Spinal meningeal melanocytomas: clinical manifestations, radiological and pathological characteristics, and surgical outcomes

Abstract

Meningeal melanocytoma is a rare benign tumor, most frequently located in the posterior fossa and spinal canal. The aim of this study was to investigate the clinical manifestations, radiological features, management, and follow-up data of spinal meningeal melanocytomas. We present the clinical data and long-term outcomes from a consecutive surgical series of 16 patients with pathologically diagnosed spinal meningeal melanocytomas. All of the patients underwent surgical resection. Pre and postoperative MRI was performed. Follow-up data and neurological functional assessment is presented and discussed. The mean age at diagnosis was 42.0 years, with a significant male predominance. The primary clinical symptoms were weakness or numbness of the extremities. The appearance of melanocytoma on MRI is typically isointense to hyperintense on T1-weighted images, hypointense on T2-weighted images, and contrast enhancement tends to be remarkable and homogeneous. In most cases, gross total resection is achievable; however, in rare cases with dumbbell-shaped tumors involving the extraspinal region, a staging operation and subtotal resection should be attempted. During a mean follow-up period of 58.1 months, the symptoms were completely relieved in all the patients, and no tumor progression or recurrence was noted. Melanocytic tumors of the central nervous system have a typical appearance on MRI scans, varying with the content and distribution of melanin. However, the differential diagnosis between malignant melanoma and melanocytoma still depends on pathological criteria. Spinal meningeal melanocytoma has a benign course, and it is amenable for gross total resection. The outcome is favorable following complete resection.

Keywords: MRI; Melanocytomas; Spinal cord tumor; Surgical outcome.