The patient is a 71-year-old female with a history of polycythemia vera (PV) with JAK2 mutation diagnosed in 2014 without further follow-up regarding treatment. She presented to our hospital in October 2020 with shortness of breath. She was found to have myeloid blast transformation with 22% blasts on peripheral blood with underlying TET2, TP53 and ASXL1 mutation. The patient was enrolled in a clinical trial with decitabine and venetoclax and is undergoing bone marrow biopsy after a cycle of therapy.

The images depicted below are typical of an end-stage fibrotic phase Ph-negative myeloproliferative neoplasms. While early non-fibrotic stages maybe distinguished easily on morphologic grounds, end-stage fibrotic phase of MPNs uniformly demonstrate mild osteosclerosis, fibrosis and hyperchromatic megakaryocytes as noted here.