[Serous papillary cystadenoma of the rectum].

The authors describe a rare clinical observation: development of the serous papillary cystadenoma of the borderline malignancy in the rectum in a 53 year-old women. 20 years ago she was operated on and bilateral ovarian tumors were removed. The authors regard the tumor of the rectum to have arisen de novo. The hypothesis of local origin of the tumor is supported by the fact that no remnants of any tumor were found in the tissues adjacent to the rectum. The major part of the tumor was presented by the benign structures identical to the cellular composition of the normal fallopian tube mucosa. Poorly differentiated structures occupied small areas in the secondary papilla formed in the large cystic cavity. Possible mechanism of the development of this tumor are discussed.