Up to the end of 1959, 244 patients, with a total of 249 spinal tumors, had undergone surgery in the Neurologic Institute of Milan (Istituto neurologico di Milano, Italy). The growths were examined histologically, with the exception of 19 endomedullary gliomas, in which decompression was carried out, but no biopsy was done. From this series, we have excluded the cases of medullary compression consequent upon primary or metastatic vertebral tumors, as well as angiomas of the spinal cord, since these are vascular malformations. In our material, the frequency of the latter (21 examples) among the total of spinal tumors was over 8 per cent, more than twice the figures given by Wyburn-Mason (23) and by Therkelsen (18). Spinal tumors occurred about equally in the two sexes: 128 in men and 116 in women. If 6 cases of Recklinghausen's neurofibromatosis in which the medullary involvement was generalized are excluded, the remaining 243 tumors were distributed as follows: The thoracic spine was the most frequent sit...