Intraspinal epidermoid tumors caused by lumbar puncture.

It is well known that congenital intraspinal epidermoid tumors, while rare, do occur. That they may also be related to spinal puncture is less well understood. In the present article, four such cases are described, including one in which an earlier myelogram performed because of lumbar disk disease showed that no tumor was present prior to the spinal puncture. The pertinent literature is reviewed, and the probable mechanism of formation of such tumors and the means for avoiding it are discussed.