Background: Intraparenchymal endometriosis of liver is rare. It may present as liver tumour and the diagnosis is not usually established till after surgery.
Case outline: A 48-year-old postmenopausal woman presented with right upper quadrant pain and a cystic liver mass. Liver function tests and tumour markers (alphaFP, CEA, CA 19-9, and CA 125) were normal. Radiological imaging (USS, CT and MRI) suggested a thick walled cystic mass involving segments IV and VIII with complex intracystic septations. Frozen section at operation suggested a benign cystadenoma. The cyst was enucleated using a CUSA (Cavitron ultrasonic aspirator). The final histology confirmed endometriosis.
Discussion: Eleven cases of hepatic endometrioma have been reported and only four in postmenopausal women. Preoperative diagnosis poses a challenge and so far none of the cases have been diagnosed preoperatively. Surgery remains the treatment of choice. Accurate diagnosis at time of operation may avoid extensive liver surgery and its associated morbidity.