Although rare, tumors of the cervical spine are important due to their potentially devastating clinical effects and challenging radiographic appearance. This article will address the clinical, pathologic, and radio-
graphic characteristics of a variety of cervical spine tumors. Knowledge of these characteristics will help radiologists with reasonable differential diagnosis for these tumors.
is a Clinical Instructor of Radiology at Northwestern University
Medical School and a Neuroradiologist at Northwestern Memorial
Hospital, Chicago, IL;
is an Instructor of Radiology at Harvard Medical School and a
Neuroradiologist at Brigham and Women's Hospital, Boston, MA;
is an Associate Professor of Radiology and Assistant Director of
Neuroradiology, Division of Neuoradiology, Brigham and Women's
Tumors of the cervical spine are relatively rare, but are of
great importance due to their potentially devastating clinical
effects and their challenging radiographic appearance. This article
will address the clinical, pathologic, and radiographic
characteristics of a variety of cervical spine tumors. These tumors
are subdivided according to their point of origin: intramedullary,
intradural-extramedullary, and extradural. Although this
classification occasionally may be inexact owing to the propensity
for some spinal tumors to traverse compartments,
it provides a convenient and meaningful framework by which to
approach the majority of cervical spine tumors.
Intramedullary tumors include gliomas (ependymomas,
astrocytomas, and gangliogliomas), and nonglial tumors (such as
hemangioblastomas, lymphoma, and metastases). Gliomas account for
the majority (90% to 95%) of intramedullary spinal cord tumors.
Ependymomas are the most common intramedullary neoplasm in
adults and usually occur in the cervical region.
These lesions arise from ependymal cells that line the central
canal and therefore tend to be central in location with respect to
the spinal cord. Ependymomas tend to produce symmetric spinal cord
expansion and usually have solid and cystic components. Cysts can
be intratumoral, located within the solid tumor, or peritumoral
("polar"), occurring at the cranial or caudal aspects of the tumor.
These cysts are not specific for ependymomas and can be seen with
astrocytomas and gangliogliomas. Intratumoral cysts should be
resected with the solid tumor, as they may contain tumor cells
However, polar cysts do not contain malignant cells
and, therefore, need not be resected; although they may be drained
surgically, they usually decompress spontaneously upon removal of
the solid component.
Ependymomas are characterized by slow growth, and compress
rather than infiltrate adjacent spinal cord tissue, generally
yielding a cleavage plane that aids in surgical resection.
Almost all spinal cord ependymomas are low grade, classified as
either grade I or grade II by the World Health Organization (WHO);
malignant ependymomas are quite rare.
On magnetic resonance imaging (MRI), ependymomas are generally iso-
to hypointense on T1-weighted images and hyperintense on
T2-weighted images (Figure 1). The solid components of ependymomas
usually enhance avidly, although the degree of enhancement may vary
In addition, ependymomas can hemorrhage, resulting in the "cap
sign," a hypointense rim at the periphery of the tumor on
T2-weighted imaging that is related to hemosiderin deposition from
Astrocytomas are the second most common intramedullary neoplasm
in adults, although they are the most common in children.
Astrocytomas result from neoplastic transformation of astrocytes.
In contradistinction to ependymomas, astrocytomas are located
eccentrically within the spinal cord. The vast majority of spinal
cord astrocytomas in adults are of low malignancy, classified
either as pilocytic (grade I) or low-grade astrocytomas (grade II),
although anaplastic astrocytomas and glioblastomas rarely occur.
However, spinal cord astrocytomas tend to infiltrate the cord and
are, therefore, difficult to resect completely.
Astrocytomas are typically iso- to hypointense on T1-weighted
imaging and hyperintense on T2-weighted imaging. They generally
demonstrate patchy, irregular enhancement and have poorly defined
margins. Like ependymomas, they can have intratumoral or polar
cysts but do not tend to hemorrhage and, therefore, do not usually
display a cap sign.
