Dr. Bosemani is a Clinical Fellow, Division of Pediatric Radiology, and Dr. Tekes,
is an Assistant Professor of Radiology, Division of Pediatric
Radiology, The Russell H. Morgan Department of Radiology and
Radiological Sciences, Johns Hopkins University School of Medicine,
Focal spinal cord lesions, which can either be
neoplastic or non-neoplastic, are rare in children. The literature has
extensively described spinal cord neoplasms as a separate entity. Both
neoplastic and non-neoplastic lesions, however, may present with similar
clinical findings; hence, differentiating among them with imaging
remains crucial to their management. Our objective is to focus on
imaging features that help distinguish neoplastic lesions from
non-neoplastic lesions. Magnetic resonance imaging (MRI) is the most
sensitive imaging modality in the diagnosis and follow-up of these
Background and approach
Spinal cord tumors
account for only 0.5% to 1% of all central nervous system (CNS)
neoplasms. They are especially rare in childhood, with a frequency of
0.19 per 100,000 person-years, according to the Central Brain Tumor
Registry of the United States. A third of all intraspinal tumors are
located intradurally and intramedullary; in children, most
intramedullary tumors are malignant and are most commonly glial tumors.
The patient’s age at presentation varies without sex predilection.
spinal cord lesions often present nonspecifically; symptomology can
vary from a sudden onset to a slowly progressive course. Misleading and
vague symptoms can often result in delayed diagnosis and, thus,
increased morbidity. Progressive scoliosis, gait disturbance, motor
weakness and, most importantly, back pain should raise the possibility
of a spinal cord tumor and prompt imaging assessment. In children with
back pain, MRI of the entire spine should be performed, since pain can
be referred from a higher or lower level than the actual lesion
location. The vast majority of spinal cord tumors are treated with
debulking surgery. Follow-up imaging for residual disease and recurrence
is often necessary, further favoring MRI over CT as the imaging
modality of choice. Functional sequences, such as diffusion weighted
imaging (DWI) and diffusion tensor imaging (DTI), provide detailed
anatomical location of the tumor and its relationship to important
Spinal cord neoplasms
spinal cord neoplasms are glial tumors: astrocytomas (60%) and
ependymomas (30%). Nonglial tumors include ganglioglioma/gangliocytomas,
teratomas, hemangioblastomas, metastases, primitive neuroectodemermal
tumor (PNETs), germ cell tumors, and melanomas; these constitute about
10% of all spinal cord tumors (Table 1). Focal cord expansion is the
most typical MR imaging feature of spinal cord tumors. Other salient
imaging characteristics include variable contrast enhancement and cyst
formation. If there is no focal cord expansion or considerable mass
effect, non-neoplastic etiologies should be considered first. Cysts can
be tumoral or nontumoral. Non-tumoral cysts are usually present in the
cranial and caudal poles of a tumor and typically do not enhance.
Tumoral cysts, on the contrary, typically present within the tumor and
demonstrate peripheral contrast enhancement.
Glial tumors of the spinal cord
Astrocytomas, which are more commonly
seen in children than in adults, are also the most common spinal cord
neoplasms in children. They arise most often in the cervico-thoracic
region, and they generally present with pain and motor dysfunction,
followed by gait disturbance and scoliosis. Most astrocytomas are WHO
grades I and II (75%) that include pilocytic and fibrillary types.
Astrocytomas are infiltrative and eccentric in location, resulting in
asymmetric cord expansion. Cysts, both polar and intratumoral, are a
common feature, occurring 20% to 40% of pediatric cases.
are typically T2-hyperintense, T1-iso- or hypointense, and they may
show patchy, mild-moderate contrast enhancement.2 Enhancement
is less sharply demarcated from the nonenhancing tissue and their
tumoral margins usually extend beyond the enhancing tissue. Unlike
ependymomas, hemorrhage, or calcification is rare with atrocytomas.
Peritumoral edema presents with increased T2 signal in the tumor
periphery, a feature common to all glial tumors. Astrocytomas affecting
the entire cord from the cervicomedullary junction to the conus have
been reported in children, leading to the term “holocord astrocytoma.”3 Cyst
formation extending over several vertebral segments is common, with
associated enhancement of the interspersed solid components (Figure 1).
they are the most common intramedullary glial tumor in adults,
ependymomas are the second most common spinal cord neoplasms in
children. They occur most often in the cervical region with 44%
involving the cervical cord alone and 23% extending into the upper
thoracic region. These tumors arise from the ependymal cells of the
central canal; hence, they are located centrally, as opposed to the
eccentric location of astrocytomas (Table 2). Given the central
location, in proximity to spinothalamic tracts, sensory symptoms are
frequently observed. Almost all spinal cord ependymomas can be
classified as either WHO grade I or WHO grade II.4 Rather than being infiltrative, the tumors are well defined and tend to compress adjacent neural tissue.
