Complex karyotypic anomalies in a bizarre leiomyoma of the uterus.

Cytogenetic investigation of short-term cultures from a bizarre leiomyoma of the uterus, a tumor type not hitherto karyotypically characterized, revealed two abnormal clones with multiple complex rearrangements. Three-fourths of the aberrant cells were hypodiploid with the composite karyotype 38-44,XX,-6,-7,-10, -11,+20,-22,r(1),der(2)(:2p23----cen----2q13::1q21---- 1qter),der(2)t(2; 9)(p21;q13),t(5;?)(q35;?), t(5;?),(q35;?),+der(5)t(5;15)(q11;q15), der(8)t(8;11)(q24;q13),t(15;?)(p12;?),der(16)t(12;16)(q13;p13),+r,+mar. The remaining abnormal mitoses were hypotetraploid, with chromosome numbers ranging from 74 to 86. These massively rearranged cells showed the same markers that were found in the hypodiploid clone, but in duplicate, indicating that this clone had arisen through polyploidization of hypodiploid cells. Flow cytometry revealed a DNA index of 1.03.