A case of nodular fasciitis arising in the auricle

Nudular fasciitis is an uncommon benign proliferative lesion in the head and neck, and is extremely rare in the auricle. A case of nodular fasciitis arising in the auricle of 53-year-old man is reported by immunohistochemical and electron microscopical studies. Initially, he had noticed a small painless nodule on the posterior side of right auricle, and it grew up rapidly in size over 2 months. A biopsy revealed nodular fasciitis. This lesion was resected totally with the auricular cartilage. Histological examination revealed proliferation of spindle-shaped cells and immunohistochemical-positive staining was observed with actin, and focally positive staining was seen with vimentin. Electron microscopically some tumor cells contained dilated rough endoplasmic reticulum and myofilament-like bundles in cytoplasm.