OBJECTIVETo study the clinicopathologic and immunohistochemical features of cystic neoplasms of the pancreas.

METHODSNinety-two cases of cystic neoplasm of pancreas were retrieved from the Department archival file during the period from 1999 to 2005. Histologic features were studied and the tumors were typed according to WHO classification. Immunohistochemistry was also carried out using paraffin-embedded tissues.

RESULTSThe age of patients ranged from 16 to 80 years. The patients included 33 males and 59 females. The tumors varied from 2 cm to 21 cm in diameter. They consisted of intraductal papillary mucinous neoplasm (36/92), serous cystic neoplasm (18/92), solid pseudopapillary tumor (18/92), mucinous cystic neoplasm (14/92), cystic pancreatic ductal adenocarcinoma (4/92) and cystic pancreatic endocrine neoplasm (2/92). Immunohistochemical study revealed variable staining patterns, with frequent overlaps between different tumor types. In general, serous cystic neoplasm expressed MUC1, while mucinous cystic neoplasm was positive for MUC-5AC, intraductal papillary mucinous neoplasm for MUC-2 and cystic pancreatic ductal adenocarcinoma for MUC-1. On the other hand, solid pseudopapillary tumor expressed alpha-antitrypsin, alpha-antichymotrypsin, vimentin and progesterone receptor.

CONCLUSIONSAccurate diagnosis of pancreatic cystic neoplasms requires correlation of clinical findings, radiologic examination, histologic features and immunostaining results. Pathologic distinction is important because of different prognostic significance. Two-thirds of pancreatic cystic neoplasms are premalignant or malignant and warrant surgical resection, whereas the remaining one-third (including pseudocyst and serous cystadenoma) are benign and can be treated conservatively.