Spinal Tumors

Chapter 43Page 509-514

Introductions The advent of MRI has led to widespread recognition of

interadual lesion. It can be difficult to distinguish as interdural

lesion from transverse myelitis, demyelinating condition or other lesion not suitable for surgery.

A carful physical exam can isolate the level of involvement along the spinal cord.

The risk of surgical damage to critically important regions surrounding a lesion must be weighted against risks associated with nonsurgical.

Primary CNS tumor are more common intracranially,

2% to 4% such tumor occur in the spine.Primary CNS tumor of the spine is classified as;- Exteradural- Interadural exteramedullary- Interdural interamedullary.

• an exteradural tumor typically represents a metastasis or lymphoma.

Primary Spinal Tumors

Interadural Exteramedullary Tumor Its account for 60% to 70% of all primary

spinal cord tumors.Most of this tumor are nerve sheet tumor or

meningioma.Patient usually have symptoms related to cord

compression, including local or radicular pain.Patient often report deep seated pain in the

back.

Schwannoma Is a type of nerve sheath tumor.Usually is benign, although malignant

subtype is exist.Commonly originate from dorsal nerve root.The peak incidence is during the forth and

fifth decades of life.They occur equally among male and female.The tumor may be associated with

neurofibromatosis type II

MRI Appearance On MRI, a schwannoma appears as a lesion

arising from the dorsal root.

Some time as dumbbell lesion with both interadural and exteradural components.

T1 weighted MRI image show isointensity

T2-weighted image show marked hyperintinsity.

The contrast enhancement is variable

Other Characteristics Tumor that have existed for long period of time

can erode the neural foramina and scalloping of posterior vertebral body.

Schwannoma occur: 31% in cervical spine 24% in cauda equina, 22% in thoracic spine, 16%upper cervical spine, and 7%. conus medullaris

It can be difficult to distinguish a schwannoma from a neufibroma.

Neurofibroma It originate in the peripheral nerve and tend to

favor the ventral root.

They are classified as general of plexiform.

A solitary general neurofibroma is a discrete well-circumscribed lesion with a fusiform or globular appearance.

The peak incidence is during the fourth and fifth decades of life.

Equal distribution among men and women.

The presence of multiple neurofibromas can suggest neurofibromatosis.

50% of patients with neurofibromatossi type I have a malignant peripheral nerve sheath tumor

Like schwannoma, a neurofibroma appears as a well-circumscribed, rounded or fusiform lesion that may be dumbbell shaped.

The imaging characteristics also are similar Isointensity on T1W-MRI and marked hyper

intensity on T2 w-MRI.With intense contrast enhancement.

T1: hypointenseT2: hyperintense

T1 C+ (Gd): heterogenous enhancement

Meningioma Is a dura-based benign tumor that accounts for

25% of all primary spinal cord tumors.More than 80% of spinal meningiomas are

diagnosed in womenMost tumor occur in thoracic spine. In men, meningiomas occur with equal in the

cervical and thoracic.The peak incidence of these tumors is during the

fifth and sixth decade of life.94% of meningiomas are interadural and 6% are

exteradural.

MRI Appearances It appear as a well circumscribed, dura based

lesion.Tumor is isointense or hypointencse on T1w-MRI On T2 w-MRI slightly hyperintense.Homogenous intense in contras enhancement.Calcification sometimes are present. In contrast with neurofibromas meningiomsa

usually are entirely intradural or exteradural.Multiple meningiomas are particularly associated

with neurofibromatosis type II

Meningeal hemangiopericytoma Is an exteremely rare tumor with only a few

incidences.

Malignant feature are more common than in other types of intradural exteramedullary tumor.

The lesion has lobular appearance on MRI

Heterogeneity on T1 and T2 MRI angiogram reveals corkscrew vessels with an associated tumor blush.

Dermoid and Epidermoid CystsThey arise from abnormal heterotopic presence

of ectodermal cells in the neural tube during embryogenic development.

Approximately 40% of epidermoid cysts in the spine are a late complication of lumbar puncture in which tissue was implanted in the thecal sac.

These lesions usually are found in the lumbosacral spine, although they also can appear in the thoracic region.

Epidermoid cyst typically appear during the fourth decade of life.

Dermoid appear during the third decade. If the lesion rupture chemical meningitis can

ensue.An epidermoid cyst can be difficult to see on

MRI because it consistency is similar to that of cerebrospinal fluid.

Diffusion-weighted MRI can be useful for distinguishing an epidermoid cyst from an arachnoid cyst.

