The direct Coombs test will specifically confirm immune-mediated haemolysis occurring post-transfusion in the aforementioned case.

There are two types of Coombs test used in immunohematology and immunology:

1. Direct Coombs test—It confirms autoimmune haemolytic anaemia by detecting antibodies or complement proteins attached to the surface of red blood cells.

2. Indirect Coombs test—It is used in prenatal testing of pregnant women and in testing prior to a blood transfusion. It detects antibodies floating freely in the blood, against foreign red blood cells.

The patient has Meigs syndrome. Meigs syndrome is defined as a triad of benign ovarian tumour with ascites and pleural effusion that resolves after resection of the tumour. Ovarian fibromas constitute the majority of the benign tumours seen in Meigs syndrome.

Tumour markers can be divided into:
1. Monoclonal antibodies
CA 125: Ovarian cancer, primary peritoneal cancer
CA 19-9: Pancreatic cancer
CA 15-3: Breast cancer

2. Tumour specific antigens
Prostate specific antigen (PSA): Prostatic carcinoma
Alpha-feto protein (AFP): Hepatocellular carcinoma, teratoma
Carcinoembryonic antigen (CEA): Colorectal cancer
S-100: Melanoma, schwannomas
Bombesin: Small cell lung carcinoma, gastric cancer

3. Enzymes
Alkaline phosphatase (ALP)
Neuron specific enolase (NSE)

4. Hormones
Calcitonin
Antidiuretic hormone (ADH)
Human chorionic gonadotropin (hCG)

Vitamin B12 is mostly used in the body for the development of red blood cells and maintenance of the nervous system. It is actively absorbed in the terminal ileum after binding to the intrinsic factor (IF) which is secreted from the parietal cells of stomach. Moreover, a small amount is also passively absorbed without being bound to IF.

Vitamin B12 deficiency is characterised by sore tongue and mouth, mood disturbances, ataxia, and macrocytic anaemia. Its causes include poor diet, impaired absorption (due to disorders of terminal ileum), pernicious anaemia, and post-gastrectomy. While managing this condition, if the person is also deficient in folic acid, then it is important to treat the B12 deficiency first in order to avoid precipitating subacute combined degeneration of the cord.

This is a typical picture of acute chest syndrome (ACS). According to the British Committee for Standards in Haematology (BCSH), ACS is defined as ‘an acute illness characterised by fever and/or respiratory symptoms, accompanied by a new pulmonary infiltrate on chest X-ray’. ACS occurs in sequestration crisis, which is one of the four main types of crises occurring in sickle cell disease.

The fundamentals of initial management are as follows:
1. Oxygen therapy to maintain saturation >95%
2. Intravenous fluids to ensure euvolemia
3. Adequate pain relief
4. Incentive spirometry in all patients presenting with rib or chest pain
5. Antibiotics with cover for atypical organisms
6. Bronchodilators if asthma co-exists with acute chest syndrome, or if there is an evidence of acute bronchospasm on auscultation
7. Early consultation with the critical care team and haematology department

A senior haematologist then makes a decision as to whether a simple or exchange transfusion is necessary in order to achieve a target Hb of 10.0–11.0g/dL in either instance.

Sickle Cell Crises:
Sickle cell anaemia is characterised by periods of good health with intervening crises:
1. Sequestration crisis: acute chest syndrome (i.e. fever, dyspnoea, chest/rib pain, low pO2, and pulmonary infiltrates)

2. Thrombotic (painful or vaso-occlusive) crisis: precipitated by infection, dehydration, and deoxygenation

3. Aplastic crisis: sudden fall in haemoglobin without marked reticulocytosis, usually occurring secondary to parvovirus infection

4. Haemolytic crisis: fall in haemoglobin secondary to haemolysis, rare type of sickle cell crises

A grossly elevated APTT may be caused by heparin therapy, haemophilia, or antiphospholipid syndrome. A normal factor VIIIc activity, however, points towards the diagnosis of haemophilia B, which is the deficiency of factor IX in the blood.

