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.