Intramedullary melanotic schwannoma: a rare presentation of a rare tumor. Illustrative case

J Neurosurg Case Lessons. 2023 Feb 13;5(7):CASE22391. doi: 10.3171/CASE22391. Print 2023 Feb 13.

Abstract

Background: Intramedullary melanotic schwannomas (IMSs) are rare spinal cord tumors, and a hemorrhagic IMS is an even rarer presentation of this uncommon lesion. The authors describe the second known case of a hemorrhagic IMS and briefly review the characteristics of IMSs.

Observations: The patient's initial presentation and imaging indicated an intramedullary thoracic spinal cord tumor impairing lower extremity function. Intraoperatively, the lesion appeared pigmented and hemorrhagic. Pathologic analysis determined the tumor to be an IMS.

Lessons: Melanotic schwannomas vary in presentation and can resemble malignant melanoma but are differentiated by pathologic markers. Lesions typically present as extramedullary masses in the thoracic cord. Intramedullary presentation is rare but should be considered for pigmented tumors.

Keywords: intramedullary spinal cord tumor; malignant melanotic nerve sheath tumor; melanocytic schwannoma; neurilemmoma; spinal cord neoplasm.