Rarely, astrocytomas arise following radiation therapy, either
for a primary central nervous system lesion, or for a lesion
occurring outside the spine (Figure 2). There are no specific
imaging findings for radiation-induced astrocytomas, and the main
differential for these lesions is tumor recurrence (if there was a
spinal cord tumor present initially) or radiation necrosis.
The literature suggests that radiation-induced astrocytomas tend to
be of a higher grade than idiopathic astrocytomas.
Gangliogliomas are composed of a mixture of ganglion cells and
neoplastic glial elements; the majority of neoplastic glial cell
types are of the astrocytic subtype.
These tumors tend to have a low malignant potential, slow growth,
and a relatively good prognosis.
Gangliogliomas are most common in children and young adults, with a
mean age of 12 years at presentation.
Gangliogliomas tend to be extensive on presentation, occupying an
average length of 8 vertebral segments, compared with ependymomas
and astrocytomas, which average 4 vertebral segments in length.
Like astrocytomas, gangliogliomas tend to be eccentrically located
within the spinal cord.
Tumoral cysts are more common in gangliogliomas than in either
astrocytomas or ependymomas.
Chronic bony changes, including scoliosis and erosions, are often
seen with gangliogliomas due to their relatively slow growth; these
are rarely seen with ependymomas or astrocytomas.
T1 signal characteristics of gangliogliomas are most often mixed,
possibly secondary to the fact that gangliogliomas have a dual cell
population composed of ganglion cells and glial elements.
T2 signal characteristics of gangliogliomas are generally
hyperintense, although surrounding edema is not as commonly seen as
with ependymomas or astrocytomas.
The majority of gangliogliomas show patchy enhancement.
Other tumors of the glioma series such as oligodendrogliomas,
pleomorphic xanthoastrocytomas, and dysembryoplastic
neuroepithelial tumors are extremely uncommon in the adult spinal
Hemangioblastomas are nonglial, highly vascular neoplasms of
unknown cell origin that occur in the posterior fossa and spinal
In the spine, they are most commonly located in the subpial aspect
of the dorsal cervical spine.
They may extend exophytically into the subarachnoid space and have
been reported in the extradural space.
Most spinal hemangioblastomas occur sporadically, but approximately
one-third of cases occur in association with von Hippel-Lindau's
; in patients with this syndrome, hemangioblastomas are often
multiple, and this necessitates screening of the entire spine with
T1-weighted sagittal images (Figure 3). Hemangioblastomas are
hypointense to isointense on T1-weighted imaging and hyperintense
on T2-imaging and enhance homogeneously following gadolinium.
Due to the vascularity of the lesion, prominent flow voids may be
seen with MRI. Spinal hemangioblastomas
may be associated with syringes that are usually more extensive
than those seen with ependymomas or astrocytomas.
Primary intramedullary spinal lymphomas are extremely rare, with
only 15 cases reported in the literature.
These tumors are of the non-Hodgkin variety and can occur in both
and immunocompetent patients.
The majority of these tumors occur in the cervical or thoracic
regions of the spinal cord.
They are solid tumors without necrosis that, on MR imaging,
demonstrate marked T2 prolongation and enhance following gadolinium
Clinically, these patients initially respond to steroid treatment
for a short time,
but like primary lymphomas of the brain, the tumors usually recur
Intramedullary spinal metastases are rare and represent
approximately 2% of all metastases to the central nervous system;
these usually involve the cervical cord.
The most common primary tumors that metastasize to the spinal cord
include lung, breast, colon, lymphoma, and kidney
; rarely, intramedullary spinal cord metastasis may be the initial
presentation of the malignancy.
The prognosis for patients with intramedullary spinal cord
metastasis is poor; two-thirds of patients die within
On MRI, intramedullary spinal cord metastases are T1-hypointense,
T2-hyperintense, and demonstrate homogeneous enhancement
(Figure 4). As with metastases to the brain, the amount of
surrounding edema is out of proportion to the size of the lesion.
Since the arachnoid is essentially continuous with the dura in
the spine, intradural lesions are located in the subarachnoid
space. Intradural-extramedullary tumors include benign lesions
(such as meningiomas and schwannomas) and metastatic lesions.
