A Scar That Menstruates: The Enigma of Episiotomy Site Endometriosis

Background: Episiotomy scar endometriosis is an uncommon form of extrapelvic endometriosis that occurs following vaginal delivery. It results from iatrogenic implantation of endometrial tissue into the perineal wound during episiotomy repair. Due to its rarity and nonspecific presentation, diagnosis is often delayed or mistaken for more common perineal pathologies. A 26-year-old woman P1L1 Case Presentation: presented with pain and swelling in the left perineal region for six months, which worsened cyclically with menstruation. She had a history of vaginal delivery with a left mediolateral episiotomy one year earlier. On examination, a firm, tender nodule measuring 1 cm was palpated at the episiotomy scar. Ultrasonography revealed a multiloculated cystic lesion with internal echoes, and MRI confirmed a well-defined lesion without sphincter involvement. Wide local excision was performed under spinal anesthesia, and histopathology revealed endometrial glands and stroma with hemosiderin-laden macrophages—confirming endometriosis. Postoperatively, the patient remained asymptomatic and showed no recurrence at the three-month follow-up. Episiotomy scar endometriosis, though rare, should be suspected in reprodu Conclusion: ctive-age women presenting with cyclical perineal pain and a scar nodule following vaginal delivery. Clinical awareness and imaging are key to diagnosis, and complete wide local excision remains the definitive treatment. Early recognition prevents recurrence and preserves perineal function.