[Acute transformation of chronic myelomonocytic leukemia with t(1;3) (p36;q21) abnormality]

A 66-year-old man was given a peripheral blood test because of low grade fever. Leukocytosis was detected, and the blood and bone marrow findings were consistent with those of chronic myelomonocytic leukemia. Three months later the hematological findings were: WBC 58,800/microliter (19% blastoid cells, 22% monocytes), Hb 9.0 g/dl, and a platelet count of 116 x 10(4)/microliters. A bone marrow examination revealed the presence of 52.6% blastoid cells and dysmegakaryocytopoiesis, including micromegakaryocytes. Serum and urinary lysozyme levels were elevated. Karyotypic analysis detected t(1; 3) (p36;q21), but not major bcr/abl mRNA. The patient was given a diagnosis of acute transformation of chronic myelomonocytic leukemia. Despite treatment, he died about 3 months later. t(1;3) is occasionally observed in cases of myelodysplastic syndrome (MDS) and leukemia. Patients with t(1;3) often exhibit dysmegakaryocytopoiesis; furthermore, acute leukemia develops more readily in those who also have MDS. Cases of long-term survival are rare.