[Extramedullary pleural myelo-megakaryoblastic crisis during hematological chronic phase in chronic myeloid leukemia]

A 77-year-old man, in whom chronic myeloid leukemia (CML) had been diagnosed in October 1990, was admitted to hospital with right chest pain in November 1992. Bone marrow examination revealed the chronic phase of CML. Chest X-ray showed right pleural effusion. The cells from pleural effusion were positive for CD7, CD13, CD33, CD41a, including CD33, CD41a-double positive cells in 57.5%. Southern blot analysis revealed 3'bcr rearrangement. Electron microscopic examination showed the presence of platelet peroxidase. An abnormal karyotype with various additional chromosomes was observed. This is a rare case of extramedullary pleural myelo-megakaryoblastic biphenotypic crisis during the chronic phase of CML.