Endometrial carcinoma presenting as hematometra mimicking a large pelvic cyst

Large pelvic cysts are commonly seen in gynecologic practice; their heterogeneous origin is reflected in their pleomorphic clinical features. We report the case of a 64-year-old multiparous postmenopausal woman with an unusual manifestation of endometrial adenocarcinoma that presented as hematometra mimicking a large pelvic cyst. In this case, hematometra was well demonstrated by transabdominal sonography, but transvaginal sonography allowed better visualization of the endometrial lining and suggested the correct diagnosis of endometrial cancer. Abnormal vaginal bleeding or hematometra in postmenopausal women should lead to assessment of the endometrial mucosa. Transvaginal sonography can be used to visualize neoplastic lesions in the endometrium when hematometra is detected through transabdominal sonography.