Polycythaemia vera (PV) is associated with a low ESR.

PV, also known as polycythaemia rubra vera, is a myeloproliferative disorder caused by clonal proliferation of marrow stem cells leading to an increase in red cell volume, often accompanied by overproduction of neutrophils and platelets. It has peak incidence in the sixth decade of life, with typical features including hyperviscosity, pruritus, splenomegaly, haemorrhage (secondary to abnormal platelet function), and plethoric appearance. PV is associated with a low ESR.

Some management options of PV include lose-dose aspirin, venesection (first-line treatment), hydroxyurea (slightly increased risk of secondary leukaemia), and radioactive phosphorus (P-32) therapy.

In PV, thrombotic events are a significant cause of morbidity and mortality. 5–15% of the cases progress to myelofibrosis or acute myeloid leukaemia (AML). The risk of having AML is increased with chemotherapy treatment.

Mycoplasma infection causes cold autoimmune haemolytic anaemia (AIHA). The rest of the aforementioned options cause warm AIHA.

AIHA may be divided into ‘warm’ and ‘cold’ types, according to the temperature at which the antibodies best cause haemolysis. It is most commonly idiopathic but may be secondary to a lymphoproliferative disorder, infection, or drugs.

1. Warm AIHA:
In warm AIHA, the antibody (usually IgG) causes haemolysis best at body temperature and tends to occur in extravascular sites, for example, spleen. Management options include steroids, immunosuppression, and splenectomy. It is caused by autoimmune diseases such as SLE (rarely causes mixed-type AIHA), cancers such as lymphomas and CLL, and drugs such as methyldopa.

2. Cold AIHA:
The antibody in cold AIHA is usually IgM and causes haemolysis best at 4°C and occurs more commonly intravascularly. Features may include symptoms of Raynaud’s disease and acrocyanosis. Patients do not respond well to steroids. Cold AIHA is caused by cancers such as lymphomas, and infections such as mycoplasma and EBV.

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.

St John’s wort interferes with warfarin by increasing its breakdown and decreasing its effectiveness. This leads to the need for adjustment in the dose of warfarin and careful attention to monitoring if the patient decides to continue with the drug. Ideally, an alternative antidepressant should also be considered.

Night sweats are a B symptom in Hodgkin lymphoma (HL) and imply a poor prognosis.

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.

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

This patient is having vaso-occlusive event/crisis (thrombotic crisis) which is a type of sickle cell crisis. It may be associated with ostealgia.

There is no evidence of an aplastic crisis in this case as the haemoglobin level is reasonable with a good reticulocyte count. Conversely, the haemoglobin is not low enough and reticulocyte count and bilirubin are not high enough for a haemolytic crisis.

Sickle cell anaemia is characterised by periods of good health with intervening crises. The four main types of sickle cell crises are thrombotic crisis (painful or vaso-occlusive crisis), sequestration crisis, aplastic 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). Aplastic crisis is characterised by a sudden fall in haemoglobin without marked reticulocytosis. It usually occurs secondary to parvovirus infection. In haemolytic crisis, a fall in haemoglobin occurs secondary to haemolysis. It is a rare type of sickle cell crisis.

Good prognosis of chronic lymphocytic leukaemia (CLL) is associated with deletion of the long arm of chromosome 13 (del 13q). This is the most common abnormality, seen in around 50% of all CLL patients. Poor prognosis of the disease is related to deletion of part of the short arm of chromosome 17 (del 17p). This is seen in around 5-10% of the patients suffering from CLL.

Poor prognostic factors of CLL include:
1. Male sex
2. Age >70 years
3. Lymphocyte count >50
4. Prolymphocytes comprising more than 10% of blood lymphocytes
5. Lymphocyte doubling time <12 months
6. Raised LDH
7. CD38 expression positive

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

CXR, blood, and urine tests should be carried out initially to exclude an underlying malignancy. If these are normal, a CT scan of abdomen and pelvis should be arranged as the patient’s age is >40 years. Antiphospholipid antibodies should also be checked for the first unprovoked DVT/PE. There is no history, however, to support an inherited thrombophilia.

