Lipoma of the cauda equina selectively involving lower sacral roots. Case report

A 44-year-old male patient suffering from sexual and voiding dysfunction did not exhibit any sensorimotor deficit except for a lax anal sphincter with loss of the bulbocavernosus reflex (BCR). The absence of both the electrically induced BCR and cortical evoked responses to stimulation of the dorsal penile nerve as well as partial denervation of the pelvic floor musculature suggested damage to the lower sacral roots. The site of the lesion as indicated by electrophysiological findings was confirmed by computerized tomography and magnetic resonance imaging. The operation revealed a lipoma involving a few cauda fibers which produced a distension in the region of the conus medullaris.