Gnathic Schwannomas: A Report of Two Cases and Systematic Review of the Literature

BackgroundThe intraosseous schwannoma (IS) is a benign peripheral nerve sheath tumor postulated to arise de novo or from nerve fibers in preexisting nutrient canals. ISs are uncommon and comprise less than 1% of neoplasms originating in bone. We herein present two cases of mandibular schwannomas-the first case was a 66-year-old female with a four-month history of pain and pressure associated with an anterior mandibular radiolucency, and the second case was an asymptomatic 12-year-old female with separate radiolucencies of her mandibular symphysis and right posterior mandible. Incisional biopsies of all three lesions showed a benign spindle cell neoplasm with histologic features of a schwannoma; the tumor cells were strongly reactive for S-100. The patients underwent complete enucleation of their lesions and are without evidence of disease at ten months and five years, respectively.MethodsA systematic review was undertaken to evaluate the diagnostic features, treatment, and patient outcomes of gnathic schwannomas.ResultsA total of 93 cases were identified with the following demographic findings: predominance in females (57%); average age of occurrence of 37.3 years (8 to 77 years); mean size of 3.6 cm; and involvement of the mandibular body (37.6%), mandibular body and ramus (18.3%), and anterior mandible (18.3%). The predominant clinical sign was swelling (69.9%), and the most common radiographic presentation was a radiolucency (94.6%) with well-defined borders (72%).ConclusionAll cases were treated surgically, with an average follow-up interval of 22.9 months and a recurrence rate of 5.4%