Karyotypic rearrangements in 20 uterine leiomyomas

Short-term cultures from 106 uterine leiomyomas have been cytogenetically investigated. In 29 cases the number of metaphases was insufficient for analysis. A normal female karyotype was found in 57 tumors and clonal chromosome rearrangements in 20. A reciprocal translocation, t(12;14) (q14----q15;q23----q24), was observed in 10 tumors and probably represents a primary change of tumorigenic importance. In four of the tumors containing this specific anomaly, secondary chromosome changes were also present. The 10 karyotypically abnormal leiomyomas without a t(12;14) had various structural and numerical aberrations involving chromosomes 1, 2, 3, 4, 6, 8, 9, 10, 11, 12, 13, and 19. Different structural changes of chromosome 1 were the second most frequent abnormalities, being found in five tumors. Ring chromosomes were observed in three cases, but never as the sole change.