LAUSR

BACKGROUND Biliary cystadenoma (BCA) is a rare benign tumor, accounting for only 5% of reported cystic lesions of the liver. Given its potential for malignancy and high rate of recurrence, surgical resection is the preferred treatment. Therefore, early and accurate preoperative diagnosis is critical to the choice of treatment. We here report the first male case of BCA in our hospital, diagnosed by our team and confirmed by pathological biopsy. This article aims to improve the understanding of this disease and help make a correct diagnosis to better manage it. CASE SUMMARY A 58-year-old man with irregular abdominal discomfort came to our clinic and was found to have a distended abdomen during physical examination. Computed tomography and magnetic resonance imaging both showed a huge cystic mass in the liver. The patient underwent left hepatic lobectomy, cholecystectomy, and liver cyst fenestration, and most of the masses had decreased in size as of the 6-mo follow-up. The pathological diagnosis was consistent with BCA, and no recurrence was detected after the surgery. BCA occurred mainly in middle-aged women. To the best of our knowledge, this patient is the 11th male case of BCA reported in the literature. CONCLUSION The combination of magnetic resonance imaging and magnetic resonance cholangiopancreatography is of great significance for the early accurate diagnosis of the disease and the choice of surgical methods.