CYTOGENETIC FINDINGS IN UTERINE EPITHELIOID LEIOMYOMAS

Epithelioid leiomyomas of the uterus, unlike ordinary leiomyomas, show substantial epithelial differentiation. No chromosome abnormalities h ave been reported in uterine epithelioid leiomyomas before. We analyze d short-term cultures from five such tumors and detected abnormal kary otypes in four. A del(7) (q21.2q31.2) was found in two tumors, in one as the only change and in the other as a secondary aberration acquired during clonal evolution. Rearrangement of chromosomal band 12q15, ano ther of the cytogenetic hallmarks of ordinary uterine leiomyomas, was seen in the form of a t(10;12) in one tumor. Band 17q21 was involved i n structural aberrations in two cases. The data we present indicate th at epithelioid leiomyomas are fundamentally similar cytogenetically, a nd hence presumably also pathogenetically, to the much more common smo oth muscle-differentiated uterine myomas. The only differences hinted at are that epithelioid tumors may be karyotypically more complex and more often have rearrangements of 17q21.