Clinical implications of mucinous nonneoplastic cysts of the pancreas

An undercharacterized subclass of pancreatic mucinous cysts without histologic characteristics of neoplasia is emerging. This article aimed to highlight the clinical characteristics and implications of this new subset of pancreatic cystic lesions.

The clinical, radiologic, and pathologic features of all cysts that underwent operative resection at a tertiary referral pancreatic disease center from February 2005 to June 2009 were reviewed. Immunohistochemistry for mucinous peptide antigens was selectively performed.

Of 104 operations, a pathologic examination revealed 52 intraductal papillary mucinous neoplasms, 9 mucinous cystadenomas, 17 serous cystadenomas, 9 pseudocysts, 5 solid pseudopapillary tumors, 2 carcinomas, 1 cystic pancreatic endocrine tumor, and 2 other cystic lesions. Seven mucinous cysts without neoplastic features were identified, representing 2% of all pancreatic resections, 6.7% of all resected cysts, and 10.3% of the 68 mucinous cysts. There was no evidence of cytologic atypia, papillary growth, or ovarian-type stroma in any of the cases. MUC1, MUC2, and MUC5AC were expressed in 83%, 0%, and 100%, respectively. There has been no recurrence with a mean follow-up of 44 months.

This underappreciated entity belongs to the family of mucinous pancreatic cysts. However, unifying clinical characteristics that would prevent unnecessary resections in patients harboring these seemingly benign lesions are currently lacking.