Acute promyelocytic leukemia: Cytogenetics and bone-marrow culture

Abstract

Six patients were diagnosed as having acute promyelocytic leukemia (APL) according to FAB criteria. One patient conformed to the M3 variant. Informative cytogenetic results (G‐banding) on five of the patients showed that three of them, including the M3 variant, had the 15;17 translocation in bone‐marrow or blood cells. Cells with the translocation were accompanied by cells with a normal karyotype in all patients and no other chromosomal abnormality was present. This first report of the 15;17 translocation from the South Pacific region is relevant to the uneven geographical distribution of APL patients with the translocation. Five of the six patients, including the M3 variant, showed a distinctive pattern of cell growth in agar culture characterized by a profusion of small, uniform clusters containing 6–20 cells with the appearance of promyelocytes. The remaining patient had a pattern of cell growth more typical of M2 acute leukemia. This cell growth pattern may be useful in diagnosing and monitoring the course of APL.