The National Institute for Health and Care Excellence (NICE) published guidelines in 2012 for the investigation and management of DVT. If a patient is suspected of having DVT, a two-level DVT Wells score should be used:

DVT likely: 2 points or more
DVT unlikely: 1 point or less

This system of points is based on the following clinical features:
1. Active cancer (treatment ongoing, within six months, or palliative)—1
2. Paralysis, paresis, or recent plaster immobilisation of the lower extremities—1
3. Recently bedridden for three days or more, or major surgery within 12 weeks requiring general or regional anaesthesia—1
4. Localised tenderness along the distribution of the deep venous system—1
5. Entire leg swollen—1
6. Calf swelling at least three cms larger than the asymptomatic side—1
7. Pitting oedema confined to the symptomatic leg—1
8. Collateral superficial veins (non-varicose)—1
9. Previously documented DVT—1
10. An alternative diagnosis is at least as likely as DVT—2

If two points or more—DVT is ‘likely’
If one point or less—DVT is ‘unlikely’

Management

1. LMWH or fondaparinux should be given initially after a DVT is diagnosed.
2. A vitamin K antagonist such as warfarin should be given within 24 hours of the diagnosis.
3. LMWH or fondaparinux should be continued for at least five days or until the international normalised ratio (INR) is 2.0 or above for at least 24 hours. LMWH or fondaparinux is given at the same time as warfarin until the INR is in the therapeutic range.
4. Warfarin should be continued for at least three months. At three months, clinicians should assess the risks and benefits of extending the treatment.
5. Consider extending warfarin beyond three months for patients with unprovoked proximal DVT if their risk of VTE recurrence is high and there is no additional risk of major bleeding. This essentially means that if there is no obvious cause or provoking factor (surgery, trauma, significant immobility, etc.), it may be implied that the patient has a tendency to thrombose and should be given treatment longer than the normal of three months. In practice, most clinicians give six months of warfarin for patients with an unprovoked DVT/PE.
6. For patients with active cancer, LMWH should be used for six months.

As both malignancy and thrombophilia are obvious risk factors for DVT, therefore, all patients with unprovoked DVT/PE who are not already known to have cancer should undergo the following investigations:
1. Physical examination (guided by the patient’s full history)
2. Chest X-ray
3. Blood tests (full blood count, serum calcium, and liver function tests) and urinalysis
4. Testing for antiphospholipid antibodies
5. Testing for hereditary thrombophilia in patients who have had unprovoked DVT/PE and have a first-degree relative who has a history of DVT/PE.

The patient is displaying signs and symptoms of hyperviscosity syndrome, secondary to the Waldenström’s macroglobulinemia. Treatment of choice is plasmapheresis.

Waldenström’s macroglobulinemia (also called lymphoplasmacytic lymphoma) is an uncommon type of non-Hodgkin lymphoma seen in older people. It is a lymphoplasmacytoid malignancy characterised by the secretion of a monoclonal IgM paraprotein. Its features include monoclonal IgM paraproteinemia; hyperviscosity syndrome leading to bilateral central retinal vein occlusion (CRVO) and hence, visual disturbances; weight loss and lethargy; hepatosplenomegaly and lymphadenopathy; and cryoglobulinemia. It is not, however, associated with bone pain.

The patient has paroxysmal nocturnal haemoglobinuria (PNH) complicated by acute hepatic vein thrombosis (Budd–Chiari syndrome).

PNH is an acquired clonal disorder of haematopoietic stem cells, characterised by variable combination of intravascular haemolysis, thrombosis, and bone marrow failure. Diagnosis is made by flow cytometric evaluation of blood, which confirms the CD55 and CD59 deficiencies and deficiency of expression of other GPI-linked proteins. This test is replacing older complement-based assays such as the Ham test and sucrose lysis test.

