Haematology and Oncology
Core framework
Divide into anaemia, cytopenias, coagulopathy, haematological malignancy, and solid tumour emergencies. For anaemia, classify by mean corpuscular volume and reticulocyte response; for cytopenias, ask whether the marrow is failing, the periphery is destroying, or sequestration is occurring. In oncology, know the oncological emergencies and their immediate management, and understand that staging and performance status drive treatment intent.
Concepts examiners test
Microcytic anaemia workup (iron studies, thalassaemia trait, anaemia of chronic disease); megaloblastic anaemia and B12 deficiency neurological risk; haemolytic anaemia with direct antiglobulin testing; the diagnostic pathway for suspected myeloma (serum free light chains, electrophoresis, bone marrow); lymphoma presentation and staging; leukaemia emergencies (leucostasis, tumour lysis syndrome); heparin-induced thrombocytopenia; and the coagulopathies (haemophilia, von Willebrand disease, disseminated intravascular coagulation).
Traps
- Do not give folate alone in B12 deficiency - it can precipitate subacute combined degeneration.
- Tumour lysis syndrome needs prophylaxis in high-risk disease; watch potassium, phosphate, urate and calcium.
- Neutropenic sepsis is a time-critical emergency; antibiotics within one hour without waiting for cultures.
- Heparin-induced thrombocytopenia is prothrombotic - stop heparin and use a non-heparin anticoagulant, not platelet transfusion.
- Iron deficiency in an adult male or postmenopausal woman demands gastrointestinal investigation.
Worked rule of thumb
A febrile patient with neutropenia after chemotherapy: take blood cultures and lactate, then give broad-spectrum antipseudomonal antibiotics within one hour. Do not wait for imaging or culture results; escalate for hypotension or organ dysfunction.