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Lateral Meningocele
KEY FACTS
TERMINOLOGY
• Lateral thoracic meningocele, lateral lumbar meningocele
IMAGING
• CSF-filled dural/arachnoidal sac protrudes laterally through
neural foramen
• Pedicular erosion, foraminal enlargement, dural dysplasia
• Bilateral meningoceles: Consider neurofibromatosis type 1
(NF1), Marfan syndrome
TOP DIFFERENTIAL DIAGNOSES
• Nerve sheath tumor
Congenital and Genetic Disorders
• Radicular (meningeal) cyst
• Foregut duplication cyst
PATHOLOGY
• Etiology secondary to primary meningeal dysplasia
○ Strong association with NF1 (85%)
○ Less common with Ehlers-Danlos, Marfan syndromes
(Left) Axial graphic depicts a
large left lateral thoracic
meningocele ſt producing
pedicular erosion st,
transverse process
remodeling, and widening of
the neural foramen. (Right)
Axial T2WI MR (Marfan
syndrome) demonstrates a
large left lateral thoracic
meningocele ſt extending
through an enlarged,
remodeled neural foramen.
The contiguous intraspinal
extradural component of the
meningocele displaces the
thecal sac anteriorly.
○ Occasionally isolated finding
• Scalloping of pedicles, laminae, and vertebral bodies
adjacent to meningocele
• Enlarged central spinal canal, neural foramina
CLINICAL ISSUES
• Asymptomatic (most common) or nonspecific motor or
sensory symptoms referable to cord/nerve root
compression
• Most remain asymptomatic unless very large or scoliosis
causes symptoms
○ Most static in size; occasionally grow slowly
○ Very large meningoceles may → respiratory
embarrassment (meningocele fills hemithorax)
DIAGNOSTIC CHECKLIST
• Lateral meningocele prompts search for history/stigmata of
NF1 or connective tissue disorder
120
(Left) Axial NECT following
myelography
(neurofibromatosis type 1)
reveals a large left lateral
lumbar meningocele ſt and
extensive vertebral scalloping
from dural dysplasia ,
resulting in marked left
pedicular erosion and
enlargement of the ipsilateral
neural foramen. (Right) Axial
T2WI MR (neurofibromatosis
type 1) shows a large left
lateral lumbar meningocele
ſt in conjunction with
extensive dural dysplasia,
vertebral remodeling , and
marked left pedicular erosion.
Lateral Meningocele
TERMINOLOGY
Synonyms
• Lateral thoracic meningocele, lateral lumbar meningocele
IMAGING
General Features
• Location
○ Thoracic > lumbar spine
○ R > L; 10% bilateral
– Bilateral meningoceles usually associated with
neurofibromatosis type 1 (NF1) but may be seen in
Marfan syndrome
• Size
○ Typical size 2-3 cm; range from tiny to huge
• Morphology
○ CSF signal/density "cyst" adjacent to spine
– Contiguous with neural foramen
– ± sharply angled scoliosis at meningocele level
CT Findings
• CECT
○ CSF density mass extends through enlarged neural
foramen
○ No enhancement; useful to distinguish from nerve
sheath tumor, nerve inflammation (CIDP)
• CTA
○ ± aortic aneurysm, dissection in context of systemic
connective tissue disorder
• Bone CT
○ Wide neural foramen; ± pedicular thinning, posterior
vertebral scalloping (usually)
○ Reformatted images may show focal scoliosis (coronal
plane) and dural ectasia (sagittal plane)
MR Findings
• T1WI
○ CSF signal intensity (hypointense) mass in contiguity with
thecal sac; pedicular thinning, neural foraminal widening
± posterior vertebral scalloping
• T2WI
○ CSF signal intensity (hyperintense) mass in contiguity
with thecal sac; rarely see neural elements within
meningocele
• T1WI C+
