5 mm in size, but has since grown and become irregular in shape with multiple colors. A biopsy confirms advanced melanoma and she is started on ipilimumab. What is the mechanism of action for this medication?

      Your Answer: Blockage of Cytotoxic T Lymphocyte-associated Protein 4 (CTLA-4)

      Explanation:

      Ipilimumab is a type of immune checkpoint inhibitor that is used to treat melanoma by blocking CTLA-4. Other immune checkpoint inhibitors, such as nivolumab and pembrolizumab, block PD-1 and can be used to treat various cancers including melanoma, Hodgkin’s lymphoma, and non-small cell lung cancer. Atezolizumab and durvalumab are examples of immune checkpoint inhibitors that block PD-L1 and can be used to treat lung and urothelial cancer. Alkylating agents like cyclophosphamide exert their effect by cross-linking DNA, while medications like vincristine and vinblastine inhibit the formation of microtubules.

      Understanding Immune Checkpoint Inhibitors

      Immune checkpoint inhibitors are a type of immunotherapy that is becoming increasingly popular in the treatment of certain types of cancer. Unlike traditional therapies such as chemotherapy, these targeted treatments work by harnessing the body’s natural anti-cancer immune response. They boost the immune system’s ability to attack and destroy cancer cells, rather than directly affecting their growth and proliferation.

      T-cells are an essential part of our immune system that helps destroy cancer cells. However, some cancer cells produce high levels of proteins that turn T-cells off. Checkpoint inhibitors block this process and reactivate and increase the body’s T-cell population, enhancing the immune system’s ability to recognize and fight cancer cells.

      There are different types of immune checkpoint inhibitors, including Ipilimumab, Nivolumab, Pembrolizumab, Atezolizumab, Avelumab, and Durvalumab. These drugs block specific proteins found on T-cells and cancer cells, such as CTLA-4, PD-1, and PD-L1. They are administered by injection or intravenous infusion and can be given as a single-agent treatment or combined with chemotherapy or each other.

      However, the mechanism of action of these drugs can result in side effects termed ‘Immune-related adverse events’ that are inflammatory and autoimmune in nature. This is because all immune cells are boosted by these drugs, not just the ones that target cancer. The overactive T-cells can produce side effects such as dry, itchy skin and rashes, nausea and vomiting, decreased appetite, diarrhea, tiredness and fatigue, shortness of breath, and a dry cough. Management of such side effects reflects the inflammatory nature, often involving corticosteroids. It is important to monitor liver, kidney, and thyroid function as these drugs can affect these organs.

      In conclusion, the early success of immune checkpoint inhibitors in solid tumors has generated tremendous interest in further developing and exploring these strategies across the oncology disease spectrum. Ongoing testing in clinical trials creates new hope for patients affected by other types of disease.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 26 - Samantha is a 42-year-old woman who has presented with new-onset urinary retention over...

    Incorrect

    • Samantha is a 42-year-old woman who has presented with new-onset urinary retention over the past 8 hours. She was previously diagnosed with non-Hodgkin's lymphoma and is currently undergoing chemotherapy treatment for this. She notes that prior to this, her urine had a reddish-tinge.

      A 3-way catheter was inserted and blood-stained urine with clots was seen within the catheter bag. Urinalysis showed significant blood but no leukocytes or nitrites were seen. A cystoscopy performed did not show any masses and biopsies taken did not show any malignancy. It was felt that this was a likely side effect of one of these chemotherapy agents.

      What is the underlying mechanism of action of the culprit chemotherapy agent?

      Your Answer: Inhibits microtubule formation

      Correct Answer: Promotes cross-linking of DNA

      Explanation:

      The chemotherapy regime R-CHOP, which is likely being used to manage the patient’s non-Hodgkin’s lymphoma, includes cyclophosphamide, a drug that functions as an alkylating agent and promotes cross-linking of DNA. This can lead to haemorrhagic cystitis, which is likely the cause of the patient’s haematuria. Other drugs in the regime have different mechanisms of action, such as inhibition of microtubule formation with vincristine, inhibition of topoisomerase II and DNA/RNA synthesis with doxorubicin, and monoclonal antibody targeting of CD20 with rituximab. Pyrimidine analogues like 5-fluorouracil, which block thymidylate synthase and induce cell cycle arrest and apoptosis, are not commonly used in the management of non-Hodgkin’s lymphoma.

