Epibulbar granular cell tumor. Report of a case and review of the literature.

Abstract

The granular cell tumor (GCT) is a common, usually benign, neoplasm of uncertain histogenesis that may affect any organ in the body. It occurs rarely in ophthalmic sites, where orbital location is most frequent. The purpose of this report is to describe a unique case of an epibulbar, subconjunctival GCT in a child. Histopathologic examination of the excised tumor included standard and immunohistochemical staining of formaldehyde-fixed, paraffin-embedded tissue. Histopathologic study showed the characteristic morphology of GCT. Immunohistochemistry was strongly positive for vimentin, weakly and partly positive for neuron-specific enolase, and negative for S-100 and HAM-56. Granular cell tumor must be added to the differential diagnosis of epibulbar masses. Immunohistochemistry of the tumor in this case suggests an uncommitted mesenchymal cell origin.