○ No enhancement; distinguishes from nerve sheath
tumor or inflammation (CIDP)
Ultrasonographic Findings
• Grayscale ultrasound
○ Posterior mediastinal or lumbar hypoechoic paraspinal
cystic mass contiguous with expanded spinal canal
– Displaces and compresses adjacent spinal cord
○ Ultrasound is primary diagnostic tool in utero, screening
newborn infants
• Pulsed Doppler
○ No vascular flow pattern
• Color Doppler
○ Avascular hypoechoic mass
Congenital and Genetic Disorders
Imaging Recommendations
• Best imaging tool
○ MR
• Protocol advice
○ Consider sonography for newborn screening; follow-up
with MR to clarify positive ultrasound study; MR for
diagnosis, preoperative planning; bone CT to evaluate
pedicles, vertebral bodies (particularly if surgery is
contemplated)
DIFFERENTIAL DIAGNOSIS
Nerve Sheath Tumor
• Less hyperintense than CSF on T2WI, higher signal intensity
than CSF on T1WI
Radicular (Meningeal) Cyst
• CSF signal intensity/density cyst within neural foramen
○ Cyst separate from dural sac, unlike meningocele
Foregut Duplication Cyst
• Bronchogenic most common; may contain gastrointestinal
mucosa
• Proximity to spinal canal ± vertebral anomalies =
neurenteric cyst
PATHOLOGY
General Features
• Etiology
○ Meningocele 2° to primary meningeal dysplasia
– Meningeal weakness permits dural sac to focally
stretch in response to repetitive CSF pulsation →
enlarged neural foramina
– Secondary osseous remodeling permits further
herniation
○ Posterior vertebral scalloping with dural dysplasia →
same etiology
• Associated abnormalities
○ Occasionally isolated finding
○ ± coexistent lumbar and thoracic lateral meningoceles
○ ± findings specific to hereditary disorder
– NF1: Dural ectasia, nerve sheath tumors, CNS
neoplasms, pheochromocytomas, interstitial
pulmonary fibrosis, skin, and subcutaneous
neurofibromas
– Marfan syndrome: Dural ectasia, vascular
dissection/aneurysm, lens dislocation, joint laxity
• Dural sac diverticulum, pedicular erosion, neural foraminal
widening, and posterior vertebral scalloping
Gross Pathologic & Surgical Features
• Scalloping of pedicles, laminae, and vertebral bodies
adjacent to meningocele
• Enlarged central spinal canal, neural foramina
• Cord position variable; usually displaced away from
meningocele
• Scoliosis convex toward meningocele
121
Neurofibromatosis Type 1
KEY FACTS
TERMINOLOGY
• Synonyms: von Recklinghausen disease, peripheral
neurofibromatosis
• Mesodermal dysplasia with neurofibromas (NFs), spinal
deformity, neoplastic and nonneoplastic brain lesions, and
cutaneous stigmata
IMAGING
• Kyphoscoliosis ± multiple nerve root tumors, plexiform NF,
dural ectasia/lateral meningocele
• Tumors range from tiny to very large
Congenital and Genetic Disorders
TOP DIFFERENTIAL DIAGNOSES
• Neurofibromatosis type 2 (NF2, central neurofibromatosis)
• Chronic inflammatory demyelinating polyneuropathy
• Congenital hypertrophic polyradiculoneuropathies
PATHOLOGY
• Autosomal dominant
(Left) Coronal graphic of the
cervical spine demonstrates
multiple manifestations of
neurofibromatosis type 1
(NF1), including a large
intramedullary spinal cord
tumor and bilateral
brachial plexus plexiform
neurofibromas st. (Right)
Sagittal T2WI MR
demonstrates a large
expansile intramedullary
primary spinal cord neoplasm
ſt expanding into the
brainstem. A large neoplastic
syrinx is present. Note also
cervical lordosis reversal,
probably secondary to
laminectomy for cord biopsy.
