Laparoscopic resection surgery for malignant transformation of extragonadal endometriosis by the "pincer" approach.

Up to 1% of women with endometriosis develop endometriosis-associated neoplasms [1]. Most endometriosis-associated malignant tumors develop from the ovarian endometriomas, whereas those developing from extragonadal lesions are extremely rare, estimated at 0.2% [2]. Because they are uncommon, a treatment protocol for the malignant transformation of extragonadal endometriosis lesions has not been clearly defined. When the lesion is confined to the site of origin and R0 resection is achieved, the 5-year survival rate is between 82% and 100%; therefore, complete resection should be performed [3]. The patient in this video had previously undergone hysterectomy, bilateral salpingo-oophorectomy, left nephrectomy, and low-anterior resection of the rectum due to severe endometriosis. Ten years after the surgery, the patient had a 6 cm endometrioid adenocarcinoma developing from the residual endometriosis lesion at the left uterosacral ligament that involved the bladder, left ureter, and rectum. In this case, the tumor was attached to the pelvis due to infiltration of the left sacrospinous ligament. To completely remove the tumor, we used laterally extended endopelvic resection with abdominoperineal resection of the rectum. We used the laparoscopic-perineal-laparoscopic approach (pincer approach) because improved visualization of the left sacrospinous ligament increases the probability of achieving complete resection [4]. Pathological R0 resection was achieved without intraoperative or postoperative complications. Thus, for tumors that are firmly attached to the pelvic floor, the pincer approach can be useful for achieving R0 resection. The informed consent for use of this video was taken from the patient.