Haemophilia is an X-linked recessive disorder of coagulation. Up to 30% of patients have no family history of the condition. Haemophilia A is due to the deficiency of clotting factor VIII and is more common than haemophilia B, accounting for 90% of the cases. In haemophilia B (Christmas disease), there is a deficiency of clotting factor IX.

Characteristic features of haemophilia include hemarthrosis, haematomas, and prolonged bleeding following trauma or surgery. Coagulation profile of a haemophiliac person shows prolonged bleeding time, activated partial thromboplastin time (APTT), thrombin time (TT), but a normal prothrombin time (PT).

Monoclonal gammopathy of undetermined significance (MGUS)—also known as benign paraproteinemia and monoclonal gammopathy—is a pre-malignant condition not necessarily leading to its malignant form—multiple myeloma. MGUS causes increase of a serum monoclonal protein (M protein). It is not associated with ostealgia or increased risk of infections. It is often mistaken for multiple myeloma, differing from the latter in, no immunosuppression, anaemia, hypercalcaemia, lytic bone lesions, or renal failure; normal levels of beta-2 microglobulin; and stable lower levels of paraproteinemia.

Philadelphia translocation, t(9;22), is a marker of poor prognosis in acute lymphoblastic leukaemia (ALL).

ALL is the malignancy of lymphoid progenitor cells affecting B or T cell lineage. This results in the arrest of lymphoid cell maturation and proliferation of immature blast cells (lymphoblasts), leading to bone marrow and tissue infiltration.

ALL is the most common type of childhood cancers. Its peak incidence is between two to three years of age.

Acute B lymphoblastic leukaemia (B-ALL) is the most common type of ALL, involving overproduction of B-cell lymphoblasts. It is manifested by low initial WCC and is associated with a good prognosis.

Poor prognostic factors for ALL include:
1. Pre-B cell or T-cell ALL (T-ALL)
2. Philadelphia translocation, t(9;22)
3. Age <2 years or >10 years
4. Male sex
5. CNS involvement
6. High initial WBC (e.g. >100 x 10^9/L)
7. non-Caucasian

Poor prognostic factors for breast cancer include:
1. Young age (<40 years)
2. Premenopausal at the time of diagnosis
3. Increased tumour size
4. High-grade tumour
5. Oestrogen and progesterone receptor-negative tumour
6. Positive lymph node status

Bombesin is a tumour marker elevated in small cell lung carcinomas, as well as in gastric carcinomas and retinoblastomas.

Tumour markers can be divided into:
1. Monoclonal antibodies
CA 125: Ovarian cancer, primary peritoneal cancer
CA 19-9: Pancreatic cancer
CA 15-3: Breast cancer

2. Tumour specific antigens
Prostate specific antigen (PSA): Prostatic carcinoma
Alpha-feto protein (AFP): Hepatocellular carcinoma, teratoma
Carcinoembryonic antigen (CEA): Colorectal cancer
S-100: Melanoma, schwannomas
Bombesin: Small cell lung carcinoma, gastric cancer

3. Enzymes
Alkaline phosphatase (ALP)
Neuron specific enolase (NSE)

4. Hormones
Calcitonin
Antidiuretic hormone (ADH)
Human chorionic gonadotropin (hCG)

Prostate cancer is the most common primary tumour that metastasises to the bone.

Most common tumours causing bone metastasis (in descending order):
1. Prostate (32%)
2. Breast (22%)
3. Kidneys (16%)
4. Lungs
5. Thyroid

Most common sites of bone metastasis (in descending order):
1. Spine
2. Pelvis
3. Ribs
4. Skull
5. Long bones

Carcinoembryonic antigen (CEA) is a known tumour marker for colorectal cancer. It is not used diagnostically, but in patients with a known diagnosis of colorectal cancer associated with raised CEA levels, it can be used to monitor disease activity and help with the early identification of disease recurrence.

