[The histopathology and immunohistochemistry of granular cell tumour. A study of 12 cases with a brief historical note].

INTRODUCTION AND OBJECTIVE: Granular cell tumour (GCT) is a benign neoplasm of neural/schwannian origin, usually presenting as a single asymptomatic lesion, mainly located in the dermis and subcutaneous tissue or submucosa, although multiple tumours may occur. Microscopically, GCTs are composed of large cells with abundant eosinophilic, granular cytoplasm arranged in sheets, nests, cords or trabeculae. Based on the cytological characteristics and the presence of necrosis, three types are recognized: benign, atypical and malignant. We aim to present the cytological and immunohistochemical characteristics of 12 granular cell tumours.

MATERIALS AND METHODS: 12 cases of GCT were selected from the consultation files of one of the authors (COH) The paraffin embedded tissue was processed for immunostaining with S-100 protein, calretinin, CD68, α-inhibin, PGP9.5, CD57 (Leu7), CD63 (NKI / C3), Gap43 (growth-associated protein-43), SOX10, TFE-3 and Ki-67.

RESULTS AND CONCLUSIONS: 6 male and 6 female patients, with an average age of 40, made up the study group. The most frequent location for the tumours was in the subcutaneous soft tissues of the arms. There were no malignant cases. All tumours were positive for S-100, CD57, SOX10, calretinin, CD68, PGP9.5, α-inhibin and TFE-3, with a low Ki-67 (1-5%). Additionally, we reported, for the first time, the positive immunoreaction to Gap43 (growth-associated protein-43) in GCT.