Immunohistochemical Study of Solid-Pseudopapillary Tumor of the Pancreas

Paeng, Sung Sook; Chae, Seoung Wan; Choi, Ghee Young; Kim, Chong Jai; Chi, Je Geun; Kim, Yong Il; Kim, Woo Ho

Abstract

BACKGROUND/AIMS
The solid-pseudopapillary tumor of the pancreas occurs predominantly in young women, and most of them seem to be benign. The histogenesis of this tumor remains unclear. In this study, we reviewed the clinicopathologic findings and immunohistochemical staining pattern of eleven cases of solid-pseudopapillary tumor of the pancreas. METHODS: Eleven cases of solid- pseudopapillary tumor of the pancreas were reviewed and immunohistochemistry with 12 antibodies was performed. Two cases were examined by electron microscopy. RESULTS: All of the cases were female with a mean age of 27.9 years. Grossly, tumors were well demarcated multinodular mass with solid, cystic and hemorrhagic pattern and the mean diameter was 7.7 cm. Histologic examination showed that uniform cells formed solid sheets, and loss of cohesion produced pseudopapillae. Immunohistochemically, the all cases were reactive for vimentin and neuron specific enolase. Three cases expressed progesteron receptor, two cases expressed cytokeratin, and one case expressed alpha-1 antitrypsin. None of the cases showed expression of estrogen receptor, chromogranin, synaptophysin, lipase, epithelial membrane antigen, carcinoembryonic antigen or p53 protein. CONCLUSIONS: The solid-pseudopapillary tumor of the pancreas is possibly originated from pluripotent stem cells, but lacks definite evidences of endocrine or exocrine differentiation.