• Characteristic lesion is plexiform NF, although 3 types of
spinal NF seen in NF1
○ Localized NF (90% of all NF)
○ Diffuse NF
○ Plexiform NF (pathognomonic for NF1)
CLINICAL ISSUES
• Pigmentation anomalies (café au lait, axillary freckling, Lisch
nodules)
• Focal or acute angle kyphoscoliosis ± myelopathy
• Palpable spinal or cutaneous masses
DIAGNOSTIC CHECKLIST
• Multiple nerve sheath tumors, ≥ 1 NF, bizarre kyphoscoliosis
with deformed vertebra → consider NF1
• Absence of visible stigmata does not exclude NF1
• Characteristic plexiform NF imaging appearance best
displayed using fat-saturated T2WI or STIR MR
122
(Left) Coronal STIR MR reveals
extensive plexiform
neurofibromas st involving
the bilateral paraspinal
sympathetic chains, as well as
involvement of multiple
intercostal nerves ſt. (Right)
Sagittal STIR MR obtained offmidline demonstrates
innumerable T2 hyperintense
plexiform neurofibromas
involving the spinal nerves,
sympathetic chains, bilateral
brachial plexus, as well as
multiple cutaneous nerves.
Neurofibromatosis Type 1
TERMINOLOGY
Abbreviations
Neurofibromatosis type 1 (NF1), nerve root neurofibroma
•
(NF), plexiform neurofibroma (PNF), malignant peripheral
nerve sheath tumor (MPNST)
Synonyms
• von Recklinghausen disease, peripheral neurofibromatosis
Definitions
• Autosomal dominant mesodermal dysplasia characterized
by PNFs and nerve root NFs, spinal deformity, neoplastic
and nonneoplastic brain lesions, and cutaneous stigmata
Congenital and Genetic Disorders
Nuclear Medicine Findings
• PET
○ FDG standard uptake value MPNST > benign tumors
Imaging Recommendations
• Best imaging tool
○ MR
• Protocol advice
○ Radiography to quantitate and follow kyphosis, scoliosis
○ Multiplanar enhanced MR (especially STIR, fat-saturated
T2WI, and T1 C+ MR) to evaluate cord, nerve pathology
○ Bone CT to optimally define osseous anatomy for
surgical planning
IMAGING
General Features
• Best diagnostic clue
○ Kyphoscoliosis ± multiple nerve root tumors, PNF, dural
ectasia/lateral meningocele
• Location
○ Entire craniospinal axis
• Size
○ Tumors range from tiny to very large
• Morphology
○ Kyphosis/kyphoscoliosis often severe and bizarre
○ Neurogenic tumors localized to nerve roots as well as
within plexiform nerve masses, cutaneous lesions
Radiographic Findings
• Radiography
○ Kyphosis/scoliosis, scalloped vertebra, hypoplastic
pedicles and posterior elements, "ribbon" ribs
CT Findings
• NECT
○ Hypodense fusiform or focal nerve root enlargement ±
heterogeneous spinal cord expansion (glial tumor)
○ Dural ectasia ± CSF density lateral meningocele(s)
• CECT
○ Variable mild/moderate tumor enhancement
• Bone CT
○ Vertebral findings similar to radiography; canal,
foraminal widening 2° to dural ectasia ± spinal cord
tumor
MR Findings
• T1WI
○ Nerve root NF: Intramedullary glial cord tumors hypo- to
isointense to normal spinal cord, nerve roots, muscle
• T2WI
○ Nerve root NF: Cord tumors hyperintense to normal
spinal cord, nerve roots
– Target sign (hyperintense rim, low/intermediate signal
intensity center) suggests neurogenic tumor; PNF >
NF > MPNST
• STIR
○ Nerve root NF: Cord tumors hyperintense to normal
nerve root, cord, muscle
• T1WI C+
○ Variable mild to moderate NF, cord tumor enhancement
DIFFERENTIAL DIAGNOSIS
Neurofibromatosis Type 2 (Central
Neurofibromatosis)
• Multiple intracranial schwannomas and meningiomas,
spinal schwannomas and meningiomas
• Spinal deformity uncommon
• Clinical, laboratory, and genetic testing findings distinguish
from NF1
Chronic Inflammatory Demyelinating
Polyneuropathy
• Repeated episodes of demyelination, remyelination →
"onion skin" spinal, peripheral nerve enlargement
• Mimics PNF on imaging studies
• No cutaneous stigmata of NF1
Congenital Hypertrophic Polyradiculoneuropathies
• Charcot-Marie-Tooth, Dejerine-Sottas disease
