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).

The patient is most likely a case of haemophilia A which is the genetic deficiency of clotting factor VIII in 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 more common than haemophilia B and accounts 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).

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.

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.

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.

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.

Out of the aforementioned markers, low corrected calcium is the only biochemistry result consistent with the diagnosis. All of the other markers are elevated in TLS.

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. As phosphate precipitates calcium, the serum concentration of calcium becomes low. 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.

Patients at high risk of TLS should be given IV rasburicase or IV allopurinol immediately prior to and during the first few days of chemotherapy. Rasburicase is a recombinant version of urate oxidase which is an enzyme that metabolizes uric acid to allantoin. Allantoin is much more water soluble than uric acid and is therefore more easily excreted by the kidneys. Patients in lower-risk groups
should be given oral allopurinol during cycles of chemotherapy in an attempt to avoid the condition.

TLS is graded according to the Cairo-Bishop scoring system as:
1. Laboratory tumour lysis syndrome
2. Clinical tumour lysis syndrome

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.

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).

Liver cirrhosis is not associated with hyposplenism.

Hyposplenism is caused by a variety of conditions. These are:
1. Splenectomy
2. Sickle cell anaemia
3. Coeliac disease, dermatitis herpetiformis
4. Graves’ disease
5. Systemic lupus erythematosus (SLE)