Spinal cord compression with paraplegia in xanthomatosis due to normocholesterolemic sitosterolemia. A 48-year-old woman with a 30-year history of tendinous xanthomatosis developed paraplegia. The magnetic resonance image revealed extramedullary tumors. The analysis of her sera and tumors revealed increased amount of plant sterols, especially sitosterol, and the diagnosis of sitosterolemia was made. This is the first reported case of a patient with sitosterolemia who had the neurological complication of spinal cord compression due to extramedullary sitosterolemic xanthomas. 