Long-Term Follow-Up after Surgical Management for Atypical Endometriosis: A Series of Nine Cases

Background and Objective: Atypical endometriosis is reported to possess a precancerous potential attributed to premalignant changes characterized by cytological atypia and architecture proliferation. Although the coexistence of atypical endometriosis and neoplasms has been reported, cases of atypical endometriosis transformation to carcinoma are rarely reported. The purpose of this case series was to evaluate the prognosis of atypical endometriosis. Subjects and Methods: Data from nine women who underwent surgical treatment including cystectomy and salpingo-oophorectomy with or without hysterectomy and diagnosed with atypical endometriosis was analyzed. Between January 2006 and January 2018, the clinical characteristics and prognosis of atypical endometriosis were evaluated. Results: During the follow-up period, eight of nine patients with atypical endometriosis did not develop malignant epithelial tumors, although one patient developed endometrioid carcinoma, grade 1, 48 months after her right laparoscopic cystectomy. The median overall survival period for all patients was 68 (range 13–131) months. Conclusion: When we encounter the cases of atypical endometriosis, it is necessary to consider the possibility of ovarian cancer and carefully follow those cases for long periods.