Selected case from the Arkadi M. Rywlin International Pathology Slide Series: Leiomyomatosis peritonealis disseminata: report of 3 cases with extensive review of the literature.

We present the clinicopathologic features of 3 cases of leiomyomatosis peritonealis disseminata (LPD). The patients were 33, 34, and 41 years old at the time of diagnoses. The 3 women had undergone laparoscopic removal of multiple uterine leiomyomas between 1 and 6 years before the diagnoses of LPD. Laparoscopic uterine leiomyomectomies were performed on 3 occasions in patient 1, and once in patients 2 and 3 by the time a diagnosis of LPD was made. In patients 2 and 3, one of the multiple uterine leiomyomas had been qualified as mitotically active. Patients 1 and 2 received hormonal treatment before LPD was diagnosed. Malignancy was clinically and/or pathologically suspected in all the 3 cases. Patients 1 and 2 were managed conservatively. Patient 3 underwent radical hysterectomy with bilateral adnexectomy and omentectomy. Patients 1 and 2 belong to a rare subset of LPD that have fewer tumor nodules larger (5 to 10 cm) than typically seen. Patient 3 was classic in that she exhibited innumerable nodules measuring between a few millimeters and 1.5 cm, intraoperatively mimicking peritoneal carcinomatosis. Histopathologically, patients 1 and 2 were diagnosed as pure LPD, whereas patient 3 was diagnosed as LPD associated with endometriosis (adenomyosis type). Patients 1 and 3 had incipient foci of leiomyomatous changes in the blood vessel walls, at the site of the LPD tumors, supporting the hypothesis that these are de novo lesions arising locally and not migrated or disseminated from the previously excised or concurrent uterine smooth muscle tumors, usually seen in this context. Conceivably, laparoscopic leiomyomectomy with morcellation may play a role in the pathogenesis of this rare condition, at least in hormonally susceptible patients. Alternatively, LPD may derive from metaplastic submesothelial cells, a condition analogous to gliomatosis peritonei.