[Extracranial schwannoma of the ENT region. Review of the literature with a case report of benign schwannoma of the base of the tongue].

BACKGROUND: Schwannomas are benign, usually solitary, encapsulated neoplasms which arise from the Schwann cells of the nerve sheath. They often originate from the VIIIth cranial nerve. Extracranially, about 25% of all Schwannomas are located in the head and neck. The lateral cervical region and the mouth are the most common sites. Schwannomas arising from the base of the tongue are very rare, and only a few cases have been reported so far. CASE REPORT: We add the case of a 31-year-old woman who had been suffering from slowly increasing dysphagia for about 4 years. Examination revealed a firm, smooth-shaped, nodular swelling about 3.0 cm in diameter arising from the base of the tongue. SYMPTOMS AND DIAGNOSIS: The symptoms of Schwannomas are nonspecific, and depend on size and location. Sonography, CT or MRI may be helpful for estimation of the tumor margins and infiltration of surrounding structures. To confirm the diagnosis, however, microscopic examination is necessary. Characteristic histological signs are the palisading of the spindle-shaped Schwann cells around the central acellular area (so-called Verocay bodies). THERAPY AND PROGNOSIS: The therapy of choice consists of surgical removal of the tumor; Schwannomas do not recur if they are completely removed. In contrast to multiple neurofibromas (von Recklingshausen's disease) Schwannomas almost never undergo malignant transformation.