[Histologic and immunohistochemical profiles of benign granular cell tumors. Report of 41 cases].

Since the descriptions of << myoblastomas >>, later denominated granular cell tumours, many immunohistological and ultrastructural studies have been undertaken with the aim of establishing their histogenesis. Now the hypothesis of a neurogenic origin appears clear. From the large number of cases (53) diagnosed in Geneva over a period of 10 years, we decided to do a retrospective study of these tumours with regard to their immunohistological phenotypes, using the following markers: S100 protein (S100), Neuron specific enolase (NSE), Vimentin, Chromogranin, Glial fibrillary acidic protein (GFAP), Keratin, Epithelial membrane antigen (EMA), Desmin, Smooth muscle alpha actin. 100% of tumours were positive for S100, and 90% for NSE, which confirms the neurogenic origin. 70% were Vimentin positive, with however a variable intensity. All the other markers were negative. Immunohistological staining for S100 and NSE may be useful tool in the diagnosis of these tumours.