Plexiform (multinodular) schwannoma of soft palate. Report of a case.

ABSTRACT

Plexiform schwannoma is a rare benign neoplasm of the neural sheath characterized by a multinodular plexiform growth pattern. Only 5% of schwannomas have a plexiform or multinodular growth pattern. Schwannoma apparently derives from the Schwann cells. Extracranially, 25% of all schwannomas are located in the head and neck region, but only 1% show an intraoral origin. The intraoral lesions show a predilection for the tongue, followed by the palate, buccal mucosa, lip and gingival. Microscopic examination is necessary to confirm the diagnosis. Characteristic histological signs are the palisading of the spindle-shaped Schwann cells around the central acellular area, so called Verocay bodies. We report a case of a 21-year-old woman with a smooth mass of the soft palate that was gradually increasing. Surgical excision of the mass was done and the histopathology and immunohistochemistry study of the excised lesion revealed a multinodular plexiform schwannoma of the soft palate. The patient is under regular clinical control, with no signs of recurrence after 17 months. Plexiform schwannomas of the soft palate are mentioned very rarely in the English literature. This rare benign tumor is worthy of recognition because it can be misdiagnosed as plexiform neurofibroma.