Tumour marker CA 125 is mostly associated with primary peritoneal cancer and ovarian cancer. It can be used to monitor response to chemotherapy, alongside regular CT scans.

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)

This patient is a case of chronic myeloid leukaemia (CML) and should be started on imatinib as the first-line drug of choice.

The patient could respond well to palliative radiotherapy. This course of action is likely to shrink the cancer and will, therefore, reduce the pain felt. Analgesics should then be used to control the symptoms.

Warfarin inhibits the vitamin K-dependent procoagulants II, VII, IX, and X as well as anticoagulant protein C and S. It is highly protein-bound and can be displaced by a wide variety of drugs. It has a half-life of 36-48 hours.

Bleeding is the major side effect. Easy bruising, as seen in this case, is commonly seen in patients of warfarin overdose. Grossly prolonged PT and lesser increase in APTT may be seen in such cases.

An increase in the patient’s haemoglobin tells us that the patient might be having an increased number of red blood cells. Smoking causes raised carboxyhaemoglobin levels and thus hypoxemia. Hypoxemia will increase the erythropoietin levels in the blood.

The most likely diagnosis with anaemia, raised erythrocyte sedimentation rate (ESR), hypercalcaemia, renal impairment, and raised total protein with low albumin is multiple myeloma (MM). Protein electrophoresis will confirm the presence of monoclonal band of paraprotein. Of note, a radioisotope bone scan is not a good test for picking up the lytic lesions of MM.

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

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.

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.

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

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.

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).

The likely diagnosis in this case is Haemolytic Uremic Syndrome (HUS), which is generally seen in young children presenting with a triad of symptoms, namely: acute renal failure, microangiopathic haemolytic anaemia, and thrombocytopenia. The typical cause of HUS is ingestion of a strain of Escherichia coli. The laboratory results will usually include fragmented RBCs, decreased serum haptoglobin, reduced platelet count, nonspecific WBC changes, and normal coagulation tests (PTT included).

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.

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

The diagnosis of Hodgkin disease requires the identification of Reed-Sternberg cells in a characteristic cellular background. The normal cell of origin for the Reed-Sternberg cells remains unclear, with the predominance of evidence indicating a B or T lymphocyte.

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.

The patient has acute promyelocytic leukaemia (APML) with associated disseminated intravascular coagulation (DIC). Although the platelet count is high, platelet function is ineffective.

Patients may present, as in this case, with severe bleeding, and the most appropriate emergency treatment would be administration of fresh frozen plasma (FFP).

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.

The patient has paroxysmal nocturnal haemoglobinuria (PNH). The classic sign of the disease is red discolouration of the urine due to the presence of haemoglobin and hemosiderin from the breakdown of red blood cells. As the urine is more concentrated in the morning, this is when the colour is most pronounced.

PNH is an acquired clonal disorder of haematopoietic stem cells, characterised by variable combinations 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.

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

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. For patients at low risk of these symptoms, drugs such as metoclopramide may be used. For high-risk patients, however, 5-HT3 receptor antagonists such as ondansetron are often effective, especially if combined with dexamethasone.

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.

The major delayed problem with radiotherapy is the development of secondary cancers. This risk begins to appear ten years after therapy.

The upper motor neurone signs in this patient point towards a diagnosis of spinal cord compression above the level of L1 and rules out cauda equina syndrome.

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

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.

Gamma delta T cells are of low abundance in the body, are found in the gut mucosa, skin, lungs and uterus, and are involved in the initiation and propagation of immune responses. Their ligands are not known in detail, but the gamma delta T cell receptors recognise intact proteins rather than MHC-presented peptides. Like alpha beta T cells, they develop in the thymus.

This is a case of Vit. B12 or folic acid deficiency. The anaemia with angular stomatitis is highly suggestive of Vit. B12 or folate deficiency. The absence of koilonychia excludes Iron deficiency anaemia.