Intradural Extramedullary Metastatic Conjunctival Malignant Melanoma

Intradural extramedullary (IDEM) metastatic spine tumors of nonneurogenic origin, excluding leptomeningeal seeding, are very rare. Most patients with IDEM metastatic spine tumors of nonneurogenic origin have coexisting brain metastasis. We report a case of IDEM metastatic malignant melanoma without antecedent or coexisting brain metastasis.

A 52-year-old man presented with back pain, numbness in the lower extremities, paraparesis, and residual urine sensation after voiding. The patient had a history of conjunctival melanoma in the left eye and underwent surgical removal 3 years 6 months ago. Whole-spine magnetic resonance imaging showed an IDEM tumor at the T11 and T12 level, with compression of the spinal cord. Total laminectomy and resection of the tumor was performed. Pathology confirmed a malignant melanoma. Postoperatively, adjuvant chemotherapy was performed. Pain and neurologic deficit gradually improved, but complete recovery was not achieved.

Although rare, even without brain metastasis, malignant melanoma can cause IDEM metastatic malignant melanoma. For neurologic recovery and maintaining quality of life of the patient, surgical treatment for decompression of the spinal cord and postoperative adjuvant treatment for IDEM metastatic malignant melanoma should be considered unless multiple lesions are present in different parts within the spinal column.