Schwannoma of Bone

Abstract

Schwannoma is a rare benign intraosseous neoplasm, originating in Schwann cells of the nerve fibers and usually in sensitive nerves. It constitutes less than 1% of primary benign bone neoplasms. Most cases occur in the mandible; the sacrum is also a preferred site. Schwannomas are generally asymptomatic. Radiographs show a lucent, usually well-defined, intramedullary lesion. The tumor is very well-delimited, composed of spindle cells with wavy nuclei, with a focal palisading arrangement. Immunohistochemistry shows positivity for S100 protein. Once a relationship to neurofibromatosis is excluded, prognosis is excellent. Marginal resection or curettage is curative.