Congenital epulis: an ultrastructural and immunohistochemical study

In the light of recent findings concerning the presence of S-100 antigen in granular cell myoblastoma (GCM), we investigated by immunoperoxidase the presence of this antigen in a case of congenital epulis (CE). The absence of S-100 in CE granular cells is suggestive for antigenic differences with GCM. Upon ultrastructural investigation, bundles of collagen fibers were observed in the cytoplasm of CE granular cells and cells displaying features of initial cytoplasmic vacuolar transformation were also detected. Interstitial cells containing angulated bodies, a common finding in GCM, were not found.