What Are the Histological Features of Myeloproliferative Disorders?
In MPDs, bone marrow biopsy and aspiration are essential for diagnosis. The histological features vary depending on the specific disorder:
Polycythemia Vera: The bone marrow shows hypercellularity with an increase in red cell precursors. Megakaryocytes are often increased and clustered. Essential Thrombocythemia: Bone marrow is hypercellular with a marked increase in megakaryocytes, which are often large and show abnormal clustering. Primary Myelofibrosis: Early stages show hypercellularity with increased megakaryocytes and granulocyte precursors. Over time, the marrow becomes fibrotic, leading to a "dry tap" on aspiration. Chronic Myeloid Leukemia: The marrow is hypercellular with a marked increase in granulocytic precursors, often with a decreased proportion of erythroid precursors. The presence of the Philadelphia chromosome (BCR-ABL fusion gene) is a hallmark.