Tumour markers can be divided into:
1. Monoclonal antibodies
CA 125: Ovarian cancer, primary peritoneal cancer
CA 19-9: Pancreatic cancer
CA 15-3: Breast cancer

2. Tumour specific antigens
Prostate specific antigen (PSA): Prostatic carcinoma
Alpha-feto protein (AFP): Hepatocellular carcinoma, teratoma
Carcinoembryonic antigen (CEA): Colorectal cancer
S-100: Melanoma, schwannomas
Bombesin: Small cell lung carcinoma, gastric cancer

3. Enzymes
Alkaline phosphatase (ALP)
Neuron specific enolase (NSE)

4. Hormones
Calcitonin
Antidiuretic hormone (ADH)
Human chorionic gonadotropin (hCG)

Rasburicase should be given prior to chemotherapy in order to reduce the risk of tumour lysis syndrome (TLS). Rasburicase is a recombinant version of urate oxidase which is an enzyme that metabolizes uric acid to allantoin. Allantoin is 5–10 times more soluble than uric acid, hence, renal excretion is more effective.

TLS is a potentially fatal condition occurring as a complication during the treatment of high-grade lymphomas and leukaemias. It occurs from the simultaneous breakdown (lysis) of the tumour cells and subsequent release of chemicals into the bloodstream. This leads to hyperkalaemia and hyperphosphatemia in the presence of hyponatraemia. TLS can occur in the absence of chemotherapy, but it is usually triggered by the introduction of combination chemotherapy. Awareness of the condition is critical for its prophylactic management.

Burkitt lymphoma is a high-grade B-cell neoplasm. There are two major forms:
1. Endemic (African) form: typically involves maxilla or mandible.
2. Sporadic form: abdominal (e.g. ileocaecal) tumours are the most common form. More common in patients with HIV.

Burkitt lymphoma is associated with the c-myc gene translocation, usually t(8;14). The Epstein-Barr virus (EBV) is strongly implicated in development of the African form of Burkitt lymphoma and to a lesser extent, the sporadic form.

Management of the lymphoma is with chemotherapy. This tends to produce a rapid response which may cause TLS.

This is a picture of bone marrow failure secondary to acute myeloid leukaemia (AML). AML is the acute expansion of the myeloid stem line, which may occur as a primary disease or follow the secondary transformation of a myeloproliferative disorder. It is more common over the age of 45 and is characterized by signs and symptoms largely related to bone marrow failure such as anaemia (pallor, lethargy), frequent infections due to neutropenia (although the total leucocyte count may be very high), thrombocytopaenia (bleeding), ostealgia, and splenomegaly.

The disease has poor prognosis if:
1. Age of the patient >60 years
2. >20% blasts seen after the first course of chemotherapy
3. Chromosomal aberration with deletion of part of chromosome 5 or 7.

Acute promyelocytic leukaemia (APL) is an aggressive form of AML.

Other listed options are ruled out because:
1. Von Willebrand disease: may present with epistaxis and bleeding gums in severe cases but rarely with abnormalities on blood results.

2. Acute lymphoblastic leukaemia: mostly seen in children.

3. Lymphoma: usually presents with rubbery enlargement of lymph nodes.

4. Warfarin overdose: no bilobed large mononuclear cells seen on blood film.

Sickle cell anaemia is characterised by periods of good health with intervening crises. One of the main types is aplastic crisis characterised by a sudden fall in haemoglobin without marked reticulocytosis (3%—in this case—is just above the normal range). It usually occurs secondary to parvovirus infection.

The other main types of sickle cell crises are thrombotic crisis (painful or vaso-occlusive crisis), sequestration crisis, and haemolytic crisis. Thrombotic crisis is precipitated by infection, dehydration, alcohol, change in temperature, and deoxygenation. Sequestration crisis is characterised by acute chest syndrome (i.e. fever, dyspnoea, chest/rib pain, low pO2, and pulmonary infiltrates). In haemolytic crisis, fall in haemoglobin occurs secondary to haemolysis. It is a rare type of sickle cell crises.

Haemophilia B (Christmas disease), is the deficiency of clotting factor IX and is inherited in an X-linked recessive pattern. The factor IX level dictates the disease severity and established arthropathy is usually seen in those with severe disease.

