Schwannoma in the floor of the mouth; A case report

Schwannoma or Neurilemoma is a benign neoplasm of the nervous system originating from Schwann cells. It develops from the neural sheath of peripheral motor, sensory, sympathetic, and cranial nerves except for the optic and the olfactory nerves which basically lack Shwann cell sheaths. Approximately 25% to 45% of the schwannomas occur in the head and neck region. Usually, the mass is asymptomatic, though tenderness or pain is reported in some instances. Tongue is the most common site for oral neurilemomas. Occasionally, the tumor arises centrally within the mandibular bone and thus makes jaw expansion.Case Report: A 22-year-old man presented with a mass in the right side of his mouth floor allegedly existing from six months earlier. The mass was surgically removed. Sample sections of the mass were prepared. In microscopic examination with H&E, there were two areas of wavy and spindle cells within a loose and myxomatous stroma compatible with the known Antoni A and B patterns of Schwannoma. The tumor cells showed a diffuse positive immunohistochemical reaction to S-100 which supported the diagnosis. Schwannoma is a benign soft tissue tumor which mostly involves tongue within oral cavity. This tumor rarely occurs in other regions such as mouth floor.