Most ependymomas are T1-iso- or hypointense relative to the spinal cord.4-6 They are typically T2 hyperintense relative to the spinal cord,5,6 although in the single largest review of spinal ependymomas, isointense tumors were equally common.5
Tumor margins are usually sharp, and T2-signal alterations correspond
well with the enhancing solid tumor. Ependymomas demonstrate stronger
and more homogenous enhancement than do astrocytomas. Hemorrhage is
common, and the “cap sign,” representing a rim of hemosiderin resulting
from intratumoral hemorrhage, can be seen in the cranial or caudal
margin of the tumor.
ependymoma is a benign ependymoma, composing 40% to 50% of all
ependymomas in adults, but more rarely seen in children. Myxopapillary
ependymomas constitute about 13% of all spinal ependymomas in children
and are more common in males. These tumors typically arise from the
ependymal glia of the conus medullaris and filum terminale. On the basis
of their location, they present with lower back, leg, or sacral pain,
and muscle weakness or sphincter dysfunction. They typically fill the
intradural space, have a lobulated contour, and may result in scalloping
of the posterior vertebral bodies. Myxopapillary ependymomas are
typically T1-isointense and T2-hyperintense relative to the spinal cord
(Figure 2). Internal punctate foci of T1- and T2-hyperintense signal may
be noted, reflecting either mucin content or hemorrhage.6 Avid enhancement with contrast is seen.
Nonglial spinal cord tumors
are low-grade (WHO grade I) tumors composed of well-differentiated
ganglion/neuronal cells, with (ganglioglioma) or without (gangliocytoma)
a glial component. They are most common in children and young adults
with a mean age of 12 years at presentation.7 The tumor
typically originates from the sympathetic chain ganglia and is the most
benign form of neurogenic tumor. T1 signal can be mixed, possibly
secondary to a dual cell population (Figure 3). T2-weighted images are
generally hyperintense. Surrounding edema is not as frequently seen as
with ependymomas or astrocytomas.7,8 Patchy enhancement with contrast is seen, as reported by Patel et al, in 65% of cases.7 Tumoral cysts are more common in gangliogliomas than in astrocytomas or ependymomas.8
cord teratomas are extremely rare neoplasms. Teratomas of the CNS
comprise tissues derived from all 3 germ cell layers; they are
categorized as mature, immature, and malignant Poeze et al observed a
wide age range of patients at presentation; however, in children they
are most often seen in the second decade.9 Demonstrating a
predilection for the lumbosacral spine, the lesions most frequently have
mixed solid and cystic components with fat and calcifications (Figure
4). T1- and T2-hyperintense signal foci are typically seen and
suggestive of fat or calcification. The contrast enhancement pattern
varies, and most teratomas are diagnosed on histopathological
Intramedullary spinal metastases are rare, representing only about 2% of all metastases to the CNS.8 Intramedullary
metastases may result from hematogenous spread or from direct extension
from the leptomeninges. Intradural extramedullary metastases are far
more common than intramedullary metastases in children. Seeding
typically arises from intracranial neoplasms, such as medulloblastomas,
ependymomas, anaplastic astrocytomas, or germinomas. The lumbosacral
spine is typically involved with gravitation of tumor cells and seeding.
Nodular tumoral deposits can be seen anywhere along the leptomeninges.
Thickening of the thecal sac and nerve roots with intense homogenous
contrast enhancement is typical. (Figure 5).
autoimmune, inflammatory or vascular lesions of the spinal cord may
present with neurological symptoms and signs similar to those of tumors.
Non-neoplastic lesions are generally treated medically. MRI remains the
mainstay for differentiating between neoplastic and non-neoplastic
lesions. Non-neoplastic focal spinal cord lesions typically present with
much less cord expansion than do neoplasms. Multifocal involvement
strongly favors non-neoplastic lesions, such as demyelinating diseases.1 Some examples are discussed below.
