I.Perineal Endometriosis

Abstract

Endometriosis involving the perineum is rare. We have collected total 110 cases of perineal endometriosis from the literature which included only 5 cases in Japan. The cases reported have steadily increased in recent years. Based on the fact that four new cases have been found in our Hospital in a relatively shorter period, we postulate much higher incidence of this disease in Japan than that would appear from the literature. Almost all of cases were managed by episiotomy associated with parturition, and the resultant endometriosis developed in previous episiotomy scar or at its adjacent site. The patients commonly complained of painful paeineal swelling during menstruation. The period of latency between episiotomy and manifestation of symptoms varied 45 days to 14 years, showing a peak between 1 to 3 years. The average age of patients was reported to be between 28 and 38 years from different institutions, being somewhat lower than the usual age group for patients with endometriosis. The perineal lumps were recognized as a single dark reddish or bluish nodule which varied 1 to 2 cm in diameter. On palpation, the mass was less movable, often tender due to periodic bleeding into cystic space. It increased in size and became painful during menstrual period ; after menses, the nodule became almost painless and decreased in size. When the patients fulfilled these clinical features, the preoperative diagnosis of perineal endometriosis is possible. The treatment of choice is simple local excision. Complementary hormonal therapy has been suggested in several cases with large or recurrent mass. Definite histologic diagnosis can be made by demonstrating endometrial glands and stroma, accom-panying hemorrhage, and granulation tissues characteristically containing large amounts of hemosiderin and lipid debris. The specimens obtained from Gase 3 and 4 of our series were subjected to ultrastructural analysis.Electron microscopic examination showed that the epithelial cells in specimen of Case 3 retained the fine structure of endometrial cells during proliferative phase, and those in specimen of Case 4did that of the cells during early secretory phase. As to histogenesis of perineal endometriosis, the most cases reported including our cases can reasonably be explained by direct wound implantation of shed endometrial tissues during delivery. On the basis of this implantation theory, we proposed some measures to eliminate the occurrence of this disease.