Large mucinous biliary cystadenoma with "ovarian-like" stroma: a case report.

Hepatobiliary cystadenomas are rare tumors that are difficult to diagnose preoperatively. They can reach large sizes that make them real intraoperative "surprises". A 63-year-old woman, presented with a symptomatic huge abdominal cystic mass, underwent complete resection of the mass with safety margins. Histopathological report revealed mucinous hepatic cystadenoma with "ovarian-like" stroma and areas of sclerohyalinization. The differential diagnosis of the large cystic tumors which occupy the right hemiabdomen must include the biliary cystadenoma; the complete resection of the tumor with safety margins avoids local recurrence, and therefore represents the optimal therapy because of the malignant potential of the disease. The postoperative follow-up includes abdominal ultrasound or CT scan and CA 19-9 measurement.