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.

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.

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.

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.

Exposure to aniline dyes is a risk factor for transitional cell carcinoma. Aniline dyes are used in dyestuffs and pigment manufacturing.

The other aforementioned options are ruled out because:
1. Feed production may expose to aflatoxin (hepatocellular carcinoma).

2. Being a military personnel may expose to mustard gas (lung cancer).

3. Rubber industry may expose to nitrosamines (oesophageal and gastric cancer).

4. Refrigerant production before 1974 may expose to vinyl chloride (hepatic angiosarcoma).

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.

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.

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).

Hb S is the most common type of abnormal haemoglobin and the basis of sickle cell trait and sickle cell anaemia. It differs from normal adult haemoglobin (called haemoglobin A—Hb A) only by a single amino acid substitution due to point mutation—a valine replacing a glutamine in the sixth position of the beta chain of globin. Hb S molecules polymerize in hypoxic and acidic environments, imparting a sickle shape to the RBCs. Hb S molecules are less negatively charged than Hb A (due to the loss of glutamine) and have a lower affinity for oxygen (right shift of the oxygen-dissociation curve).

Superior vena cava (SVC) obstruction is an oncological emergency caused by compression of the SVC and is most commonly associated with lung cancer.

Some causes of the condition include:
1. Common malignancies: non small cell lung cancer, lymphoma
2. Other malignancies: metastatic seminoma, Kaposi’s sarcoma, breast cancer
3. Aortic aneurysm
4. Mediastinal fibrosis

Clinical features of SVC obstruction include:
1. Dyspnoea: most common
2. Swelling of the face, neck, and arms: conjunctival and periorbital oedema may be seen
3. Headache: often worse in the morning
4. Visual disturbances
5. Pulseless jugular venous distension

Management options are:
1. General: dexamethasone, balloon venoplasty, stenting
2. Small cell lung cancer: chemotherapy and radiotherapy
3. Non small cell lung cancer: radiotherapy

Urinary porphobilinogen is increased between attacks of acute intermittent porphyria (AIP) and even more so, between acute attacks.

AIP is a rare autosomal dominant condition caused by a defect in porphobilinogen deaminase, an enzyme involved in the biosynthesis of haem. This results in the toxic accumulation of delta-aminolaevulinic acid and porphobilinogen.

Abdominal and neuropsychiatric symptoms are characteristic of AIP especially in people between the ages of 20–40 years. The disease is more common in females than in males (5:1). Major signs and symptoms of AIP include abdominal pain, vomiting, motor neuropathy, hypertension, tachycardia, and depression.

Diagnosis:
1. Urine turns deep red on standing (classical picture of AIP)
2. Raised urinary porphobilinogen (elevated between attacks and to a greater extent, between acute attacks)
3. Raised serum levels of delta-aminolaevulinic acid and porphobilinogen
4. Assay of red blood cells for porphobilinogen deaminase

The diagnosis for the aforementioned case is thrombotic thrombocytopenic purpura (TTP). TTP is classically characterised as a pentad of thrombocytopaenia, microvascular haemolysis, fluctuating neurological signs, renal impairment, and fever.

The differential diagnosis for severe thrombocytopaenia is immune thrombocytopenic purpura (ITP). ITP is more common than TTP. However, a patient of ITP would not present with the range of symptoms seen in this scenario.

In TTP, there is deficiency of a protease which breaks down large multimers of von Willebrand factor. This leads to abnormally large and sticky multimers of von Willebrand factor which cause platelets to clump within the vessels.