Acute disseminated encephalomyelitis (ADEM)
is commonly seen late in the course of a viral disease or after
vaccination, and less commonly after a bacterial infection or drug
ingestion. The most common clinical presentation is a focal neurological
deficit that evolves and tends to resolve over a period of weeks. Most
patients make a complete recovery; however, rarely permanent
neurological sequelae can be seen. Recurrent or multiphasic
presentations can be seen. Cases initially diagnosed as ADEM may
eventually be diagnosed as multiple sclerosis.10 White matter
tracts in the brainstem and spinal cord are involved in approximately
50% of all patients. Areas of demyelination present with T1 and T2
prolongation on MRI. Various patterns of enhancement can be seen in the
subacute phase. Every case with suspected demyelinating disease
involving the spinal cord should be complemented with brain MRI.
Multifocal presentation is far more common than unifocal presentation.
Brain imaging reveals involvement of white matter in the subcortical and
periventricular locations both in the supratentorial and infratentorial
brain. Up to 50% of cases demonstrate demyelination in basal ganglia as
Multiple sclerosis (MS)
sclerosis is a demyelinating disease of the CNS, which typically takes a
relapsing-remitting course. MS typically presents between 20 and 40
years of age and is more common in women. Children under age 16 years
make up about 5% of all cases. An MS diagnosis requires multiple
episodes of focal neurologic deficits separated in time and space.10
Typically, multiple foci of demyelinating plaques are seen in white
matter of the spinal cord, with surrounding mild edema. Contrast
enhancement may suggest active demyelination. Brain involvement is seen
in most cases, with bilateral asymmetrical involvement of the
periventricular and subcortical white matter. Demyelinating plaques in
the periventricular white matter and corpus callosum are more commonly
seen in MS than in ADEM.
Idiopathic acute transverse myelitis
acute transverse myelitis (IATM) is an autoimmune myelitis that results
in bilateral motor, sensory, and autonomic dysfunction. MRI findings
are nonspecific and remain a diagnosis of exclusion. MR imaging findings
reveal smooth cord expansion with T1-iso or hypointense signal,
T2-hyperintense signal and variable enhancement with contrast. The top
differential diagnosis of IATM is ADEM, multiple sclerosis (MS),
neuromyelitis optica (NMO), spinal cord infarct, and neoplasm.
cord neoplasms can obstruct cereprospinal fluid flow and mimic
syringohydromyelia. Hydromyelia is characterized by dilatation of the
central canal of the spinal cord (transverse diameter of the canal
exceeds 2 mm). Syringomyelia refers to an eccentric CSF-filled cavity
that may reflect a prior insult to the cord parenchyma. Patients with
first-time diagnosis of syringohydromyelia should have their MR imaging
completed with contrast to rule out the possibility of tumor.
spinal cord lesions in children are rare, with 90% of lesions
representing glial tumors, astrocytomas, and ependymomas. Back pain is a
serious presentation in children and should be appropriately worked up.
The location, degree of cord expansion, enhancement pattern, and
solitary versus multiplicity of lesions help to differentiate neoplastic
from non-neoplastic lesions.
- Huisman TA. Pediatric tumors of the spine. Cancer Imaging. 2009;9(Spec No A):S45-48.
- Constantini S, Houten J, Miller DC, et al. Intramedullary spinal cord tumors in children under the age of 3 years. J Neurosurg.1996; 85:1036-1043.
- Epstein F, Epstein N. Surgical treatment of spinal cord astrocytomas of childhood. A series of 19 patients. J Neurosurg. 1982;57:685-689.
- Fischer G, Brotchi J. Eds. Intramedullary spinal cord tumors. 1st ed. Stuttgart, Germany: Thieme; 1996:60-84.
- Fine MJ, Kricheff II, Freed D, Epstein FJ. Spinal cord ependymomas: MR imaging features. Radiology. 1995;197:655-658.
- Kahan H, Sklar EM, Post MJ, Bruce JH. MR characteristics of histopathologic subtypes of spinal ependymoma. AJNR Am J Neuroradiol. 1996;17:143-150.
- Patel U, Pinto RS, Miller DC, et al. MR of spinal cord ganglioglioma. AJNR Am J Neuroradiol. 1998;19:879-887.
- Koeller KK, Rosenblum RS, Morrison AL. Neoplasms of the spinal cord and filum terminale: Radiologic-pathologic correlation. RadioGraphics. 2000;20:1721-1749.
- Poeze M, Herpers MJ, Tjandra B, et al. Intramedullary spinal
teratoma presenting with urinary retention: Case report and review of
the literature. Neurosurgery. 1999;45:379-385.
- Krupp LB, Banwell B, Tenembaum S, et al. Consensus definitions proposed for pediatric multiple sclerosis and related disorders. Neurology. 2007;68(16 Suppl 2):S7-S12.