Pediatric Hematology and Oncology
Hematology items test systematic anaemia classification with the reticulocyte count and red cell indices, recognition of haemolytic disease, and safe management of bleeding disorders. Oncology items test early recognition of common childhood tumours and emergency management of febrile neutropenia and tumour lysis.
Anaemia
- Microcytic: iron deficiency shows low ferritin, high red cell distribution width and a Mentzer index below 13; thalassaemia shows normal ferritin, target cells and raised HbA2.
- Give elemental iron 3-6 mg/kg/day; expect reticulocytosis within a week and a haemoglobin rise of about 1 g/dL in 2-4 weeks.
- Normocytic with high reticulocytes suggests haemolysis: request direct Coombs, G6PD assay, lactate dehydrogenase, haptoglobin and haemoglobin electrophoresis.
Sickle cell disease
- Penicillin prophylaxis from 4 months, plus pneumococcal and Haemophilus vaccination.
- Hydroxyurea reduces crises; transcranial Doppler screening detects stroke risk.
- Acute chest syndrome: fever, chest pain, hypoxia and new infiltrate; give oxygen, antibiotics, incentive spirometry and transfusion.
Bleeding disorders
- Immune thrombocytopenia: isolated thrombocytopenia in a well child with no lymphadenopathy; observe, or use IVIG or anti-D. Avoid aspirin and intramuscular injections.
- Haemophilia: prolonged aPTT with normal prothrombin time; replace factor VIII or IX; desmopressin works in mild haemophilia A.
Oncology
- Acute lymphoblastic leukaemia is the commonest childhood malignancy, peaking at 2-5 years; cure requires risk-stratified chemotherapy with intrathecal prophylaxis.
- Febrile neutropenia: give an anti-pseudomonal beta-lactam within 60 minutes of presentation.
- Tumour lysis syndrome: hyperkalaemia, hyperphosphataemia, hyperuricaemia and hypocalcaemia; hydrate and give allopurinol or rasburicase.
- Wilms tumour peaks at 3-4 years and presents as an abdominal mass; management is nephrectomy plus chemotherapy.
Worked example
A 3-year-old with pallor has haemoglobin 6.5 g/dL, MCV 62 fL, ferritin 4 ng/mL and platelets 450,000. This is iron deficiency anaemia with reactive thrombocytosis. Ask about cow's milk intake and blood loss, start oral iron with vitamin C, and recheck in four weeks; failure to respond means the diagnosis or the adherence is wrong, or there is ongoing loss.
Traps
Transfusing iron-deficient children who are stable, missing thalassaemia trait in a child with mild microcytosis and a normal ferritin, and delaying antibiotics in febrile neutropenia.