Endometriosis-associated intestinal tumors:A clinical and pathological study of 6 cases with a review of the literature

Malignant degeneration of rectal endometriosis

“…The key test for surgical specimens is immunohistochemical staining for cytokeratin-7 and cytokeratin-20, and for estrogen receptors (1,(10)(11)(12). Tumor tissue arising from the intestinal mucosa exhibits the following immunoreactivity profile: negative CK7, positive CK20, and negative estrogen receptors.…”

Endometriosis-Associated Intestinal Tumours: A Consequence of Long-Term Unopposed Oestrogen?

“…The occurrence of intestinal endometrioid malignancy is, however, uncommon. 1 The persistence or recurrence of endometriosis after a total abdominal hysterectomy and bilateral saplingo-oophorectomy is rare with one series reporting that no recurrence occurred without the use of HRT, as opposed to a 20% rate if oestrogen therapy was initiated. 3 Advice regarding the use of oestrogen therapy for women with a history of endometriosis with a surgical menopause is confusing.…”

“…However, malignancy arising from endometriosis in extra-ovarian sites is extremely rare. 1 Hormone replacement therapy (HRT) following surgical resection of endometriosis is often used in clinical practice as the potential benefits include symptom relief of surgical menopause (hypo-oestrogenism), the postponement of bone loss, and protection from cardiovascular disease. These benefits are traditionally seen to outweigh the possible risk from a recurrence of endometriosis.…”

Abdominopelvic Complications of Endometriosis

“…The rectovaginal septum, rectosigmoid colon, vagina, and pelvic peritoneum represented the majority of extragonadal sites. Other locations include: bowel, umbilicus, lymph node, urinary tract, pleura, diaphragm, lung, etc (Slavin et al, 2000;Van Gorp et al, 2004;Yantiss et al, 2001). Two possible explanations for the relation-ship between endometriosis and intraperitoneal cancer have been proposed: (i) endometriotic implants undergo malignant transformation secondary to genetic defects (p53 mutations) (Akahane et al, 2007) that also serve to enable the endometriosis to thrive, or (ii) women with endometriosis have a defect in their immune system that enables the endometriosis to flourish, and this baseline defect leaves them more susceptible to subsequent malignant transformation (Modesitt et al, 2002).…”

“…Extragonadal lesions are mostly endometrioid tumors (66%) and sarcomas (25%); clear cell histology is seen in only 4.5% of extragonadal malignancies. Tumors arising in endometriosis are predominantly low grade and confined to the site of origin (Slavin et al, 2000;Van Gorp et al, 2004). The histopathological criteria to classify a malignancy as arising from endometriosis include the demonstration of cancer arising in the tissue and not invading it from another source, and the presence of tissue resembling endometrial stroma surrounding the epithelial glands (Slavin et al, 2000).…”