Intramedullary epidermoid tumors of the thoracic spinal cord. Report of two cases.

Abstract

E PIDERMOID tumors involving the spinal cord are quite rare. 4,'~,8,~',11,1:* The opinion of the majority of authors is that these tumors arise from displaced normallydeveloping somatic cells. Recently, Van Gilder and Schwartz TM reported a method of producing epidermoid and dermoid tumors in the albino rat by direct skin implantation along the neuraxis; this evidence supports the concepts of a congenital origin or subsequent development after repeated lumbar puncture. The vast majority of intraspinal epidermoid tumors are intradural and extramedullary. They are commonly associated with a dermal sinus and occur usually in the lumbosacral segments. In 1962, Manno, et al.fl in a review of all reported cases, found only five tumors that they classified as being intramedullary. However, a critical review of these cases 4-3,~~ revealed that these were confined to the conus medullaris and extended down the dural sac; hence, they were not truly intramedullary. Gross 6 reported a case in which the tumor initially appeared intradurally and upon reoperation years later was found within the substance of the cord. King, 7 in 1957, reported a case quite similar to the ones we are about to describe and stated that he was unable to locate a similar case in the literature. In none of these series has a long-term follow-up been reported giving the results of operative management of a recurrent tumor or the effect of radiotherapy upon such a lesion. We are able to provide these data in the following cases.