What are the key diagnostic criteria for myelofibrosis in a patient presenting with splenomegaly and cytopenias?

Key diagnostic criteria for myelofibrosis in a patient presenting with splenomegaly and cytopenias include a combination of clinical, laboratory, and bone marrow findings. Clinically, the presence of splenomegaly is a hallmark feature due to extramedullary hematopoiesis. Laboratory findings typically show cytopenias, which may involve anemia, leukopenia, or thrombocytopenia. Definitive diagnosis requires bone marrow biopsy demonstrating fibrosis, often graded by reticulin or collagen staining, alongside characteristic megakaryocyte atypia and clustering. Molecular testing for driver mutations such as JAK2, CALR, or MPL mutations supports the diagnosis but is not solely diagnostic. Additionally, exclusion of other causes of myelofibrosis, including autoimmune myelofibrosis, is essential. These criteria align with the International Working Group for Myelofibrosis Research and Treatment (IWG-MRT) consensus, which emphasizes bone marrow fibrosis and clinical features like splenomegaly and cytopenias as central to diagnosis NICE NG12 Tefferi et al. 2006. Recent literature further highlights the importance of integrating molecular mutation analysis and detailed morphologic assessment to refine diagnosis and prognostication Bose & Verstovsek 2016Vergara-Lluri et al. 2014.