The aforementioned patient’s history and presentation is consistent with the development of hemarthrosis. Joint aspiration is not recommended. The treatment, therefore, should be intravenous replacement of the deficient clotting factor with plasma-derived factor IX concentrate.

The other listed options are ruled out because:
1. Joint aspiration is not preferred over the administration of clotting factor as the first step of management.
2. DDAVP (desmopressin) can increase factor VIII levels transiently in those with mild haemophilia A and is useful prior to minor surgical procedures in such patients.
3. Cryoprecipitate is rich in fibrinogen, factor VIII, and von Willebrand factor and is used in the treatment of haemophilia A.

Hypogammaglobulinemia is a complication of chronic lymphocytic leukaemia (CLL) that leads to recurrent infections.

CLL is a type of cancer caused by monoclonal proliferation of well-differentiated lymphocytes, typically B cells (99%). Onset of the disease is usually asymptomatic and later constitutes anorexia, weight loss, bleeding, and recurrent infections. Lymphadenopathy is more marked in CLL than in chronic myelogenous leukaemia (CML).

Investigations to diagnose CLL include blood film and immunophenotyping. Smudge cells (also known as smear cells) seen on the blood film point towards CLL. Complications of the disease include hypogammaglobulinemia leading to recurrent infections, autoimmune haemolytic anaemia in 10–15% of the patients, and transformation to high-grade lymphoma (Richter’s transformation).

Immune thrombocytopenic purpura (ITP) refers to thrombocytopaenia occurring in the absence of toxic exposure or other diseases associated with low platelets and involves IgG-type antibodies. It is characterised by normal or increased marrow megakaryocytes, shortened platelet survival, and the absence of splenomegaly. Autoimmune haemolytic anaemia (AIHA) occurs commonly in association with ITP. Leukemic transformation, however, does not occur in ITP.

In neonatal ITP, IgG antibodies are passively transferred across the placenta. The infant platelet count may be normal at birth but decreases within 12–24 hours. It is rarely severe enough to induce bleeding diathesis in the infant.

Lead poisoning is characterised by abdominal pain, fatigue, constipation, peripheral neuropathy (mainly motor), and blue lines on gum margin in 20% of the adult patients (very rare in children).

For diagnosis, the level of lead in blood is usually considered with levels greater than 10 mcg/dL being significant. Furthermore, the blood film shows microcytic anaemia and basophilic stippling of red blood cells. Urinary coproporphyrin is increased (urinary porphobilinogen and uroporphyrin levels are normal to slightly increased). Raised serum and urine levels of delta-aminolaevulinic acid may also be seen, making it sometimes difficult to differentiate from acute intermittent porphyria.

All of the aforementioned options may be important however cytogenetics, for detecting chromosomal abnormalities, is the single most important test to determine her disease prognosis.

Acute myeloid leukaemia (AML) is the acute expansion of the myeloid stem line, which may occur as a primary disease or follow the secondary transformation of a myeloproliferative disorder. It is more common over the age of 45 and is characterized by signs and symptoms largely related to bone marrow failure such as anaemia (pallor, lethargy), frequent infections due to neutropenia (although the total leucocyte count may be very high), thrombocytopaenia (bleeding), ostealgia, and splenomegaly.

The disease has a poor prognosis if:
1. Age of the patient >60 years
2. >20% blasts seen after the first course of chemotherapy
3. Chromosomal aberration with deletion of part of chromosome 5 or 7.

Acute promyelocytic leukaemia (APL) is an aggressive form of AML.

This patient meets the diagnostic criteria for neutropenic sepsis, which is a relatively common complication of cancer therapy – usually chemotherapy occurring 7–14 days after. It is defined as a neutrophil count of <0.5 x 10^9/L in a patient undergoing anticancer treatment and who has either a temperature higher than 38°C or has other features consistent with clinically significant sepsis. Management approach is the same as mentioned in this case. However, if the patient still remains unwell, then an antifungal such as amphotericin B is started after risk-stratifying the patient and carrying out investigations (e.g. HRCT and Aspergillus PCR) to determine the likelihood of systemic fungal infection.

