A Case of Intramedullary Spinal Cord Metastatic Melanoma (P4.239)

Objective: We describe an atypical presentation of intramedullary melanoma metastases with a rapidly progressive course, initially misdiagnosed as transverse myelitis. Background: Intramedullary metastasis from a cutaneous melanoma is an exceptionally rare cause of myelopathy, and due to its infiltrative nature is impossible to differentiate from transverse myelitis on spinal imaging alone. In all case reports reviewed intracranial metastasis was already present, which as well as an important diagnostic clue may be pathologically crucial in dissemination to the cord via cerebrospinal fluid. Design/Methods: A 69-year-old man was evaluated for acute left leg numbness and weakness; 24 hours later this involved bilateral lower extremities with urinary incontinence and inability to ambulate. Medical history was significant for a 1.9mm melanoma of the left arm resected 5 years prior with clear margins and no axillary lymph node involvement. Examination was consistent with acute myelopathy with a sensory level at T4. Cerebrospinal fluid analysis was remarkable only for elevated protein with negative microbiologic, oligoclonal and viral studies. Serum was negative for autoimmune, metabolic or paraneoplastic causes of transverse myelitis. MRI of the neuroaxis with gadolinium showed abnormal signal within the spinal cord at the T5-T6 level extending inferiorly and enhancing at T9, with multiple hemorrhagic lesions in the brain. PET CT showed multiple hyper-metabolic pulmonary nodules. Results: The patient was initially treated with 5 days of high-dose methlyprednisolone. Endobronchial biopsy then revealed metastatic melanoma. He received palliative radiotherapy to T8-9, but had no improvement in neurologic function. Conclusions: This case highlights the importance of even remote cancer history; despite recurrence rates for intermediate risk melanoma falling to Disclosure: Dr. wrigley has nothing to disclose. Dr. Plancher has nothing to disclose. Dr. Curry has nothing to disclose.