Low-grade extrauterine endometrial stromal sarcoma arising from vaginal endometriosis: a case report and literature review.

Extrauterine endometrial stromal sarcoma arising from malignant transformation of the vagina is an extremely rare condition. The diagnosis is often difficult as the symptomatology and pathological features overlap with that of pelvic endometriosis. A 38 years old female presented with complaints of dyspareunia, dysmenorrhea, and painful defecation along with blood-stained vaginal discharge for a year. Examination revealed the presence of multiple brownish irregular nodules in posterior vaginal fornix and fixed tender nodules which on biopsy revealed florid vaginal endometriosis. She improved symptomatically on medical therapy. After 18 months of diagnosis, she presented again with a necrotic growth in posterior fornix, which on repeat biopsy revealed a low-grade endometrial stromal sarcoma. Laparotomy revealed a 7×5 cm mass in the pouch of Douglas, infiltrating the posterior vaginal wall and rectum. A complete cytoreductive surgery with retrograde hysterectomy, excision of posterior vaginal wall and rectosigmoid resection was done. The patient is disease-free at a follow-up of 65 months.