The patient has spinal cord compression until proven otherwise. Urgent assessment is required.

Spinal cord compression is an oncological emergency and affects up to 5% of cancer patients. Extradural compression accounts for the majority of cases, usually due to vertebral body metastases. One of the most common causes of spinal cord compression is osteoarthritis. It is also more commonly seen in patients with lung, breast, or prostate cancer.

Clinical features include:
1. Back pain: the earliest and most common symptom, may worsen on lying down or coughing
2. Lower limb weakness
3. Sensory changes: sensory loss and numbness
4. Neurological signs: depending on the level of the lesion.
Lesions above L1 usually result in upper motor neurone signs in the legs. Lesions below L1 usually cause lower motor neurone signs in the legs and perianal numbness. Tendon reflexes are increased below the level of the lesion and absent at the level of the lesion.

Management options are:
1. High-dose oral dexamethasone
2. Urgent MRI for consideration of radiotherapy or surgery

There are two main reasons for using combinations of chemotherapeutic agents rather than single agents. First, different drugs exert their effects through different mechanisms, therefore, carefully combining them will increase the number of tumour cells killed in each cycle as well as decrease their chances of developing drug resistance. Second, there may be an even greater effect with drugs that are synergistic.

An MRI whole spine should be performed in a patient suspected of spinal metastasis which can occur before developing metastatic spinal cord compression. This patient has renal cell carcinoma, which readily metastasises to the bones and also has progressive back pain. He, therefore, needs urgent imaging of his spine before any neurological compromise develops. MRI whole spine is preferable because patients with spinal metastasis often have metastases at multiple levels within the spine. Plain radiographs and CT scans should not be performed as they have a lower sensitivity for revealing lesions and cannot exclude cord compression.

In general, imaging should be performed within one week if symptoms suspicious of spinal metastasis without neurological symptoms are present. If there are symptoms suggestive of malignant spinal cord compression, then imaging should be done within 24 hours.

The signs and symptoms of spinal metastases include:
1. Unrelenting lumbar back pain
2. Thoracic or cervical back pain
3. Pain associated with tenderness and worsens with sneezing, coughing, or straining
4. Nocturnal pain

Aprepitant is an anti-emetic which blocks the neurokinin 1 (NK1) receptor and acts as a substance P antagonist. It is licensed for chemotherapy-induced nausea and vomiting (CINV) and for prevention of postoperative nausea and vomiting.

Nausea and vomiting are the common side effects of chemotherapy. Risk factors for the development of these symptoms include age<50 years, anxiety, concurrent use of opioids, and the type of chemotherapy administered.

Cisplatin is a cytotoxic agent that acts by causing cross-linking in DNA. Its adverse effects include ototoxicity, peripheral neuropathy, hypomagnesaemia, etc.

The causative cytotoxic agents acting through the other aforementioned MOAs are as follows:

1. Doxorubicin: Stabilizes DNA topoisomerase II complex and inhibits DNA and RNA synthesis.

2. Hydroxyurea (hydroxycarbamide): Inhibits ribonucleotide reductase, decreasing DNA synthesis.

3. Mercaptopurine (6-MP): Purine analogue that is activated by HGPRTase, decreasing purine synthesis.

4. Vincristine, vinblastine: Inhibits formation of microtubules.

A translocation between chromosome 15 and 17 is seen in acute promyelocytic leukaemia (APL), which is known to carry a good prognosis.

Acute myeloid leukaemia (AML) is the acute expansion of the myeloid stem line, which may occur as a primary disease or follow the secondary transformation of a myeloproliferative disorder. It is more common over the age of 45 and is characterized by signs and symptoms largely related to bone marrow failure such as anaemia (pallor, lethargy), frequent infections due to neutropenia (although the total leucocyte count may be very high), thrombocytopaenia (bleeding), ostealgia, and splenomegaly. The disease has poor prognosis if:

The disease has poor prognosis if:
1. Age of the patient >60 years
2. >20% blasts seen after the first course of chemotherapy
3. Chromosomal aberration with deletion of part of chromosome 5 or 7.

