Aggressive endometriosis: report of a case.

A 54-year-old premenopausal woman presented with abdominal pain, constipation, and raised serum CA-125 levels during routine follow-up of a low-grade endometrial stromal sarcoma with prominent sex cord-like features, which had been treated by vaginal hysterectomy 4 years previously. The findings at laparotomy included: a 100-mm unilocular thick-walled right ovarian cyst, a solid 25-mm nodule in the left meso-ovarium, and a phlegmonous mass in the wall of the sigmoid colon, which proved to be a pericolic abscess due to diverticular disease. The ovarian cyst was a histologically benign endometrioid cystadenoma with stromal luteinization in the wall. Small islands of morphologically benign endometrial tissue were present in vessels of the meso-ovarium. The left adnexal nodule exhibited florid morphologically benign endometriosis, much of which was within and occluding large vascular spaces, and of apparently recent onset. No lesions resembled, in any way, the original stromal sarcoma. There was no evidence of endometriosis elsewhere in the pelvis or abdomen. The patient has made an uneventful recovery and is being monitored, as before, by tumor markers only. The discordance in morphology between the uterine sarcoma and the subsequent pelvic lesions was so complete as to raise doubts about any pathogenetic relationship between them. We propose the use of the term aggressive endometriosis to describe the changes observed.