Source / episode info
- **Episode:**81
- **Title:**Divine Intervention Episode 81 – USMLE Step 1 Hematology Review Part 3 (Oncology)
- **Published:**2019-02-21
- Source:Episode page
One-liner
This episode reviews key myeloproliferative neoplasms (MDS, PMF, PV, ET, CML), the spectrum of plasma cell dyscrasias (MGUS, MM, Waldenstrom's), and critical high-yield concepts including tumor lysis syndrome, hyperviscosity, and bone remodeling pathways.
High-yield summary
- Myelodysplastic Syndromes (MDS): Characterized by ineffective hematopoiesis due to early apoptosis of precursors in the bone marrow, leading to peripheral pancytopenia and macrocytic anemia (MCV > 100). Look for dysplastic features like "pseudo-Pelger-Huet" bodies.
- Primary Myelofibrosis (PMF): A myeloproliferative neoplasm characterized by bone marrow fibrosis due to megakaryocyte-derived cytokines (e.g., TGF-). Classic findings include tear-drop shaped reticulocytes/megakaryocytes (dacrocytes) and massive hepatosplenomegaly.
- Multiple Myeloma (MM): Defined by the presence of monoclonal protein (M protein) and bone marrow plasmacytosis, often presenting with CRAB criteria: Calcium elevation, Renal failure, Anemia, Bone pain/lesions.
- Polycythemia Vera (PV): The most common myeloproliferative neoplasm associated with a JAK2 mutation; classically presents with aquagenic pruritus and can cause Budd-Chiari syndrome (hepatic vein thrombosis).
- CML Staging: Progression is defined by the loss of differentiation: Chronic Phase -> Accelerated Phase (blasts < 20%) -> Blast Crisis (loss of differentiation, becomes AML).
Learning objectives
- Differentiate between Myelodysplastic Syndromes (MDS) and Myeloproliferative Neoplasms (MPN).
- Recognize the classic clinical and laboratory findings associated with Primary Myelofibrosis (PMF), Polycythemia Vera (PV), and Essential Thrombocythemia (ET).
- Master the staging of Chronic Myeloid Leukemia (CML) based on blast percentage and differentiation ability.
- Apply the CRAB criteria to diagnose Multiple Myeloma (MM) and distinguish it from MGUS or Waldenstrom's Macroglobulinemia.
- Understand the pathophysiology and management of acute hematologic emergencies like Tumor Lysis Syndrome (TLS) and hyperviscosity syndrome.
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