Growth of Dermoids from Skin Implants to the Nervous System and Surrounding Spaces of the Newborn Rat

T HERE is significant evidence supporting the concept of t r auma as the cause of some spinal epidermoid cysts. Many reports refer to spinal epidermoids tha t developed several years following single or multiple lmnbar punctures. In most instances the taps were per formed for the diagnosis and t r ea tmen t of tuberculous meningitis. Choremis, et al., 4 were the first to suggest a relationship between direct implantat ion of epidermis by a lumbar puncture needle and subsequent t umor formation. Gibson TM demons t ra ted t ha t in over 60% of skin punctures a small piece of epidermis remains in the needle. He also produced dermoids by subcutaneous implanta t ion of skin into rats. Successful skin t ransplants to the central nervous sys tem in exper imental animals have not been reported as far as we know. We describe here a simple method for the direct implantat ion of skin honlografts into the spinal epidural and subarachnoid spaces of immature animals and even into the cord itself. Similar implants into frontal cortex have also been successful.