Lumbosacral radiculopathy secondary to L5 metastatic melanoma of unknown primary.

Lumbosacral radiculopathy secondary to spinal malignancy is rare. Spinal melanoma without cutaneous manifestations is even more unusual. We present the case of a 45-year-old physician with a history of degenerative disease of lumbar spine and chronic back pain who presented with increasing back pain with right radiculopathy despite conservative management for 6 months. Computed tomography showed a destructive lesion of the L5 vertebral body. Results from a biopsy guided by computed tomography suggested neoplasm of unknown origin. The patient underwent anterior vertebrectomy with instrumentation and fusion. Surgical pathology study results showed metastatic melanoma of unknown primary. The patient had no cutaneous manifestation of the disease. This is the first reported case of radiculopathy due to melanoma metastatic to the lumbar spine. In view of the atypical presentation of our patient's malignancy, we emphasize the importance of including malignancy of lumbar spine in the differential diagnosis of progressive lower back pain with radiculopathy.