Dermoid cyst contain solid cholesterol, and their signal intensities can be similar to those of fat.

Lipoma Intradural extramedullary lipomas are

congenital.

The typical regions of involvement are the lower thoracic and lumbosacral spine.

A lipoma in the region of the cauda equina can cause tethered cord syndrome.

On MRI Lipoma is hyperintence on T1 and hypointence on T2

T1: hyperintense T2: hypointense

fat-suppressed sequences: hypointense

Paraganglioma Is a nonsecrating tumor derived form

paraganglion cell of the autonomic nervous system.

These tumor are considered benign.The mean age of patinas is 48 years.More men than women are affected.Typically involves the conus medullaris, cauda

equina or filum terminale.

MRI Appearance The signal is hypointense or isointense on T1-

weighted MRI and heterogeneous on T2Hemosiderin deposits on the periphery of the

tumor can appear as a rim of T2-weighted or gradient echo hypointensity.

The infusion of contrast can produce the classic salt-and-pepper appearance.

Intradural Inramedullary Tumors Intramedullary tumors represent 20% to 30% of

all intradural tumors in adults and 50% of intrdural tumors in children.

More than 80% of intramedullary tumors are classified as gliomas.

30% to 40% of intramedullary tumors are classified as astrocytoma's.

60% to 70% are classified as ependymomas.Astrocytoma are more common in children and

ependymomas are more common in adults.

Hemangioblastoma accounts for 3% to 8% of primary intramedullary tumors

This tumor is associated with von Hippel-Lindau disease in 15% to 20% of patients.

Only 2% of intramedullary tumors are of metastatic origin.

The symptoms of the tumor vary with its location.

Local or radicular pain is common.Motor deficits occur in 50% to 69%. Sphincter

dysfunction occur in 64% to 65% Sphincter dysfunction is the initial symptoms in

14% to 38%

Ependymoma Is the most common intramedullary tumor.

Typically classified as cellular or myxopapillary.

Myxopapillary ependymoma accounts for approximately 40% to 50% of spine ependymomas.

Clear-cell, papillary, anaplastic, and mixed variant subtypes also exist.

The incidence of cellular ependymoma peaks during the fourth and fifth decades of life.

Cellular ependymoma represents 40% to 60% of all intramedullary tumors in adult and 16% to 23% in children.

Myxopapillary and cellular ependymoma are histologically distinct.

Cellular ependymoma appear as a focal enlargement of the spinal cord.

The cervical spine affected in 42% of patientsOn MRI is diffuse heterogeneous contrast

enhancement with isointensity or hypointensity on T1 and hyperintesity on T2

Astrocytoma75% of astrocytomas are benign.

They typically occur during the third decade of life.

No preference for men or women.

In children represents as many as 80% to 90% of intramedullary tumors.

MRI AppearancesThis tumor have fusiform appearance on MRI

with irregular margins. Intratumoral, caudal or rostral cysts can evolve

into syringomyelia.The appearance is hypointense to isointense on

T1On T2 is hyperintense, with variable contrast

enhancement. In high grade lesion, there is more prominent

enhancement intratumoral cysts can appear and surrounding edema and necrosis become more obvious.

The tumor is more common in the cervical spine of adults

Hemangioblastoma Is a benign vascular tumor. 10% to 25% are associated with von Hippel-

Lindau disease.Sporadic tumors occur predominantly in men

typically during the fourth decade of life.The tumor favor the dorsal location and thus

tends to affect sensation.Most of this lesion are solitary and are found in

cervical of thoracic spine.

MRI AppearancesMRI reveals a homogeneously enhancing nodule

accompanied by a cyst and sometimes by peritumoral edema or syringomyelia.

Small lesion appears isointense on T1and hyperintense on T2

Large lesion appears isointense to hypointese with T1 and hetrogeneous with T2

Heterogeneous contrast enhancement is seen within the nodule.

Sub EpendymomaFewer than 50 incidence of subependymoma

have been reported.

Predominantly in men in their fourth or fifth decade of life.

Is located in cervical spine and less commonly in the thoracic spine.

A subependymoma mimics a spine ependymoma on MRI

Other Interadural Intermedullary Tumors Oligodendrogalioma 2% located on spine.Ganglioglima LymphomaGerminoma Melanoma Lipoma is a congenital lesion Teratoma Intamedulary metastasis

References: 1- Orthopedic knowledge update spine chapter 432- radiopaedia.org/articles/spinal-nerve-sheath-tumours.3-EUROPEAN SOCIATY OF RADIOLOGY POSTER C-3375