Soft tissue perineurioma of the tongue: report of a case and review of the literature.

Perineurioma is a rare benign tumor of the peripheral nervous system distinct from schwannomas and neurofibromas. It may be intraneural or extraneural (in the soft tissue). Extraneural soft tissue perineuriomas are uncommon; rare cases have been reported in the oral cavity. We present a case of soft tissue perineurioma in the tip of the tongue. The tumor was characterized by slender spindle cells, arranged in short fascicles or whorls, and focal areas showing a distinct storiform pattern. Tumor cells showed the immunohistochemical profile of perineurial cells, including epithelial membrane antigen. Smooth muscle actin, S-100, and CD34 were not expressed by the tumor cells. The tumor was surgically excised and in 2 years there has been no recurrence. Knowledge of the tumor in the oral cavity is important to reach a correct diagnosis and to avoid unnecessary aggressive local excision.