Malignant Peripheral Nerve Sheath Tumor in the Course of the Mandibular Nerve

Malignant peripheral nerve sheath tumors are infiltrating, aggressive tumors that are soft tissue sarcomas. This article describes 3 patients with a tumorous swelling in the entire inferior alveolar nerve suspicious for malignant peripheral nerve sheath tumor, which is particularly rare in the trigeminal nerve. Diagnostic tools, surgical proceedings, and reconstructive procedures are presented.

Three male patients (age range, 58-68 years) with numbness, pain, and mild swelling in the sensory area served by the mental nerve presented to the Department of Oral and Maxillofacial Surgery and underwent diagnostic work-up including computed tomography, magnetic resonance imaging, fluorodeoxyglucose-positron emission tomography/computed tomography, and biopsy of the clinically visible tumor mass with histopathologic and molecular pathologic analysis.

Magnetic resonance imaging revealed the full extent of the tumor comprising the course of the entire mandibular nerve (1 case bilateral) starting in the trigeminal ganglion through the inferior alveolar nerve and ending in the mental foramen. Both a neurosurgical and a maxillofacial intervention with jaw replacement were necessary. Adjuvant radiation of intracranial closed resection margins and, in 1 case, of parts of the mandible was required.

To reveal the full extent of tumor spread of malignant peripheral nerve sheath tumors, sufficient preoperative imaging is crucial, as it is an important step in therapy planning. Magnetic resonance imaging and positron emission tomography/computed tomography have the best prospect of success in depicting the full extent of disease. Radical surgical management is the treatment of choice, whereas radiochemotherapy has an ancillary part.