Histogenesis of leiomyomatosis peritonealis disseminata (disseminated fibrosing deciduosis).

Leiomyomatosis peritonealis disseminata (LPD) is a rare clinical entity. Widespread subperitoneal nodules of apparent smooth muscle are found in patients who are pregnant or have recently been so. This clinical appearance together with mitotic figures found in frozen sections suggests malignancy. We believe, in contrast, that LPD is a benign reparative process in which fibroblasts replace subperitoneal decidua.