Lumbosacral metastatic extradural Merkel cell carcinoma causing nerve root compression--case report.

A 63-year-old man presented with a rare metastatic Merkel cell carcinoma (MCC) involving the lumbosacral spine and causing nerve root compression. Magnetic resonance (MR) imaging revealed an extradural soft tissue mass at the L5-S1 levels. The tumor was subtotally removed and chemotherapy was administered, but he died of multiple metastases from the primary epigastric tumor. Lumbosacral metastatic epidural tumor can manifest as lumbar disc disease symptoms, but MR imaging can non-invasively and rapidly reveal the presence of spinal epidural tumor and any extension to the spinal canal. Extradural MCC metastasis in the lumbosacral area should be considered in the differential diagnosis of radicular symptoms caused by disc herniation.