Utility of bone marrow biopsy in myeloproliferative neoplasm with special reference to megakaryocyte morphology

Objectives: Bone marrow histopathology is now being included in the diagnostic approach of myeloproliferative neoplasm (MPN) along with other clinical, molecular, and cytogenetic investigations. Thorough assessment of megakaryocyte morphology and its topography is the cornerstone of the segregation of MPN subtypes. Apart from its diagnostic role, bone marrow biopsy histology also plays a crucial role in prognosis. The aim of this study is to emphasize the significance of bone marrow biopsy in the diagnosis as well as prognosis of MPN with special focus on megakaryocyte morphology and topography. Material and Methods: Bone marrow biopsy slides and the needful information’s of the previously diagnosed MPN patients were retrieved from the well-maintained records of the department. Hematoxylin and eosin-stained sections were examined along with reticulin fiber assessment. Additional staining procedures were also done according to the need. Results: Breakpoint cluster region – abelson (BCR-ABL)-positive chronic myeloid leukemia (CML) was the most common MPN subtype. Male gender was commonly affected, with an overall mean age incidence of 46.85 ± 17.71 years. The mean hemoglobin level and packed cell volume were significantly high in cases of polycythemia vera (PV) as compared to other MPNs. Classic trilineage cell proliferation was observed in PV, whereas various combinations of different proliferative cell lines were seen in other MPN. Essential thrombocythemia showed giant forms; on the other hand, CML revealed the abundance of micro-megakaryocytes. Grade 3 reticulin fibers are seen in PMF. Conclusion: Megakaryocyte morphology and its distribution in the bone marrow are one of the major findings to look for the exact categorization of MPN subtypes.