- Schwannoma is a benign neoplasm originating from the neural sheath and occuring most often in the soft tissues of the head and neck. Intraosseous schwannoma (IS) is extremely rare, most commonly occurring in the mandible. This paper documents a case of IS and the histopathology, karyotyping, CT, and MRI in the diagnostic work-up. Histologically it was a classic schwannoma. The karyotype was normal. CT demonstrated destruction of the mandibular canal while MRI detected encasement of the inferior alveolar nerve by the tumor, and consequently the need to resect the nerve together with the tumor. Using CT and MRI, the morbidity associated with the anticipated surgery can precisely be determined preoperatively.