Dumbbell-shaped nonpsammomatous malignant melanotic schwannoma of the cervical spinal root

Melanotic schwannoma is a very rare tumor of Schwann cell origin, which can develop in various locations, similar to conventional schwannoma. This tumor has a malignant potential and therefore careful therapy is required.

To describe a case of melanotic schwannoma with a histopathologically and clinically malignant behavior.

Case report.

A 64-year-old man presented with sensory changes in his arm and gait disturbance. Magnetic resonance imaging revealed a dumbbell-shaped tumor at the left C7 spinal root, which was hyperintense on T1-weighted images and generally hypointense on T2-weighted images in comparison with conventional schwannoma; however, the peripheral zone was relatively hyperintense, and the central zone was hypointense like a target sign.

The tumor was partially resected and diagnosed to be nonpsammomatous malignant melanotic schwannoma. The patient experienced local recurrence and metastases to the bone and lung and finally developed quadriplegia. Radiation therapy failed to palliate the symptoms.

Some melanotic schwannomas present with an aggressive behavior, which thus leads to poor prognosis. We should therefore be familiar with its characteristic clinical imaging and pathologic findings to provide a correct diagnosis and appropriate treatment for such patients.