title: Megakaryoblastic transformation of primary thrombocythemia.
abstract: The progression of primary thrombocythemia (PT) into acute leukemia was diagnosed in a 64-year-old man who was previously treated by hydroxyurea without alkylating agents or radioactive phosphorus. Such an event has only been reported in very rare cases. The blast cells had a lymphocytic morphology but were identified as promegakaryoblasts by the ultrastructural demonstration of platelet peroxidase. These data suggest that a megakaryoblastic transformation could occur in PT as had previously been reported in chronic granulocytic leukemia.
mesh_terms: D000368:Aged; D002471:Cell Transformation, Neoplastic; D005976:Glutaral; D006801:Humans; D007951:Leukemia, Myeloid / Q000097:blood; D008297:Male; D008533:Megakaryocytes / Q000648:ultrastructure*; D010544:Peroxidases / Q000378:metabolism; D013922:Thrombocytosis / Q000097:blood*
chemical_list: D010544:Peroxidases; D005976:Glutaral