Granular Cell Tumor: Immunohistochemical Assessment of Inhibin-α, Protein Gene Product 9.5, S100 Protein, CD68, and Ki-67 Proliferative Index With Clinical Correlation

Abstract

Our study expands the immunophenotype of GCT (S100, CD68, protein gene product 9.5, and inhibin-alpha) regardless of location and supports a neural origin. Intensity of immunohistochemical staining had no prognostic significance. Although 1 of the 2 recurrent GCTs had atypical features, the Ki-67 proliferative index did not distinguish reliably between typical (nonrecurrent) and atypical or recurrent GCTs. The significance of inhibin expression with regard to cell differentiation and pathogenesis is unclear and warrants further investigation.