Hematologic Malignancies and Hematopoietic Stem Cell Transplantation
What this domain tests
Hematology items test diagnosis-linked urgent treatment, response-adapted therapy, molecular monitoring in chronic leukemias, and the indications, types and complications of stem cell transplantation.
Core rules
- Acute promyelocytic leukemia with t(15;17)/PML-RARA is an emergency: start all-trans retinoic acid on suspicion, before confirmation, plus arsenic trioxide in low/intermediate risk, and support coagulopathy aggressively. Avoid unnecessary invasive procedures; leukapheresis is not indicated.
- AML induction is anthracycline plus cytarabine (7+3), stratified by ELN cytogenetic and molecular risk; FLT3 inhibitors (midostaurin, gilteritinib), IDH inhibitors and gemtuzumab ozogamicin are genotype-directed.
- CML: TKI therapy with BCR-ABL1 milestones - ≤10% at 3 months, ≤1% at 12 months. Progression to blast crisis is managed with a different-generation TKI plus transplant consideration.
- DLBCL: R-CHOP, with cell-of-origin and FISH for MYC/BCL2/BCL6 rearrangements; double-hit disease and relapsed disease are considered for CAR-T or transplant. Polatuzumab vedotin plus R-CHP is an alternative first line.
- Hodgkin lymphoma: ABVD with PET-adapted escalation or de-escalation; brentuximab vedotin and nivolumab for relapsed disease.
- CLL: targeted therapy with BTK inhibitors or venetoclax-based combinations rather than chemoimmunotherapy.
- Multiple myeloma: quadruplet or triplet induction (VRd ± daratumumab), autologous transplant in eligible patients, maintenance, and MRD assessment.
- HSCT: autologous for myeloma and relapsed lymphoma; allogeneic for high-risk acute leukemia, MDS and marrow failure. Conditioning is myeloablative or reduced intensity. Complications include graft-versus-host disease (acute: skin, gut, liver), sinusoidal obstruction syndrome, engraftment failure, infection and secondary malignancy.
Worked example
A 34-year-old presents with pancytopenia, DIC and promyelocytes with Auer rods. The correct action is to start ATRA immediately along with arsenic trioxide, transfuse to keep platelets above 30–50 × 10⁹/L and fibrinogen above 150 mg/dL, and confirm with PML-RARA testing. Waiting for molecular confirmation before starting ATRA costs lives.
Traps
- Delaying ATRA in suspected APL; missing differentiation syndrome (fever, weight gain, pulmonary infiltrates) and its treatment with dexamethasone.
- Quoting BCR-ABL milestones without stating the timepoint.
- Offering autologous transplant to a patient with active marrow disease or an available matched sibling who needs graft-versus-leukemia effect.
- Forgetting prophylaxis for Pneumocystis, herpes and hepatitis B reactivation with rituximab.