Multinucleated Giant Cells in Various Pancreatic Diseases

Abstract

According to the classification of pancreatic carcinoma, rare neoplasms containing numerous multinucleated giant cells are categorized as giant cell carcinoma in anaplastic ductal carcinoma. Osteoclast-like giant cells in the giant cell carcinoma are considered of reactive histiocytic origin, whereas the stroma is considered as a neoplastic component. However, multinucleated giant cells are occasionally found even in usual pancreatic diseases. In 62.5% of usual ductal adenocarcinomas, and in 34.5% of chronic pancreatitis cases, we found giant cells. Various histological and immunohistochemical types of giant cell were found. Epithelial atypical giant cells are positive for epithelial markers and negative for mesenchymal markers; they are bizarre atypical cells in the cancer nest. This type was seen in pleomorphic-type anaplastic carcinoma and in 55% of usual ductal adenocarcinoma. Coexpressed-type atypical giant cells are positive for both epithelial markers and vimentin. Non-expressed-type atypical giant cells are pleomorphic giant cells negative for epithelial markers and CD68. Coexpressed- and non-expressed-type giant cells are considered to be epithelial neoplastic cells with a non-cohesive invasive growth pattern. This type was seen in 10% of usual ductal adenocarcinomas. Mesenchymal-type giant cells are negative for epithelial markers and positive for mesenchymal markers (vimentin and CD68). These giant cells are considered of reactive histiocytic origin. In the giant cell carcinomas and usual ductal carcinomas, they are found in the lumen of the tumor gland or stroma. In chronic pancreatitis, they are accompanied by protein plugs, pancreatic stones, abscesses, and fat necrosis. This type was seen in 15% of usual ductal adenocarcinomas and 34.5% of chronic pancreatitis cases.