Metastasis to the conus medullaris: case report.

Abstract

Metastasis from lung cancer to the conus medullaris has never been reported in the English literature, although three cases have appeared in the French and Japanese literature. Our case report is unique because the patient presented with a lumbar radiculopathy, an atypical presentation that was found to be caused by metastasis from lung cancer to the conus medullaris. A critical review of the pertinent literature related to metastatic neoplasms to the conus medullaris is also presented. We report the case of a 54-year-old man who presented with an L5 radiculopathy and was initially found to have a small disc herniation at L4-L5 on magnetic resonance imaging scans, which was ruled out as the case of his initial symptoms. In 3 weeks, the symptoms progressed with the development of urinary incontinence and right leg weakness. A magnetic resonance imaging scan of the lumbar spine showed a tumor at the conus medullaris. The patient underwent a laminectomy with removal of the tumor. Pathological examination of the tumor showed infiltrating differentiated adenocarcinoma. A 2.5 cm lung mass in the right middle lobe with surrounding adenopathy was found on a computed tomographic scan of the chest. The patient died 4 months later from systemic involvement and progression of his lung disease. This case report illustrates the rare presentation of a lumbar radiculopathy caused by a metastatic tumor to the conus medullaris. This was the first presentation for the diagnosis of lung cancer in this patient.