Description

Endometriosis occurs in about 10-15% of women, almost exclusively in the reproductive age. The most common symptoms are dysmenorrhoea, dyspareunia, pelvic or lumbar pain and infertility. One in four infertile women have endometriosis, as demonstrated by laparoscopy, and 30-40% of women who have endometriosis will be subfertile or infertile.

Endometriosis is defined as the presence of endometrial tissue (epithelium and stroma) outside the uterus. The commonest sites of implantation (in descending order of frequency) are the ovaries, uterine ligaments, Pouch of Douglas, serosal surface of the uterus, fallopian tubes and the serosa of bowel and bladder. More distant sites of involvement, such as the sciatic nerve, pleura, lungs and brain, have been reported. Endometriosis is thought to be caused either by retrograde seeding of endometrial tissue into the peritoneal epithelium, or metaplasia of the peritoneum into functional endometrial tissue, or a combination of both.

A variant of endometriosis is adenomyosis (“internal endometriosis”) where heterotopic endometrial tissue is found in the myometrium. Adenomyosis occurs frequently but is commonly underdiagnosed. It is found in 19-62% of hysterectomy specimens depending on the histological criteria used for diagnosis. It is important to diagnose as a cause of abnormal bleeding because the alternatives to hysterectomy, such as endometrial resection or ablation, are unlikely to be successful if the cause is deep adenomyosis.