Congenital granular cell epulis: Immunohistochemical and ultrastructural observations

Tumor cells of the congenital granular cell epulis (GCE), unlike those of the granular cell tumor (GCT), did not stain with antiserum to S-100 protein. Based on immunohistochemical findings it is concluded that the GCE and GCT differ in histogenesis; furthermore, ultrastructural studies of the authors are in agreement with others in supporting a mesenchymal origin of the GCE.