TRISOMY-19 AS THE SOLE CHROMOSOMAL ANOMALY IN HEMATOLOGIC NEOPLASMS

Trisomy 19 was found as the sole chromosomal aberration in three hemat ologic malignancies: one chronic myelomonocytic leukemia and two cases of immunophenotypically immature acute myeloid leukemia (AML). A comp ilation of previously published hematologic neoplasms with +19 as the only change reveals that this anomaly is strongly associated with myel oid malignancies; 25 of 31 cases have been myelodysplastic syndromes ( MDS) or AML. Eight of the 11 MDS cases have been either refractory ane mia (RA) or RA with excess of blasts, and four of the 14 AML cases hav e had a preleukemic myelodysplastic phase, with the +19 accruing durin g the time of leukemic transformation. The AML cases have, in general, been either of early maturation arrest, i.e., undifferentiated or AML -M1/M2, or of myelomonocytic-monoblastic origin, i.e., AML-M4/M5. None of the MDS or AML cases with +19 has had a previous history of radio- or chemotherapy. We conclude that trisomy 19, as the sole anomaly, is a characteristic abnormality in de novo myeloid malignancies. No clin ical features seem to characterize patients with +19 AML and MDS and t he prognostic impact of the aberration remains to be elucidated.