      Cytotoxic agents are drugs that are used to kill cancer cells. There are several types of cytotoxic agents, each with their own mechanism of action and potential adverse effects. Alkylating agents, such as cyclophosphamide, work by causing cross-linking in DNA. However, they can also cause haemorrhagic cystitis, myelosuppression, and transitional cell carcinoma. Cytotoxic antibiotics, like bleomycin and anthracyclines, degrade preformed DNA and stabilize DNA-topoisomerase II complex, respectively. However, they can also cause lung fibrosis and cardiomyopathy. Antimetabolites, such as methotrexate and fluorouracil, inhibit dihydrofolate reductase and thymidylate synthesis, respectively. However, they can also cause myelosuppression, mucositis, and liver or lung fibrosis. Drugs that act on microtubules, like vincristine and docetaxel, inhibit the formation of microtubules and prevent microtubule depolymerisation & disassembly, respectively. However, they can also cause peripheral neuropathy, myelosuppression, and paralytic ileus. Topoisomerase inhibitors, like irinotecan, inhibit topoisomerase I, which prevents relaxation of supercoiled DNA. However, they can also cause myelosuppression. Other cytotoxic drugs, such as cisplatin and hydroxyurea, cause cross-linking in DNA and inhibit ribonucleotide reductase, respectively. However, they can also cause ototoxicity, peripheral neuropathy, hypomagnesaemia, and myelosuppression.

    • This question is part of the following fields:

      • Haematology And Oncology
      28.9
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  • Question 27 - A 10-year-old boy with a history of sickle cell anaemia arrives at the...

    Incorrect

    • A 10-year-old boy with a history of sickle cell anaemia arrives at the Emergency department complaining of a painful and swollen left leg that has been bothering him for the past two days. He has also been experiencing fevers and overall malaise. Upon examination, he is found to have a high fever and an extremely tender lower leg. What is the most probable organism responsible for his current condition?

      Your Answer: Haemophilus influenzae

      Correct Answer:

      Explanation:

      Salmonella and Staphylococcus aureus as Causes of Osteomyelitis

      Salmonella species are responsible for more than half of osteomyelitis cases in patients with sickle cell disease. The higher incidence of salmonella infections is due to various factors. The gut wall’s micro-infarcts allow the bacteria to enter the bloodstream, causing infection. Additionally, impaired splenic function leads to a weakened immune response against the pathogen.

      On the other hand, Staphylococcus aureus is the most common organism that causes osteomyelitis in the general population. Although other organisms can also cause osteomyelitis, they are less frequently implicated.

    • This question is part of the following fields:

      • Haematology And Oncology
      37.9
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  • Question 28 - A 25-year-old male is getting a routine check-up from his family doctor before...

    Correct

    • A 25-year-old male is getting a routine check-up from his family doctor before starting a new workout regimen at the gym. He has a clean medical history and does not smoke or drink. He is currently pursuing a graduate degree in political science. The doctor orders a CBC and other tests.

      The patient returns to the doctor's office a week later for the test results. The CBC shows that his platelet count is low. However, he does not have any signs of bleeding from his nose or mouth, and there are no rashes on his skin.

      The doctor suspects that this may be due to platelet in vitro agglutination.

      What could have caused this condition?

      Your Answer: Ethylenediaminetetraacetic acid (EDTA)

      Explanation:

      EDTA is known to induce pseudothrombocytopenia, which is a condition where platelet counts are falsely reported as low due to EDTA-dependent platelet aggregation. On the other hand, sodium fluoride inhibits glycolysis and prevents enzymes from functioning, leading to the depletion of substrates like glucose during storage. While sodium citrate, sodium oxalate, and lithium heparin are all anticoagulants commonly found in vacutainers, they are not linked to thrombocytopenia.

      Causes of Thrombocytopenia

      Thrombocytopenia is a medical condition characterized by a low platelet count in the blood. The severity of thrombocytopenia can vary, with some cases being more severe than others. Severe thrombocytopenia can be caused by conditions such as immune thrombocytopenia (ITP), disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura (TTP), and haematological malignancy. On the other hand, moderate thrombocytopenia can be caused by heparin-induced thrombocytopenia (HIT), drug-induced factors such as quinine, diuretics, sulphonamides, aspirin, and thiazides, alcohol, liver disease, hypersplenism, viral infections such as EBV, HIV, and hepatitis, pregnancy, SLE/antiphospholipid syndrome, and vitamin B12 deficiency. It is important to note that pseudothrombocytopenia can also occur as a result of using EDTA as an anticoagulant.

