Page 709 - Motor Disorders Third Edition
P. 709
CHAPTER 43
Spinal Cord and Foramen Magnum Tumors
David S. Younger, James M. Powers
The past decade has witnessed advances in the classifica- imately 20% of all tumors in children under age 15 years
tion, diagnosis, and management of tumors of the spinal with a slight overall preponderance in boys, particularly
cord, meningeal and epidural compartments, and vertebral in the first two years of life (3). Employing criteria of the
and paravertebral spaces. This chapter reviews aspects of World Health Organization (WHO) (4), spinal cord tumors
childhood and adult primary tumors of the spinal cord, spi- comprised 5% (5, 6) to 10% (7) of primary CNS pediatric
nal meninges, and cauda equina. tumors, with three-quarters comprised of pilocytic astro-
cytoma, followed by anaplastic astrocytoma, ependymoma,
EPIDEMIOLOGY primitive neuroectodermal tumors, and ganglioglioma
each in 10% (5), 44% of which were intramedullary and
The estimated incidence of primary spinal cord tumors, 56% extramedullary. Among the latter, ependymomas and
both malignant and nonmalignant combined, was reported schwannomas were the most frequent (7).
as 0.74 per 100,000 person-years, with the highest rates
in adults, age 65 to 74 years, and mean age of 51 years at It may not be surprising to the inexperienced student that
diagnosis. Tumors of the spinal cord and cauda equina the spinal cord has the full spectrum of primary CNS neo-
accounted for 3% of primary brain and spinal cord tumors plasia because, like the brain, it contains the full spectrum of
overall, among 158,088 patients in The Central Brain elements, including neurons, astrocytes, oligodendrocytes;
Tumor Registry of the United States (CBTRUS), with nerve ependymal cells lining the central canals, blood vessels with
sheath tumors accounting for 40.5% of 4,838 patients age endothelium, pericytes, smooth muscle, and a leptomenin-
20 years and older, followed by ependymomas for 33.6%, geal covering comprised of fibroblasts, blood vessels, and
meningeal tumors for 6.1%, and astrocytoma or glioblas- arachnoid meningothelial cells. However, the relative pro-
toma, and lymphoma each for about 4% of patients (1). portion of tumor types found as primary tumors in the spinal
Among 16 pooled population-based United States cancer cord differs considerably from those reported in the brain.
registries combining 3,226 primary cord tumors diagnosed Equally important are the major differences in the reported
between 1998 and 2000 (2), 69% of tumors were benign, incidence of various pediatric intramedullary spinal cord
among which the spinal cord was the site of the tumor in tumor types as compared to those in adult patients, unparal-
70%, spinal meninges in 26%, and cauda equina in 4%. The leled by the respective incidence in the brain. The attempt to
commonest tumors were meningeal in 29%, nerve sheath radically surgically remove spinal cord tumors primarily in
in 24%, and ependymal in 23% of patients so studied, with adult patients (8–10), children (11–13), or both populations
a slight predominance of women over men and non-His- (14) resulted in valuable patient series and neuropathologi-
panic whites over non-Hispanic blacks. cal tumor material, rather than small biopsy specimens, from
which trends in the observed frequency of spinal cord tumor
Tumors of the CNS are the most frequent group of malig- types were ascertained. Low-grade fibrillary astrocytoma was
nant solid tumors in pediatric patients, comprising approx- the commonest intramedullary spinal cord tumor (IMSCT)
in pediatric patients, ranging from just under 40% (12, 14)
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