• Nerve root enlargement mimics PNF on imaging studies
• No cutaneous stigmata of NF1
PATHOLOGY
General Features
• Etiology
○ Postulated that NF1 tumor suppression gene "switched
off" → tissue proliferation, tumor development
• Genetics
○ Autosomal dominant; chromosome 17q12, penetrance
→ 100%
– NF gene product (neurofibromin) is tumor suppressor
○ ~ 50% new mutations (paternal germ line; paternal age
35 years → 2x ↑ in new mutations)
• Associated abnormalities
○ Brain abnormalities: Macrocephaly, focal areas of signal
abnormality, sphenoid wing dysplasia, glial tumors,
intellectual handicap, epilepsy, hydrocephalus,
aqueductal stenosis
○ ↑ risk of other neuroendocrine tumors
(pheochromocytoma, carcinoid tumor), chronic
myelogenous leukemia
○ Congenital bowing, pseudoarthrosis of tibia and
forearm, massive extremity overgrowth
○ ↑ fibromuscular dysplasia, intracranial aneurysms,
multiple sclerosis
• PNF is hallmark of NF1
123
Neurofibromatosis Type 1
• Kyphoscoliosis is most common NF1 osseous abnormality;
variable severity mild, nonprogressive → severe curvature
○ Dystrophic scoliosis: Short segment, sharply angulated, <
6 spinal segments, tendency → severe deformity
○ Nondystrophic scoliosis: Similar to adolescent idiopathic
curvature, usually 8-10 spinal segments, right convex
○ Severe cervical kyphosis highly suggestive of NF1
• Dural ectasia: 1° bone dysplasia, some cases 2° pressure
erosion from intraspinal tumors
• "Ribbon" ribs 2° to bone dysplasia ± intercostal NF
Staging, Grading, & Classification
• Consensus Development Conference on
Congenital and Genetic Disorders
Neurofibromatosis (NIH, 1987)
○ 2 or more of the following criteria
– > 6 café au lait spots measuring ≥ 15 mm in adults or 5
mm in children
– ≥ 2 NFs of any type or ≥ 1 PNF
– Axillary or inguinal freckling
– Optic glioma
– 2 or more Lisch nodules (iris hamartomas)
– Distinctive osseous lesion (sphenoid wing dysplasia,
thinning of long bone ± pseudoarthrosis)
– 1st-degree relative with NF1
Gross Pathologic & Surgical Features
• 3 types of spinal NF recognized in NF1
○ Localized NF (90% of all NF)
– Most common NF in both NF1, non-NF1 patients
– Cutaneous and deep nerves, spinal nerve roots
– NF1: Larger, multiple, more frequently involve large
deep nerves (sciatic nerve, brachial plexus)
– Malignant transformation rare
○ Diffuse NF
– Infiltrating subcutaneous tumor; rarely affects spinal
nerves, majority (90%) unassociated with NF1
○ PNF (pathognomonic for NF1)
– Diffuse enlargement of major nerve trunks/branches
→ bulky rope-like ("bag of worms") nerve expansion
with adjacent tissue distortion
– Commonly large, bilateral, multilevel with predilection
for sciatic nerve, brachial plexus
– ~ 5% risk malignant degeneration → sarcoma
Microscopic Features
• Neoplastic Schwann cells + perineural fibroblasts grow
along nerve fascicles
○ Collagen fibers, mucoid/myxoid matrix, tumor, nerve
fascicles intermixed
○ S100-positive, mitotic figures rare unless malignant
degeneration
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Skeletal deformity common (25-40%)
– Focal or acute angle kyphoscoliosis ± myelopathy
– Extremity bowing or overgrowth
○ Palpable spinal or cutaneous mass
○ Pigmentation anomalies (café au lait, axillary freckling,
Lisch nodules) ≥ 90% NF1 patients
124
• Clinical profile
○ Severity of clinical appearance highly variable
○ Classic NF1 triad: Cutaneous lesions, skeletal deformity,
and mental deficiency
Demographics
• Age
○ Childhood diagnosis; minimally affected patients may be
diagnosed as adults
• Gender
○ M = F
• Ethnicity
○ ↑ frequency in Arab-Israeli populations
• Epidemiology
○ Common (1:4,000)
Natural History & Prognosis
• Kyphosis, scoliosis frequently progressive
• NF growth usually slow; rapid growth associated with
pregnancy, puberty, or malignant transformation
