Polypoid cystic adenomyosis of the uterus: report of a case.

A case of focal adenomyosis of the uterus with unusual gross features is presented. The patient, a 43-year-old woman, had experienced abnormal vaginal bleeding for 8 years. Hysteroscopy revealed a polypoid mass compatible with a submucosal leiomyoma, and a hysterectomy was performed. The uterus showed a 7 x 5 x 3-cm firm polypoid mass attached to the anterior wall that occupied most of the uterine cavity and protruded through the cervical os. It contained a large, central, cystic cavity filled with bloody fluid that communicated with the endometrial cavity through a fistula-like tract. Both the surface of the mass and the inside of the cystic cavity were covered by endometrial mucosa, and there were endometrial islands in the intervening wall. The differential diagnosis of this unique form of adenomyosis included polypoid submucosal leiomyoma with invagination of endometrium, endometrial polyp, submucosal leiomyoma with invagination of endometrium, endometrial polyp, and uterine diverticulum.