Hepatic endometriosis: a rare case and review of the literature.

Hepatic endometriosis is one of the rarest disorders characterized by the presence of ectopic endometrium in the liver. To our knowledge, only 21 cases of hepatic endometrioma have been described in the medical literature. We report a case of a 36-year-old primiparous female with hepatic endometriosis forming a large cystic mass. The patient presented once with severe right quadrant pain as her only symptom and no history of endometriosis. Complete blood count and biochemical tests were normal. Abdominal ultrasonography and computed tomography scans suggested the presence of a 6.5 × 6.0 cm cystic mass in segment III of the liver. The mass was completely removed by local liver resection. The intraoperative frozen sections suggested a diagnosis of hepatic endometriosis. The diagnosis was confirmed through histological immunostaining without intrinsic abnormality. A preoperative diagnosis of hepatic endometriosis is made on the basis of considering the possibility in advance. Hepatic endometriosis should be considered in the differential diagnosis of a cystic liver mass despite conducting exhaustive investigations in the absence of characteristic clinical and radiological features. Histological examination is essential, and surgery remains the treatment of choice.