Treatment
• Conservative observation; intervention dictated by clinical
symptomatology, appearance of neoplasm
• Surgical resection of symptomatic localized NF, spinal cord
tumors
• PNF invasive, rarely resectable; observation ± biological or
chemotherapeutic (thalidomide, antihistamines,
maturation agents, antiangiogenic drugs) intervention
• Spinal fusion reserved for symptomatic or severe
kyphoscoliosis
DIAGNOSTIC CHECKLIST
Consider
• Multiple nerve sheath tumors, ≥ 1 NF, bizarre kyphoscoliosis
with deformed vertebra → consider NF1
• Absence of visible stigmata does not exclude NF1
Image Interpretation Pearls
• Characteristic PNF imaging appearance best displayed
using fat-saturated T2WI or STIR MR
SELECTED REFERENCES
1. Nguyen R et al: Characterization of spinal findings in children and adults with
neurofibromatosis type 1 enrolled in a natural history study using magnetic
resonance imaging. J Neurooncol. 121(1):209-15, 2015
2. Pourtsidis A et al: Malignant peripheral nerve sheath tumors in children with
neurofibromatosis type 1. Case Rep Oncol Med. 2014:843749, 2014
12(1):1-11, 2010
4. Wasa J et al: MRI features in the differentiation of malignant peripheral
nerve sheath tumors and neurofibromas. AJR Am J Roentgenol.
194(6):1568-74, 2010
5. Scalzone M et al: Neurofibromatosis type 1 clinical features and
management. Pediatr Med Chir. 31(6):246-51, 2009
6. Van Meerbeeck SF et al: Whole body MR imaging in neurofibromatosis type
1. Eur J Radiol. 69(2):236-42, 2009
Neurofibromatosis Type 1
Congenital and Genetic Disorders
(Left) Sagittal T1WI MR shows
extensive intradural
extramedullary neurofibromas
ſt located ventral to the
spinal cord, displacing the cord
posteriorly. Numerous
subcutaneous soft tissue
neurofibromas are also
present posteriorly (several
indicated with st). (Right)
Axial T1 C+ MR of the upper
cervical spine demonstrates
marked extent of involvement
by innumerable soft tissue and
spinal neurofibromas. Note
severe spinal cord
compression produced by
bilateral C2 neurofibromas ſt.
(Left) Coronal STIR MR reveals
innumerable plexiform
neurofibromas involving the
bilateral spinal nerves,
sympathetic chains, and
bilateral brachial plexus, as
well as extensive involvement
of multiple intercostal nerves.
(Right) Coronal STIR MR
depicts bilateral thoracic
nerve root neurofibromas ſt,
extending through the neural
foramina into the paraspinal
tissues. Neurofibromas are
moderately hyperintense on
STIR MR.
(Left) Coronal STIR MR
demonstrates multiple
bilateral lumbar nerve root
neurofibromas ſt extending
through the neural foramina
into the adjacent paraspinal
soft tissues. Small plexiform
neurofibromas st of the
sympathetic chain are also
detected. (Right) Lateral
radiograph of the cervical
spine depicts bizarre acute
angle cervical kyphosis with
marked dural ectasia and
neural foraminal enlargement
, highly characteristic of
NF1.
125
Neurofibromatosis Type 2
KEY FACTS
TERMINOLOGY
• Rare autosomal dominant disease from chromosomal 22
defect in which all patients develop CNS tumors
• Mnemonic for NF2 tumors: Multiple inherited
schwannomas, meningiomas, and ependymomas (MISME)
TOP DIFFERENTIAL DIAGNOSES
• Metastases
• Hemangioblastomas
• Nonsyndromic schwannoma
• Nonsyndromic meningioma
Congenital and Genetic Disorders
• Nonsyndromic ependymoma
• Lymphoma
PATHOLOGY
• 22q12 deletion correlates with loss of NF2 gene product
"merlin" (a.k.a. schwannomin)
• Definite diagnosis of NF2
○ Bilateral CNVIII (vestibular) schwannomas
(Left) Sagittal graphic
illustrates multiple rounded
schwannomas (brown) ſt
along the cauda equina, as
well as flat dural-based
meningiomas (red)
impinging the conus. (Right)
Axial T1WI C+ MR shows
bilateral cerebellopontine
angle masses due to vestibular
schwannomas in this patient
with neurofibromatosis type 2
(NF2).
