Primary Spinal Malignant Melanoma Mimicking a Cervical Nerve Root Schwannoma: Case Report and Literature Review.

Primary spinal malignant melanoma (PSMM) is a rare cancer of the central nervous system (CNS), and PSMM of the spinal nerve root is even more extraordinary. PSMM of a nerve root can mimic the radiographic appearance of benign nerve sheath tumors, thus resulting in misdiagnosis until tissue diagnosis can be made. A 53-year-old African American woman presented with pain primarily involving the left aspect of her neck and shoulder for 2 years. Magnetic resonance imaging (MRI) of the cervical spine demonstrated a T1-hyperintense, T2-hypointense, homogenously enhancing, dumbbell-shaped, intradural extramedullary mass extending out through the left C2-3 foramen. A midline incision was used to perform a C2 and C3 laminectomy, and the mass was removed from the cavity. The histopathologic profile was consistent with the diagnosis of malignant melanoma. The present case report adds to the 110 cases of PSMM and the 20 cases of PSMM of the spinal nerve root in the existing body of literature. Radiographic and clinical features resemble that of the much more common schwannoma or neurofibroma requiring immunohistochemical analysis for definitive diagnosis. The optimal treatment for PSMM has not yet been defined due to its rarity and it is therefore important to report such cases in order to share our clinical experiences and provide data to other clinicians treating this uncommon disease.