Growths that lie both in the uppermost part of the vertebral canal and in the posterior cranial fossa are comparatively rare. Of 185 cases of tumor of the spinal cord verified by operation, in the experience of one of us, seven, or 3.7 per cent, lay both above and below the foramen magnum. New growths in this location are due either to a downward extension of a tumor which began in the posterior fossa of the skull or to one that originated within the vertebral canal and that has grown into the cranial chamber through the foramen magnum.
We have encountered six instances of extramedullary tumor in this location, one of which was so unusual that it is here reported in detail.
REPORT OF CASE
Clinical History.
—Mrs. R. H., aged 36, was admitted to the neurologic service of Mount Sinai Hospital, under the care of one of us, on