APL is an aggressive form of AML. It is associated with t(15;17) and has a good prognosis. The general age of presentation is less than that in other types of AML (average age is 25 years old). On blood film, abundant Auer rods are seen with myeloperoxidase staining. Thrombocytopaenia or DIC is seen in patients presenting with this disease.

Involvement of lymph nodes on both sides of the diaphragm accompanied by night sweats would be staged as IIIB according to the Ann Arbor staging system for Hodgkin lymphoma (HL).

HL is a malignant proliferation of lymphocytes characterised by the presence of distinctive giant cells known as Reed-Sternberg cells. It has a bimodal age distribution being most common in the third and seventh decades of life.

Staging of HL is done according to the Ann Arbor staging system:
Stage
I: Single lymph node region (I) or one extra lymphatic site (IE)

II: Two or more lymph node regions on same side of the diaphragm (II) or local extra lymphatic extension plus one or more lymph node regions on same side of the diaphragm (IIE)

III: Lymph node regions on both sides of the diaphragm (III) which may be accompanied by local extra lymphatic extension (IIIE)

IV: Diffuse involvement of one or more extra lymphatic organs or sites

Suffix
A: No B symptoms

B: Presence of at least one of the following: unexplained weight loss >10% baseline during 6 months before staging; recurrent unexplained fever >38°C; recurrent night sweats—poor prognosis.

Subcutaneous (S/C) low-molecular-weight heparin (LMWH) is a preferred anticoagulant in pregnancy. Warfarin is contraindicated due to its teratogenic effects, especially in the first trimester and at term.

Pregnancy is a hypercoagulable state with the majority of VTE incidents occurring in the last trimester.

Hypercoagulability in pregnancy is caused by:
1. Increase in factors VII, VIII, X, and fibrinogen
2. Decrease in protein S
3. Uterus pressing on IVC causing venous stasis in legs

Management options include:
1. S/C LMWH preferred to IV heparin (less bleeding and thrombocytopaenia)
2. Warfarin contraindicated

Thalassaemias are a group of genetic disorders characterised by decreased production of either alpha or beta chains of haemoglobin (Hb). Beta thalassaemia trait is an autosomal recessive condition in which a disproportionate hypochromic, microcytic anaemia occurs—microcytosis is disproportionate to the Hb level. It is usually asymptomatic.

Microcytic anaemia in a female should raise the possibility of either gastrointestinal blood loss or menorrhagia. However, there is no history to suggest this in the aforementioned patient. This, combined with characteristic disproportionate microcytosis and raised HbA2 levels ( >3.5%), point towards beta thalassaemia trait.

Basophilic stippling is also seen in lead poisoning but the raised HbA2 levels cannot be explained in such a case.

Normal pO2 but decreased oxygen saturation is characteristic of methemoglobinemia.

Methemoglobinemia is a rare condition in which the haemoglobin iron is in oxidized or ferric state (Fe3+) and cannot reversibly bind oxygen. Normally, the conversion of ferrous form of iron (Fe2+) to its ferric form (Fe3+) is regulated by NADH methaemoglobin reductase, which results in the reduction of methaemoglobin to haemoglobin. Disruption in the enzyme leads to increased methaemoglobin in the blood. There is tissue hypoxia as Fe3+ cannot bind oxygen, and hence the oxygen-haemoglobin dissociation curve is shifted to the left.

Methemoglobinemia can occur due to congenital or acquired causes. Congenital causes include haemoglobin variants such as HbM and HbH, and deficiency of NADH methaemoglobin reductase. Acquired causes are drugs (e.g. sulphonamides, nitrates, dapsone, sodium nitroprusside, and primaquine) and chemicals (such as aniline dyes).

The features of methemoglobinemia are cyanosis, dyspnoea, anxiety, headache, severe acidosis, arrhythmias, seizures, and loss of consciousness. Patients have normal pO2 but oxygen saturation is decreased. Moreover, presence of chocolate-brown coloured arterial blood (colour does not change with addition of O2) and brown urine also point towards the diagnosis of methemoglobinemia.