Intraspinal epidermoid tumor of the sacral canal presenting with urinary retention.

A case of epidermoid tumor of the sacral area with S3 root irritation resulting in bladder dysfunction is presented and its possible relationship to spinal puncture is discussed. Precautions should be taken to prevent this complication by using a stylet instead of a plain needle. The recognition of this complication should always be in the differential diagnosis of a child with back pain, gait abnormality and bladder dysfunction with a history of spinal puncture.