Leigh's disease presenting as an intramedullary mass lesion

An unusual presentation of Leigh's disease consisting of rapid progression of leg weakness in a young child is discussed. Magnetic resonance imaging revealed an intramedullary mass lesion of the conus medullaris. Surgical exploration revealed only necrosis and inflammation. Subsequent studies revealed pathology in the cerebrum as well as the spinal cord. Metabolic abnormalities confirmed the diagnosis of Leigh's disease. The differential diagnosis of intramedullary mass lesions demonstrated by magnetic resonance imaging should include metabolic, inflammatory, and ischemic processes as well as neoplastic disease.