Hidden in the Scar: A Rare Case of Vulvar Endometriosis Mimicking Bartholin's Cyst at an Episiotomy Site.

BACKGROUND

Vulvar endometriosis is an exceptionally rare manifestation of extrapelvic endometriosis, particularly when located at the site of a prior episiotomy. Often misdiagnosed as more common vulvar pathologies, these lesions may present with cyclical pain and swelling, mimicking Bartholin's gland cysts or infected epidermal inclusion cysts.

CASE: We report the case of a 25-year-old gravida 3 para 2 woman with long-standing dysmenorrhea, dyspareunia, and a right vulvar mass that fluctuated with her menstrual cycle. Initially presumed to be a Bartholin's cyst, the lesion failed to respond to antibiotics and sitz baths. MRI revealed a complex vaginal wall cyst without classic signs of pelvic endometriosis. Examination under anesthesia and aspiration of chocolate-colored fluid raised suspicion for an endometriotic lesion. Surgical excision confirmed endometrial glands and stroma with hemosiderin-laden macrophages-consistent with vulvar endometriosis at the site of a right mediolateral episiotomy scar. Postoperative recovery was uneventful, and the patient experienced complete resolution of symptoms.

CONCLUSION

This case highlights the diagnostic challenge of vulvar endometriosis in women with prior perineal trauma. Clinicians should maintain a high index of suspicion for endometriosis in cyclical vulvar masses-especially when located along episiotomy scars and unresponsive to conventional treatment. Early recognition and surgical excision can be curative and significantly improve quality of life.