Unopposed endogenous and exogenous estrogenic stimulation has been considered by most investigators to have a role in the pathogenesis of
carcinoma of the endometrium. Although a few cases of "
sarcomas" of the endometrium that had developed in an estrogenic setting have been reported, a clear-cut association between estrogenic stimulation and these forms of
endometrial cancer has not been established. We report six cases of endometrial
sarcomas complicating ovarian
thecomas, polycystic
ovarian disease, or prolonged
estrogen therapy. Three ovarian
thecomas, which are considered to be estrogenic
tumors, were associated with endometrial malignant
mullerian mixed tumor, mullerian
adenosarcoma, and low-grade stromal
sarcoma in postmenopausal women. Polycystic
ovarian disease, a condition characterized by unopposed estrinism due to the peripheral conversion of excessive
androstenedione to
estrone, was found in a 27-year-old infertile woman with an endometrial malignant
mullerian mixed tumor. A pure
osteogenic sarcoma of endometrial stromal origin developed in a 28-year-old woman with
gonadal dysgenesis (
Turner's syndrome) who had received
estrogens for 18 years. The sixth woman, with an
empty sella turcica after
radiation therapy of a
pituitary adenoma, had an endometrial mullerian
adenosarcoma at the age of 40 years after 16 years of
estrogen therapy. None of these patients had had pelvic
radiation therapy. The evidence from this series of cases and from six additional cases identified in the literature suggests that the risk of endometrial
sarcomas may be increased by
estrogen therapy or endogenous disorders that lead to unopposed estrogenic stimulation of the uterus.