○ 1st-degree relative with NF2 and either unilateral early-
onset vestibular schwannoma (age < 30 years) or any 2:
Meningioma, glioma, schwannoma, juvenile posterior
subcapsular lenticular opacity
• Presumptive diagnosis of NF2
○ Early-onset unilateral CNVIII schwannomas (age < 30
years) and 1 of the following
○ Meningioma, glioma, schwannoma, juvenile posterior
subcapsular lenticular opacity
○ Multiple meningiomas (> 2) and unilateral vestibular
schwannoma
○ Or 1 of these: Glioma, schwannoma, juvenile posterior
subcapsular lenticular opacity
DIAGNOSTIC CHECKLIST
• Screen using MR C+ of brain and entire spine
• Imaging follow-up of patients with spinal tumors should be
based on knowledge of tumor location, number, and
suspected histologic type
126
(Left) Sagittal T1WI C+ MR
demonstrates multiple
intramedullary enhancing
ependymomas. The largest is
at the C3-C5 level, with
associated inferior cyst, with a
smaller 2nd tumor at C7-T1
level. (Right) Axial T1 C+ MR
shows heterogeneous
enhancement of paraspinal
schwannomas , as well as
an intradural extramedullary
tumor with a broad dural base
consistent with meningioma
ſt.
Neurofibromatosis Type 2
TERMINOLOGY
Abbreviations
• Neurofibromatosis type 2 (NF2), nonsyndromic (NS)
Synonyms
• Bilateral acoustic neurofibromatosis, central
neurofibromatosis (both obsolete)
Definitions
• Autosomal dominant disease from chromosomal 22 defect
in which all patients develop CNS tumors
• Mnemonic for NF2 tumors: Multiple inherited
schwannomas, meningiomas, andependymomas (MISME)
IMAGING
General Features
• Best diagnostic clue
○ Multiple spinal tumors of various histologic types
MR Findings
• T1WI C+
○ Schwannomas: Enhance intensely; homogeneously when
small, heterogeneously when large and cystic
○ Meningiomas: Enhance intensely (often to lesser degree
than schwannomas) and homogeneously
○ Ependymomas: Enhancing, centrally located mass
DIFFERENTIAL DIAGNOSIS
Metastases
• Cord lesions tend to have extensive edema
• Eccentrically placed, rarely within center of cord
Hemangioblastomas
• Often associated with von Hippel-Lindau
• Originate from leptomeninges, associated cyst
Nonsyndromic Schwannoma
• Focal, usually solitary lesion
Nonsyndromic Meningioma
• Isolated dura-based mass
Nonsyndromic Ependymoma
• Usually solitary, with imaging identical to syndromic tumors
Lymphoma
• May coat spinal cord surface
PATHOLOGY
General Features
• Etiology
○ Chromosomal 22 deletion with eventual inactivation of
merlin functionality
• Genetics
○ Inherited autosomal dominant syndrome
○ 22q12 deletion correlates with loss of NF2 gene product
"merlin" (a.k.a. schwannomin)
Staging, Grading, & Classification
• Definite diagnosis of NF2
○ Bilateral CNVIII (vestibular) schwannomas
Congenital and Genetic Disorders
○ 1st-degree relative with NF2 and either unilateral early
onset vestibular schwannoma (age < 30 years) or any 2 of
the following
– Meningioma, glioma, schwannoma, juvenile posterior
subcapsular lenticular opacity
• Presumptive diagnosis of NF2
○ Early-onset unilateral CNVIII schwannomas (age < 30
years) and 1 of the following
– Meningioma, glioma, schwannoma, juvenile posterior
subcapsular lenticular opacity
○ Multiple meningiomas (> 2) and unilateral vestibular
schwannoma or 1 of the following
– Glioma, schwannoma, juvenile posterior subcapsular
lenticular opacity
• 3 features of intramedullary ependymomas
○ Central location within cord parenchyma
○ Intense enhancement
○ Multiplicity, often too many to count
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Nearly half initially present with hearing loss
○ Up to 45% with extramedullary tumors exhibit
