Page 710 - Motor Disorders Third Edition

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to 50% (11) and up to 89% of children studied (13), followed
either by ependymoma in one-third of patients (11) or neu-
ronal tumors, including ganglioglioma and ganglioglioneu-
rocytoma, in one-quarter (13) to one-third of children (14),
with only rare instances of glioblastoma. The majority of
pediatric astrocytomas occur proximally in cervical and cer-
vicothoracic (11) or thoracic regions (13), while ependymo-
mas generally have a more distal location in the distal cord,
cauda equina, and filum terminale or conus medullaris.
Among adult patients, the most common IMSCT was
ependymoma, seen in 83% of patients, usually in a cervical or
thoracic location in three-quarters of patients. This was fol-
lowed by subependymoma and glioblastoma in 10% in one
series (8), and astrocytoma and ependymoma respectively in
40% and 34% of patients. Overall 81% of astrocytomas were
grade I, all of which were surgically removed. Almost 50%
were grade II, 12% of which were surgically removable, and
20% were grade III or IV, none of which were surgically resect-
able. One-third of tumors located respectively in cervical, tho- lar studies as may be needed and available (24).
racic and cerviothoracic spinal regions (10). Only about 10%
of astrocytoma in children are high-grade tumors, while the
majority of low-grade fibrillary astrocytomas show an indo-
lent biological behavior and a more benign course compared
to their adult counterparts, explained in part by the histologi- many factors, both direct and indirect, the former due to
cal features, and age being a favorable prognostic factor. In a
comparison of the outcome of spinal cord astrocytoma, 60% of
patients younger than 21 years at diagnosis were alive without
recurrence 10 years after surgery compared to 40% at 5 years
without recurrence for patients older than age 21 years (15).
CLASSIFICATION
Tumors of the spinal cord can be divided into three catego-
ries based upon anatomic location: intramedullary, intradu-
ral extramedullary, and extradural (16). Extradural tumors,
which consist primarily of systemic cancer metastases,
result in spinal cord compression. Intradural extramed-
ullary spinal tumors, which are for the most part benign,
are equally divided between meningiomas and peripheral
nerve sheath tumors (10, 17). Intramedually spinal cord
tumors, which constitute up to 10% of all primary spinal
cord tumors, are comprised mainly of ependymomas in 60
to 70%, astrocytomas in 30 to 40%, hemangioblastomas in
3 to 8%, and less commonly, gangliogliomas, lymphoma,
germinoma, melanoma, primitive neuroectodermal tumor
(PNET), lipoma, paraganglioglioma, teratoma, dermoid
cyst, and hamartoma, which have a preponderant location
in the cervical and thoracic spinal cord, and cervicodorsal
regions in surgical series (10, 18).
The WHO Classification of Tumors of the Central Ner-
vous System, the universal standard for classifying and
grading neoplasms, first published in 1979 (19), established
the histological typing of tumors, while the second edition
(20) advanced the introduction of immunohistochemistry
into diagnostic pathology. The third and current fourth edi-
tions (4, 21, 22) incorporated genetic profiles as additional
aids to the definition of CNS tumors, and included sections
on epidemiology, clinical signs, and symptoms, imaging,
prognosis, and predictive factors, and added several new
neoplasms and tumor variants.
The International Classification of Diseases for Oncol-
ogy (ICD-O-3) (23), which serves as an interface between
pathologists and cancer registries, provides histological cod-
ing for human neoplasms, including topographical codes
for spinal cord tumors. An accurate pathological diagnosis
is essential to diagnosis and management. To achieve this,
the histolopathological diagnostic process is rigorously
joined with the clinical history, preoperative imaging, and
any prior pathological diagnoses, as well as the results of
tumor biopsy tissue and ancillary studies, including immu-
nohistochemistry, electron microscopy (EM), and molecu-
CLINICAL PRESENTATION
The symptoms produced by spinal tumors may relate to
the site of tumor origin, the dynamics of growth and expan-
sion, and interference with intrinsic structures of the spi-
nal cord. Indirect tumor effects result from hydrocephalus,
syringomyelia, and leptomeningeal seeding or those attrib-
uted to preoperative treatment with corticosteroid therapy
and other medical conditions. In general, extradural lesions
lead to bony, radicular involvement, variable spinal cord
compression, and compromise of spinal blood vessels, with
the level and location of the lesion suggested by concomi-
tant motor, sensory, and reflex changes and the presence of
bladder, bowel, and sexual dysfunction.
Among 430 patients of mean age 49 years in the Patient
Care Evaluation (PACE) Study (9), primary tumors of the
spinal cord were noted in 71% of patients, spinal meninges
in 24%, and caudal equina in 5%; meningioma accounted
for 24%, ependymoma 24%, and schwannoma 21%. Com-
mon presenting neurological symptoms included pain in
52%, numbness and tingling in 46%, followed by incoordi-
nation and imbalance in 27%, and urinary incontinence in
13%. Concomitant neurological signs included weakness,
fasciculation, and wasting in 31%, sensory loss in 30%,
gait difficulty in 22%, and hyperreflexia of the legs in 23%,
with Babinksi signs in 8% of patients. Those with cauda
equina tumors manifested significant pain reported in 83%
of patients with less than half noting sensory symptoms,
weakness, or urinary incontinence, suggesting a full-blown
cauda equina syndrome.