Trisomy 21 in acute promyelocytic leukemia.

We present a case of a 64-year-old male, diagnosed to have acute promyelocytic leukemia with trisomy 21. He came to the hospital with bleeding secondary to disseminated intravascular coagulation. Promyelocytes in the blood and bone marrow contained abundant, prominent azurophilic granules. Cytogenetic studies revealed trisomy 21. The karyotypic abnormality reverted back to normal 46,XY, pattern after chemotherapy. The typical morphologic and cytogenetic features of acute promyelocytic leukemia are briefly discussed.