Neurofibroma of the Cauda Equine: Report of a Case

Abstract

Primary neoplastic lesions arising from the spinal cord, nerve roots, and meninges comprise about 15 per cent of all central nervous system tumors. Among 35,000 autopsies in Vienna, Schlesinger (1898) recorded 994 tumors of the central nervous system, of which 151 were spinal cord neoplasms. Ewing (1931) collected 400 spinal cord tumors; out of that number 37, or 9 per cent, were neurofibromas. Peers (1936) found 4 intra-medullary spinal cord tumors in 10,592 autopsies. Adson (1939) reported 557 intraspinal neoplasms; 163 of these, or 29 per cent, were neurofibromas. Of 275 spinal cord tumors removed surgically, Elsberg (1941) classified 59 as perineurial fibroma or neurofibroma. Of these, 54 were intradural neurofibromas; only 5 were extradural. The case to be reported here represents a simple intradural circumscribed neurofibroma originating from the cauda equina, in a young soldier, recognized preoperatively and classified chiefly through the medium of myelography with Pantopaque. Grossly, a neurofibroma is a circumscribed, encapsulated lesion, varying in size, arising from nerve-sheath cells. It may be single or multiple, benign or malignant, simple or plexiform, and may involve either the central or peripheral nervous system. Microscopically, elongated cells are demonstrable, showing a parallel arrangement of their nuclei, called palisading. Occasionally this tumor may show degenerative cystic change. If it arises from the perineurial connective tissue it is called a perineurial fibroblastoma. It may occur at any age, but single lesions are more common in the earlier age group. If it develops within the spinal canal, its symptoms depend on its location, size, and the amount of pressure it exerts on the spinal cord or nerve roots. It may be intradural or extradural, may be globular, bulbous, fusiform, or dumb-bell shaped. Neurofibromas of the cauda equina are less common than similar tumors in other parts of the spinal canal. They may occasionally reach large size, producing extensive bone destruction involving several vertebral segments. Case Report A 23-year-old soldier was inducted into the Army about two months prior to admission to the hospital. Five years earlier, after an effort of lifting, he experienced low-back pain. This had recurred on several occasions following similar effort. Two years before admission a severe attack followed a fall on the back, from a low truck. The attacks lasted two to three weeks, but in the long intervals between attacks the patient was relatively free of discomfort and able to carry on his routine duties on the farm. The attack was in the nature of a severe burning pain in the lumbosacral region, radiating to the right side of the scrotum, and the anteromedial aspect of the right thigh, with inconstant numbness and tingling sensations in the lateral aspect of the right thigh and muscle twitching in that region.