Multinucleated giant cell neoplasm of pancreas: light and electron microscopy features.

The morphological features, as demonstrated by electron microscopy, of a rare pancreatic neoplasm indistinguishable from giant cell tumor of bone by light microscopy is presented. These findings are compared with those of the only other case studied by electron microscopy and reported. Features were noted in both studies that are strongly suggestive of the epithelial origin of this neoplasm. However, there were similarities between the material from the current case and giant cell tumor of bone. Degree of differentiation seems to be the most likely determinant of the degree of similarity of the pancreatic neoplasm to the skeletal lesion.