Pediatric Hematology and Oncology
Core concepts
Understand the anemia approach - microcytic (iron deficiency, thalassemia), normocytic (hemolysis, chronic disease), macrocytic (B12/folate, marrow failure). Know the evaluation of bleeding and bruising (ITP, hemophilia, von Willebrand disease) and the interpretation of coagulation tests. Master the recognition of leukemia and lymphoma (pallor, bruising, hepatosplenomegaly, bone pain, mediastinal mass) and the approach to a child with a mass. Understand sickle cell disease and its complications.
Traps
Questions test whether you can distinguish iron deficiency from thalassemia trait using the Mentzer index and red cell distribution width. Another trap is attributing bruising to abuse without considering ITP or a coagulation disorder. Do not forget that a child with leukemia can present with musculoskeletal pain alone.
Worked example
A 4-year-old with pallor, petechiae, and hepatosplenomegaly has a blood count showing blasts; the next step is urgent referral to pediatric oncology and bone marrow evaluation. The trap is treating the anemia with iron before evaluating the smear.
Rule of thumb
Always examine the peripheral smear before treating anemia; it distinguishes iron deficiency, thalassemia, hemolysis, and marrow infiltration at a glance.