    • This question is part of the following fields:

      • Haematology And Oncology
      11.5
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  • Question 29 - A 35-year-old woman has been admitted to the Acute Medical Unit with shortness...

    Incorrect

    • A 35-year-old woman has been admitted to the Acute Medical Unit with shortness of breath, dizziness and feeling generally lethargic. Her full blood count reveals that her haemoglobin is 60 g/l. She reports that she suffers from menorrhagia. It is decided that she requires a blood transfusion. A few minutes after the transfusion begins, she develops a fever, lower back pain and starts vomiting.
      What is the diagnostic tool used to identify an ABO incompatibility transfusion reaction?

      Your Answer: Indirect antiglobulin test

      Correct Answer: Direct antiglobulin test (Coombs test)

      Explanation:

      Diagnostic Tests for Blood Transfusion Reactions

      Blood transfusion reactions can be life-threatening if not diagnosed and treated promptly. Several diagnostic tests are available to identify the cause of haemolysis and diagnose an ABO incompatibility transfusion reaction. Here are some of the commonly used tests:

      Direct Antiglobulin Test (Coombs Test)
      This test is used to identify whether red blood cells have antibodies attached to their surface. It is useful in diagnosing the cause of haemolysis in ABO incompatibility following transfusion, haemolytic disease of the newborn, drug-induced anaemia, and other autoimmune conditions that cause the destruction of red blood cells.

      Erythrocyte Sedimentation Rate (ESR)
      ESR measures the sedimentation of erythrocytes in a tall, thin tube of blood. Although it is not a useful test to establish the cause of haemolysis and diagnose an ABO incompatibility transfusion reaction, it can be used to diagnose infection, cancers, and inflammatory disease.

      Indirect Antiglobulin Test
      This test is an in vitro test for antibody-antigen reactions prior to blood transfusion. It can detect very low concentrations of antibodies in a patient’s plasma to ensure that donor blood will be compatible.

      Schirmer’s Test
      This test is used to diagnose keratoconjunctivitis sicca (dry eyes).

      White Cell Count
      Obtaining a white cell count is not a useful test in diagnosing an ABO incompatibility transfusion reaction. Although the patient may have fever and chills, it is likely secondary to a blood transfusion reaction rather than an acute infective process.

    • This question is part of the following fields:

      • Immunology
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  • Question 30 - A 50-year-old man comes to surgical outpatients complaining of recurrent abdominal pain and...

    Correct

    • A 50-year-old man comes to surgical outpatients complaining of recurrent abdominal pain and vomiting. During examination, a peripheral motor neuropathy is observed. What is the probable diagnosis?

      Your Answer: Acute intermittent porphyria

      Explanation:

      Unless proven otherwise, the presence of neurological symptoms along with abdominal pain may indicate either acute intermittent porphyria or lead poisoning.

      Understanding Acute Intermittent Porphyria

      Acute intermittent porphyria (AIP) is a rare genetic disorder that affects the biosynthesis of haem due to a defect in the porphobilinogen deaminase enzyme. This results in the accumulation of delta aminolaevulinic acid and porphobilinogen, leading to a range of symptoms. AIP typically presents in individuals aged 20-40 years, with females being more commonly affected.

      The condition is characterized by a combination of abdominal, neurological, and psychiatric symptoms. Abdominal symptoms include pain and vomiting, while neurological symptoms may manifest as motor neuropathy. Psychiatric symptoms may include depression. Hypertension and tachycardia are also common.

      Diagnosis of AIP involves a range of tests, including urine analysis, assay of red cells for porphobilinogen deaminase, and measurement of serum levels of delta aminolaevulinic acid and porphobilinogen. A classic sign of AIP is the deep red color of urine on standing.

      Management of AIP involves avoiding triggers and treating acute attacks with IV haematin/haem arginate. In cases where these treatments are not immediately available, IV glucose may be used. With proper management, individuals with AIP can lead healthy and fulfilling lives.

    • This question is part of the following fields:

      • Haematology And Oncology
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SESSION STATS - PERFORMANCE PER SPECIALTY

Haematology And Oncology (13/23) 57%
Immunology (5/7) 71%
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