Hematology and Oncology
Core concepts
Anemia classification by MCV, iron studies, B12 and folate, hemolysis markers, coagulopathy, thrombocytopenia, leukemia and lymphoma presentations, oncologic emergencies, and transfusion medicine. Microcytic anemia with low ferritin means iron deficiency; anemia of chronic disease shows low iron, low TIBC, and normal or high ferritin. Macrocytic anemia with neurologic findings suggests B12 deficiency; check methylmalonic acid when borderline. Febrile neutropenia is an emergency requiring empiric antipseudomonal coverage within 60 minutes.
Traps
- Giving platelets in TTP; plasma exchange is the treatment.
- Continuing heparin in heparin-induced thrombocytopenia; stop heparin and use a non-heparin anticoagulant.
- Missing tumor lysis syndrome before chemotherapy in bulky lymphoma.
- Confusing DIC (prolonged PT and PTT, low fibrinogen, high D-dimer, schistocytes) with ITP.
- Transfusing to a hemoglobin target without symptoms.
- Forgetting that hypercalcemia of malignancy can cause shortened QT and confusion.
Worked example
A 68-year-old with fatigue has hemoglobin 8.2, MCV 72, ferritin 8, and iron saturation 8%. This is iron deficiency. The next step is not simply oral iron but identifying the source, especially gastrointestinal blood loss in older adults. Rule of thumb: iron deficiency in a man or postmenopausal woman is a GI question until proven otherwise.