[Disseminated peritoneal leiomyomatosis. A rare disease picture].

After taking oral contraceptive hormones continuously for 17 years, a 44 year old patient developed enlarging uterine leiomyomas and multiple small to tiny subperitoneal nodules throughout the pelvic peritoneum. Histologically and immunohistochemically, the nodules proved to be leiomyomas. Similar nodules were induced in young female guinea pigs by injecting them with estradiol twice weekly. The first nodules appeared after four months. Approximately 50 cases of Leiomyomatosis peritonealis disseminata (LPD) have been reported to date in the world literature. Of these, 23 patients were pregnant. Seventeen had taken oral contraceptives continuously for many years (from 8-17). The developing leiomyomatous nodules probably arise from the Müllerian epithelium, which is distributed throughout the subperitoneal mesenchyme. By appropriate individual predisposition and excessive hormonal stimulation, the Müllerian derivatives proliferate along lines of myofibrous differentiation. Since the oral contraceptives all contained in addition to estradiol the synthetic gestagen norethindrone (or lynestrenol) and since these same hormones led to identical tumor nodules in animal experiments, it seems to suggest, that the stimulation of the Müllerian epithelium results from a specific combination of hormones. A similar combination of hormones may develop endogenously during a hormonally disturbed pregnancy. To prove these assumptions, larger case and interdisciplinary studies are needed. It is of clinical importance to realize, that the dormant Müllerian epithelium may be stimulated by excessive hormones to proliferate and that the proliferations produced, such as the benign nodular tumors of LPD, must be differentiated from nodular metastases of malignant tumors.