Microscopic description and IHC:

The cyst is multiloculated and does not communicate with any other structures.

Microscopically, the cyst is lined by columnar cells with low-grade dysplasia overlying ovarian type stroma (ER+)

The background liver shows features suggestive of mildly active steatohepatitis.


Mucinous cystic neoplasms arising in the liver are similar to their pancreatic counterparts. They usually occur in females and are composed of a mucin-producing columnar epithelial lining overlying an ovarian type stroma (the latter can be highlighted with CD10, inhibin, ER, or PR). In a large case series report by Regev et al, the authors presented 78 cases of cystic liver lesions greater than 4 cm from a large tertiary care medical center: The majority were simple cysts, echinococcal cysts=8, mucinous cystic neoplasms=8, invasive cystadenocarcinoma=1, and unclassifiable=4.

This report highlights importance of through sampling for cystic lesions in the liver to rule out higher grade component. For this particular case, 1 section per cm was submitted from random regions of the cyst.


Regev, Arie, et al. "Large cystic lesions of the liver in adults: a 15-year experience in a tertiary center." Journal of the American College of Surgeons193.1 (2001): 36-45.

World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of the Digestive System, Aaltonen LA, Hamilton SR (Eds), IARC Press, Lyon, France 2000.