Mucinous cystic neoplasm of the liver (MCN-L): a rare presentation and review of the literature

Mucinous cystic neoplasms of the liver (MCN-L, (previously referred to as cystadenomas or cystadenocarcinoma) are rare cystic tumors that occur within the liver parenchyma, or less frequently, in the extrahepatic bile ducts. They are reported to account for <5% of all liver cysts. The differential diagnosis of MCN-L includes intraductal papillary neoplasm of the bile duct (IPNB), intrahepatic cholangiocarcinoma with cystic change, echinococcal cyst, and a simple cyst. Invasive MCNs can only be differentiated from non-invasive MCNs by microscopic evaluation for the presence of ovarian-type stroma. Intraoperative biopsy and frozen section(s) are essential to differentiate MCNs from other cystic liver lesions. The treatment of choice is complete excision and can result in excellent survival with initial correct diagnosis. But its rare presentation and insufficient recognition frequently lead to an incorrect initial or delayed diagnosis or misdiagnosis.