Key Clinical MessageCystic IPMN-B is a rare liver disease with a high risk of malignant transformation (64%-89%) and poses diagnostic challenges. We describe a case of a 74-year-old woman with a large bilobar mucinous cyst in the left liver lobe associated with its atrophy managed with left hepatectomy. The cyst was lined with columnar cells with apical mucin and had radiological communication with the bile duct.Key words: cystic IPMN-B; Mucinous Liver Cyst; Hepatectomy