Perianal endometriosis: A rare case report

Abstract Endometriosis is defined as the presence of endometrial tissue outside the endometrium and myometrium. Endometriosis is a relatively less common disease. Perianal endometriosis is a very rare entity. The lesion is usually localised in the episiotomy scars and uncommonly associated with cyclical pain. Here a case of perianal endometriosis in a 30 year old female patient having painful perianal swelling, who had a history of episiotomy is being reported. Clinically diagnosed as perianal abscess, the lesion was treated surgically by wide margin excision. Histopathological examination revealed presence of endometriotic tissue, composing of endometrial glands surrounded by endometrial stromal cells. Presence of endometrial stromal cells is confirmed by CD10 marker during IHC. Thus the histomorphological and IHC findings were consistent with the diagnosis of perianal endometriosis. Keywords: Endometriosis, Perineum, Pain, Abscess, CD10. Introduction Endometriosis is defined as the presence of endometrial tissue outside the endometrium and myometrium.[1] The most common anatomical sites of endometriosis are the ovaries, the uterosacral, broad, or round ligaments, the rectovaginal septum, cul-de-sac, fallopian tubes, and other pelvic organs. Endometriosis may occur rarely at the scar sites following operations in the lower abdominal wall on the uterus, fallopian tubes and episiotomy. Very rarely endometriosis can be seen in the perianal region (0.2% of ectopic endometriosis); mostly in the episiotomy scar.[1],[2] Endometriosis can manifest with a spectrum of symptoms ranging from chronic pelvic pain to infertility; but has been known to be asymptomatic in a small proportion of cases.[1] Clinical picture of scar endometriosis is typically a swelling or a nodule seen, a few weeks to years after surgery. Examination of the lesion reveals tenderness and occasional bleeding. Perianal endometriosis can clinically mimic an abscess as a result of the p