signs/symptoms of cord compression
– Varies depending on location
– Weakness and sensory loss at or below level
– Spasticity, pain, loss of bowel/bladder control
Demographics
• Age
○ Genetic disease present at conception
○ Become symptomatic 2nd-3rd decades
• Epidemiology
○ 1 in 50,000 live births worldwide
○ Intradural spinal tumors are present in up to 65% of
patients at initial presentation for imaging
– 84% have intramedullary tumors
– 87% have intradural extramedullary tumors
Natural History & Prognosis
• Many have relatively normal lifespans
• Few patients require therapeutic intervention for
intramedullary tumors, which often remain quiescent
• Intradural extramedullary tumors frequently lead to
surgical intervention
○ Percentage of patients with extramedullary tumors who
undergo surgery is about 5x higher than percentage of
patients with intramedullary tumors
○ Higher surgical rate is result of high number of tumors
and frequent occurrence of cord compression
○ Schwannomas are present more often and in higher
numbers than meningiomas and have more surgical
procedures overall
○ Meningiomas account for disproportionate number of
symptomatic lesions
Treatment
• Tumor resection is mainstay of NF2 treatment
127
(Left) Axial T1WI C+ MR of the
brain reveals bilateral
vestibular schwannomas ſt
and a left trigeminal
schwannoma st, confirming
the diagnosis of NF2. (Right)
Parasagittal T1WI C+ MR of
the cervical spine shows
enhancing foraminal
schwannomas ſt.
Congenital and Genetic Disorders
(Left) Sagittal T1 C+ MR of the
lumbar spine in a typical case
of spinal NF2 demonstrates
numerous nodules arising
within the cauda equina with
avid tumor enhancement,
characteristic of schwannoma.
(Right) Sagittal T1WI C+ MR of
the lumbar spine shows
enhancement of multiple
intradural masses scattered
along the cauda equina,
characteristic of schwannoma.
Neurofibromatosis Type 2
128
(Left) Axial T1WI C+ MR of the
cervical spine shows both
intramedullary ependymoma
enhancement ſt and an
intradural extramedullary
lesion , which is a
schwannoma. (Right) Axial
T1WI C+ MR of the lumbar
spine demonstrates the origin
of the schwannomas to be
from the cauda equina nerve
roots.
Neurofibromatosis Type 2
Congenital and Genetic Disorders
(Left) Sagittal T1WI C+ MR
shows multiple intradural
extramedullary masses at
the cervicomedullary
junction, reflecting a mixture
of meningioma st and
schwannomas ſt. There is
also an enhancing
intramedullary ependymoma
. Recurrent meningioma is
seen at the parietooccipital
junction . (Right) Sagittal
T1WI MR shows a "swan
neck" deformity from prior
multilevel laminectomy.
Multiple intramedullary
lesions within the spinal cord
are biopsy-proven
ependymomas , vaguely
seen as slightly diminished
signal. Meningioma is also
present at skull base ſt.
(Left) Sagittal T1WI C+ MR
shows multiple enhancing
intramedullary masses
throughout the cervical and
thoracic cord due to
ependymomas in this
patient with NF2. Note the
enhancing meningioma at
the foramen magnum ſt.
Patient shows severe "swan
neck" deformity as
complication of prior
multilevel laminectomies for
tumor resection. (Right)
Sagittal T2WI MR shows
variable signal intensity from
the multiple intramedullary
tumors throughout the
cervical and thoracic cord in
this patient with NF2. These
vary from near isointense
to hyperintense st signal.
Meningioma is also present
at the foramen magnum,
seen as a near-cord
isointense signal ſt. "Swan
neck" deformity is present
from prior multilevel
laminectomy with significant
narrowing of subarachnoid
space at the laminectomy
site.
129