Abstract
Background: The presence of endometriosis is not uncommon even in ectopic organs such as intestines during the reproductive years. In rare cases, it is difficult to distinguish endometriosis from rectal cancer, and an accurate differential diagnosis is very important for the selection of therapy and strongly influences the prognosis of these patients.
Case: A rare case of rectal endometriosis is reported. A 21-year-old woman was admitted to our hospital because of rectal polyps pointed out by a practitioner, whose had been consulted for constipation and melena. Her family history was positive for familial polyposis. An endoscope revealed assemblin polyps and submucosal swelling in the rectum.Furthermore, a left ovarian cyst and hydronephrosis for the left ureteral stenosis were recognized. A partial rectal amputation and left ovariotomy were performed on the suspicion of rectal cancer or endometriosis.
Conclusion: We could rule out malignancy and suggest endometriosis from the frozen sections. Some tubular clusters which seemed to be normal proliferative phase endometrium, and scattered interstitial cells were intermingled in the imprint cytological specimens. Therefore, this case was diagnosed as a rectal endometriosis. Immunohisto-chemically, endometrial cells in the rectum were positive for both estrogen and progesterone receptors. Histological examination revealed endometriosis not only in the rectum, but also in the left ovary and the surrounding tissue of the left ureter.
