It is possible to differentiate mixed tumors from other lesions of the spinal canal by the typical clinical history and the characteristic roentgenologic evidence. It is by the early recognition and treatment of these tumors that good results by surgical removal are obtained.
Mixed tumors of the spinal canal are uncommon. In 1883 Chiari1 reported the first case of an epidermoid tumor. In 1931 Hosoi2 collected 10 cases of teratoid tumors occurring since 1883. Gross in 19343 collected 19 cases of dermoid and epidermoid tumors from the literature, to which he added 1 case. In 1938 Bradford4 brought the literature up to date by collecting 9 cases of dermoid or epidermoid cysts of the spinal canal reported since 1934.
Mixed tumors are now accepted as arising from embryonic rests.5 At the stage of embryonic development at which the neurectoderm is separated from the medullary plate,
LYLE A. FRENCH, WILLIAM T. PEYTON. MIXED TUMORS OF THE SPINAL CANAL. Arch NeurPsych. 1942;47(5):737–751. doi:10.1001/archneurpsyc.1942.02290050039003