Malignant Melanotic Nerve Sheath Tumor of the Parotid Gland: A Case Report and Literature Review.

Malignant melanotic nerve sheath tumor (MMNST) is a rare and aggressive peripheral nerve sheath tumor of Schwann cell origin that produces differentiated melanin and is clinically misdiagnosed as malignant melanoma. MMNST is most commonly observed in middle-aged adults and is often found in the midline of the spinal nerve or in the peripheral nerve area. It often manifests itself as a localized mass and/or nervous system involvement. To date, no standard guidelines are available for the treatment of MMNST. Herein, we reported a new case of MMNST that occurred in the parotid gland and reviewed the literature for pathological reports on its association with the oral cavity.