Endometrial Cyst Presenting as a Vague Abdominal Lump in a Postmenopausal Woman.

A postmenopausal woman presented with a predominantly right-sided abdominal lump, insidious in onset and not associated with any aggravating or relieving factors. Physical examination revealed a soft cystic mass extending from the right hypochondrium to the right iliac fossa region crossing the midline. Ultrasonography of the abdomen and pelvis showed a large cystic anechoic area noted in the abdomen extending from the epigastric region to the pelvis. Contrast-enhanced CT of the abdomen and pelvis showed a large non-enhancing cystic lesion in the pelvis suggesting the possibility of a right ovarian cyst or mesenteric cyst. Laparotomy was performed and the excised specimen was sent for histopathological analysis, which confirmed it to be an endometrial cyst.