Acute megakaryoblastic leukaemia with mediastinal tumor.

Acute megakaryoblastic leukemia (AMKL) is a rare myeloproliferative syndrome with a fulminant clinical course characterized by progressive pancytopenia, pallor, weakness and severe hemorrhage. We present a 18-year old male with pancytopenia and massive hemorrhage, lymphadenopathy, organomegaly, and with unusual presentation of retrocardial mediastinal tumor on the right side. The diagnosis of AMKL was established by combining cytological and immunocytochemical analyses of peripheral blood cells (blasts were GPIIIa and GPIb positive); by immunohistochemical analysis of lymph node (dysplastic megakaryocytes were GPIIIa and F VIII positive); in vitro culture studies confirmed enormous growth of CFU-Mk with high proliferative capacity. In spite of therapy, the patient died 3 months after the first signs of the disease.