Spinal meningiomas have similar characteristics to intracranial
meningiomas. They have a strong female predominance with a peak
occurrence in the fifth and sixth decades.
The cervical spine is the second most common intraspinal location
for meningiomas; these more often arise in the thoracic region.
Typically, these lesions demonstrate T1 and T2 signal that is
isointense with the spinal cord and display intense homogeneous
enhancement following gadolinium administration
(Figure 5). A dural tail may be seen, reflecting tumor spread or
reactive changes in the dura adjacent to the tumor. These lesions
are generally pathologically benign, and although they may exert
considerable mass effect upon the spinal cord, symptoms may be
relatively mild due to their slow growth.
Schwannomas are eccentric, exophytic nerve sheath tumors that
are most common in the lower thoracic spine and lumbar spine.
Schwannomas are usually moderately hyperintense on T2-weighted
imaging, but may contain foci of T2 shortening centrally, likely
relating to dense areas of collagen and Schwann cells.
They are slightly hyperintense on noncontrast T1-weighted images
and generally show homogeneous enhancement. Schwannomas rarely
undergo malignant transformation; zones of fluidic signal within
these tumors usually represent cystic degeneration, not
Neurofibromas generally occur in association with
neurofibromatosis (especially NF-1) and can occur at any level of
the spine. They are usually dumbbell-shaped lesions that may expand
the neural foramina and demonstrate homogeneous enhancement. They
are generally isointense on T1 and slightly hyperintense on
T2-weighted images. Like schwannomas, these masses follow the
course of the nerve from which they arise and, therefore, usually
have intradural and extradural components. However, unlike
schwannomas, neurofibromas are tumors of the nerves themselves and
cannot be removed without destroying the function of the parent
Metastasis to the dura may arise from a variety of primary
malignancies, most commonly breast cancer, lung cancer, and
melanoma. Tumors of the central nervous system (glioblastoma
multiforme and posterior fossa ependymomas) may produce "drop
metastases." These metastatic lesions usually appear as small,
round, multifocal lesions that enhance and stud the surface of the
cord. Lymphomatous metastases, on the other hand, tend to produce a
more diffuse pial enhancement, as may breast and prostate
metastases. In a patient with metastatic disease, these
radiographic appearances generally indicate
extramedullary-intradural disease. It should be noted, however,
that multiple cerebral spinal fluid analyses are far more sensitive
than imaging studies in the determination of this process.
Extradural lesions may arise from bone, fat, vessels, lymph
nodes, or the surrounding extramedullary neural elements within the
epidural space. Benign osseous lesions include osteochondroma and
aneurysmal bone cyst. Malignant osseous lesions include
osteosarcoma, chordoma, non-Hodgkin's lymphoma, multiple mye-loma,
and metastatic disease.
Osteochondromas are benign osseous lesions composed of
cancellous bone surrounded by cortical bone and contain marrow
They are developmental lesions, rather than true neoplasms.
They most commonly affect the appendicular skeleton, but can affect
the spine in 2% of cases, most commonly involving the cervical
Osteochondromas are usually exophytic pedunculated lesions but can
be sessile, and they almost always arise from the posterior
elements of the vertebral bodies.
Malignant transformation occurs in 1% of solitary osteochondromas
and in 3% to 5% of patients with hereditary multiple exostoses.
If an osteochondroma undergoes continued growth in the adult
patient, becomes painful, or recurs after resection, the
possibility of malignant degeneration into an osteosarcoma or
chondrosarcoma should be considered.
Enlargement of the cartilagenous cap after skeletal maturity is a
relatively sensitive indicator of malignant transformation. On MRI,
osteochondromas are heterogeneous due to various degrees of
maturity and calcification in the areas of enchondral ossification,
and the cartilagenous cap demonstrates T1 hypointensity and T2
hyperintensity, reflecting its high water content.
