Papillary and cystic tumor of the pancreas. Two cases indistinguishable from islet cell tumor.

Two cases of large cystic tumor of the pancreas in two young women are reported. Gross features and conventional light microscopic appearances of these tumors were consistent with those described as being the so-called papillary and cystic tumor (PCT) or solid and cystic tumor. Immunohistochemical staining for neuron-specific enolase was positive diffusely in both cases. Special stainings with Grimelius' silver impregnation, and stainings for insulin, glucagon, and somatostain also were positive, although the population of positive cells was different in each case. Ultrastructural examinations confirmed the presence of numerous granules, probably neurosecretory, within the cytoplasm of many tumor cells in each case. Therefore, current cases were indistinguishable pathologically from the cystic nonfunctioning islet cell tumor. This study suggests that some PCT of the pancreas consist of endocrine cells predominantly.