Case for diagnosis. Dorsal nodule in a 10-year-old male.

Granular cell tumors (GCTs) are rare soft-tissue neoplasms. GCT immunohistochemistry is positive for S-100, NSE, and CD68. This report describes the case of a 10-year-old male who presented with a dorsal nodule. A biopsy revealed aggregates and sheets of large epithelioid and spindle cells. The cells had abundant eosinophilic granular cytoplasm. Immunohistochemical analysis was positive for CD68, NKI/C3, and synaptophysin; weakly positive for NSE; and negative for S-100, SOX10, HMB45, Melan A, cytokeratin, SMA, EMA, and CD163. The Ki-67 index was less than 1%. A diagnosis of an S-100 negative, cutaneous, benign GCT was determined.