Aneurysmal bone cysts
Aneurysmal bone cysts are pathologically benign lesions that are
expansile, lytic lesions filled with chronic blood products. They
have a predilection to occur within the posterior elements of the
spine but may also occur in the vertebral bodies.
They classically appear multiloculated with heterogeneous
fluid-fluid levels within the loculations, reflecting hemorrhage
These lesions may enhance heterogeneously. The most concerning
aspect of aneurysmal bone cysts is their propensity to undergo
pathologic fracture; even trivial trauma to these lesions may
result in fracture with spinal cord compression.
Chordomas are malignant tumors that arise from remnants of the
notochord that travels through the central vertebral bodies. These
lesions have a 2:1 male predominance
with a mean age of 50 years at presentation.
They most commonly involve the sacrum but may also involve the
clivus and upper cervical spine.
In the cervical spine, chordomas tend to be midline in location,
sparing the posterior elements.
They are destructive, locally aggressive lesions that may be
associated with prominent exophytic soft-tissue masses.
As they enlarge, they tend to involve adjacent vertebral bodies and
extend into the adjacent paraspinal tissues and epidural space;
they may even grow into and expand neural foramina, potentially
mimicking nerve sheath tumors.
Uncommonly, they can arise solely in the musculature of the
perivertebral space, presumably from extraosseous notochordal
Chordomas are low to intermediate in signal on T1 and classically
demonstrate significant T2 prolongation
due to the presence of their signature physaliferous cells (clear
cells with intracytoplasmic vacuoles and abundant mucin).
These lesions enhance heterogeneously following gadolinium
and have amorphous calcifications in 50% to 75% of cases
(Figure 6). Chordomas generally have a poor prognosis due to local
recurrence following resection.
Multiple myeloma is a malignancy characterized by monoclonal
proliferation of malignant plasma cells.
Multiple myeloma may involve any level of the spine. On plain film
or CT, they usually appear as focal lytic lesions, but often the
disease may present innocuously, appearing only as diffuse
osteopenia. On MRI, myeloma deposits are multifocal, well-defined
lesions that demonstrate
T1 hypointensity and T2 hyperintensity with respect to normal
Plasmacytomas are large, focal myeloma deposits that may show
gadolinium enhancement. These lesions are expansile lytic masses
that may extend into the epidural space; as with other tumors of
the spine, they may undergo pathologic fracture (Figure 7).
Lymphoma of the spine most commonly involves the extradural
(Figure 8). It generally presents as a solid lesion that
demonstrates T1 isointensity and T2 hypointensity. The T2 signal
characteristics are related to the fact that lymphomas have a high
nuclear-to-cytoplasmic ratio. Moreover, some authors have shown
that because lymphomas are highly cellular tumors with a reduced
extracellular matrix, there is more restricted diffusion on
diffusion-weighted images than is seen with other tumors, such as
Lymphomas demonstrate robust enhancement and may narrow the spinal
canal, resulting in compression of the spinal cord. Accurate
diagnosis is of particular importance with lymphomas, since
radiation therapy can result in rapid reduction in the size and
compressive effects of these lesions.
Metastases to bone
Metastases to bone generally present as T1-hypointense and
T2-hyperintense lesions that replace normal marrow. Pathologic
fractures can be difficult to differentiate from benign
osteoporotic fractures. However, osteoporotic fractures more
commonly cause anterior wedging and the abnormal signal tends to
spare the pedicles and posterior processes, in contradistinction to
metastatic lesions. In addition, benign compression fractures may
be associated with a well-defined linear signal abnormality across
the vertebral body
and tend to reveal sparing of the marrow interspersed within the
affected vertebrae. The most common metastases to bone include
those from cancers of the breast, prostate, lung, as well as renal
cell carcinoma and melanoma.
Tumors of the cervical spine can be classified according to
their location: intramedullary, intradural-extramedullary, and
extradural. Consideration of the location of cervical spine tumors,
as well as their signal characteristics, growth patterns, and
clinical associations, can lead the radiologist to arrive at a
reasonable differential diagnosis for tumors occurring in this