Chromosome analysis of uterine adenomyosis. Detection of the leiomyoma-associated del(7q) in three cases.

Adenomyosis is a uterine disease whose defining characteristic is the presence deep in the myometrium of endometrial glands and stroma. The condition is believed to arise from inordinate downward growth by contiguity from the endometrium rather than from in situ metaplasia or neoplasia. No acquired chromosome abnormalities have been associated with adenomyosis before. We analyzed short-term cultures from three cases and detected in all of them a del(7) (q21.2q31.2), a karyotypic anomaly that has hitherto been found repeatedly only in uterine leiomyomas. The cytogenetic similarity to leiomyoma suggests that the del(7q) was present in the mesenchymal or, more precisely, smooth muscle cells of the adenomyosis lesions. The very fact that clonal chromosome abnormalities were present questions whether the prevailing understanding of adenomyosis pathogenesis is adequate; the cytogenetic data would better fit a model of the disease envisioning the intramyometrial endometrial foci as having arisen through a neoplastic process.