INTRAOSSEOUS SCHWANNOMA AFFECTING THE MANDIBLE: CASE REPORT AND IMMUNOHISTOCHEMICAL ANALYSIS.

Schwannomas are neoplasms arising from differentiated Schwann cells. These tumors most often affect the soft tissues of the head and neck and rarely occur in intraosseous location. To date, approximately 90 cases of schwannoma affecting the jaws have been reported. A 52-year-old female patient was referred for evaluation of an asymptomatic mandibular lesion. Imaginologic analysis showed a large radiolucent lesion involving the mandibular body and ramus with expansion of the buccal and lingual cortical plates. An incisional biopsy was performed, which microscopically revealed hypercellular and myxoid hypocellular areas composed of spindle cells with ill-defined cytoplasm. Nuclear palisading around cellular areas was evident. Immunohistochemistry showed positivity for S-100, CD56, and CD34 (weak). The Ki-67 labeling index was <3%. Schwannomas in an intraosseous location affecting the jaws may mimic odontogenic and nonodontogenic cysts and tumors; thus, a strict clinicopathologic correlation is required for a correct diagnosis. [ABSTRACT FROM AUTHOR]