Untreated TTP has a mortality rate of up to 90%. Therefore, rapid plasma exchange (PEX) may be a life-saving intervention. Platelet transfusion in TTP is only indicated if there is an ongoing life-threatening bleed. Intravenous methylprednisolone is indicated after treatment with PEX has been completed. There is no current role of intravenous immunoglobulin in the routine management of TTP. However, there have been reports of its successful use in PEX- and steroid-refractory cases. Intravenous argatroban is indicated in heparin-induced thrombocytopaenia (HIT), but there is no history of recent heparin administration or hospitalisation in this patient nor are the clinical signs consistent with HIT.

Management options for TTP include PEX as the treatment of choice. Steroids and immunosuppressants are also given. Antibiotics are not recommended as they may worsen the outcome of the disease. For cases resistant to PEX and pharmacologic therapy, vincristine is given.

Cyclophosphamide is a cytotoxic alkylating agent that acts by causing cross-linking of DNA strands. Its major adverse effects include haemorrhagic cystitis, myelosuppression, and transitional cell carcinoma.

Cardiomyopathy is caused by doxorubicin and ototoxicity is caused by cisplatin. Alopecia and weight gain are associated with a variety of chemotherapeutic agents especially those that treat breast cancers (e.g. paclitaxel).

All of the aforementioned listed tumours, except brain tumours, can metastasise to lungs and produce the typical CXR picture consisting of hilar lymphadenopathy with either diffuse multinodular shadows resembling miliary disease or multiple large well-defined masses (canon balls). Occasionally, cavitation or calcification may also be seen.

Most brain tumours, however, do not metastasise. Some, derived form neural elements, do so but in these cases, intraparenchymal metastases generally precede distant haematogenous spread.

This is a classical picture of graft versus host disease (GVHD) following bone marrow transplant. Acute GVHD occurs in the first 100 days post transplant with chronic GVHD occurring 100-300 days after transplant. GVHD is graded according to the Seattle system, and each organ involved is scored (skin, liver, and gut).

The standard initial treatment in the acute setting is high-dose methylprednisolone started immediately. If there is no response, a more intensive immunosuppressive agent such as alemtuzumab or antilymphocyte globulin is needed.

Of all the listed options, gastric cancer is least likely to be inherited.

The above mentioned tumours are ruled out as explained below:
1. Breast and Ovarian cancers: Between 5%–10% of all breast cancers are thought to be hereditary. Mutation in the BRCA1 and BRCA2 genes also increase the risk of ovarian cancer.

2. Colorectal and Endometrial cancers: About 5% of cases of colorectal cancer are caused by hereditary non-polyposis colorectal carcinoma (HNPCC) and 1% are due to familial adenomatous polyposis. Women who have HNPCC also have a markedly increased risk of developing endometrial cancer—around 5% of endometrial cancers occur in women with this risk factor.

The patient is asymptomatic but matches the diagnostic criteria for multiple myeloma (MM). Therefore, the underlying diagnosis of this condition is smouldering multiple myeloma (SMM). SMM is an early precursor to MM. Its treatment is typically to watch and wait.

MM is a neoplasm of the bone marrow plasma cells. Peak incidence is in patients aged 60–70 years.

Clinical features of MM include:
1. Ostealgia, osteoporosis, pathological fractures (typically vertebral), and osteolytic lesions
2. Lethargy
3. Infections
4. Hypercalcaemia
5. Renal failure
6. Other features: amyloidosis e.g. macroglossia, carpal tunnel syndrome; neuropathy; hyperviscosity

Diagnosis of MM is based on the confirmation of (a) one major criterion and one minor criterion or (b) three minor criteria in an individual who has signs or symptoms of multiple myeloma.

Major criteria:
1. >30% plasma cells on bone marrow biopsy
2. Monoclonal band of paraprotein on electrophoresis: >35g/L for IgG, 20g/L for IgA, or >1g of light chains excreted in the urine per day

Minor criteria:
1. 10–30% plasma cells on bone marrow biopsy
2. Abnormal monoclonal band but levels less than listed above
3. Lytic bone lesions observed radiographically
4. Immunosuppression

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