J Korean Neurosurg Soc 34 : 589-592, 2003
KISEP
Case Report
Huge Schwannoma Extended from Craniocervical
Junction to Upper Thoracic Spine
Sung Ho Kim, M.D., Jae Won Doh, M.D.,
Seok Mann Yoon, M.D., Il Gyu Yun, M.D.
Department of Neurosurgery, Soonchunhyang University Chonan Hospital, Chonan, Korea
We report a case of 16 centimeter long schwannoma extended from craniocervical junction to upper thoracic spine that
was successfully resected by posterior laminoplasty. However the patient developed postoperative kyphotic deformity at
3 months postoperatively, and it was corrected by anterior corpectomy and plate fixation.
KEY WORDS : Schwannoma·Long segment·Kyphotic deformity.
Introduction
S
chwannoma is a benign slow growing tumor of nerve
sheaths and can arise on cranial nerves or peripheral
nerves, or anywhere which contains nerve sheaths. At first, it
was named neurilemmoma by Stout in 1935 and was
renamed schwannoma by Ehrlich and Martin in 1943.
Schwannoma accounts for 97.6% of neuromeningeal
tumor13), which is the most common neuromeningeal tumor
of the spinal cord. Most schwannomas are located intradurally and they can involve several vertebral levels, but the
reports of long level schwannoma are very rare. We report a
case of huge schwannoma extending from craniocervical
junction to upper thoracic spine, which was surgically
removed after C1-T2 laminoplasty. After multilevel laminoplasty, swan-neck deformity was developed and it was
corrected by anterior interbody fusion and plate fixation. We
describe rarity of this long schwanomma and possible cause
of cervical kyphosis related to surgery as well as the method
to prevent postoperative cervical instability.
A
B
Fig. 1. Magnetic resonance imaging of the cervical spine demonstrating a long heterogeneously enhancing mass lesion from the
medulla to T1 spinal cord(A). Intradural extramedullary mass‘M’
displacing the spinal cord
‘C’
ventrolaterally is clearly seen(B).
examination revealed decreased pain and temperature
sensation below C2 dermatome on her left side body. There
were no motor or reflex abnormalities. Magnetic resonance
images(MRI) demonstrated a 16 centimeter long intradural
extramedullary mass which extended from medulla to upper
thoracic cord(Fig. 1A). Well marginated enhancing mass
compressed spinal cord on the right dorsal aspect(Fig. 1B).
Case Report
Presentation and examination
A 31-year-old woman was admitted with posterior neck
pain and occipital headache for 3 months. She also
complained radiating pain on her right arm. Neurologic
Received：June 19, 2003 Accepted：August 8, 2003
Address for reprints：JaeWon Doh, M.D., Department of
Neurosurgery, Soonchunhyang University Cheonan Hospital, 23-20
Bongmyung-dong, Cheonan 330-721, Korea
Tel : 041) 570-2184, Fax : 041) 572-9297
E-mail : [email protected]
Operation
The patient underwent suboccipital craniectomy and
laminoplasty from C1 to T2. The dura was very tense. After
opening the cranial and spinal dura, a brownish huge mass
extended from the medulla to T1 spinal cord was exposed. It
was located on the dorsal aspect of medulla and spinal cord
and displacing them ventrally. We resected the tumor
successfully without difficulty because the mass was well
demarcated from the cord and spinal roots, except in the right
C1 nerve root which had severe adhesion. Mass was soft,
friable and had poor vascularity. We totally removed the
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Huge Schwannoma
Fig. 2. Pathologic finding shows spindle
cells with palisading arrangements. In
areas, there are also vacuolar change of
the cytoplasm (H&E stain,×400).
tumor mass and then
performed reconstructive laminoplasty.
The origin of the
tumor was thought
to be the right C1
nerve root which had
severe adhesion.
The histological diagnosis was a typical
schwannoma (Fig. 2).
Postoperative course
Immediately after surgery, radiating pain on her right arm
was subsided and she regained normal sensory function on
her left side of body. At two weeks after surgery, she was
discharged without any neurologic deficit. At postoperative
10 months, she was readmitted with gait disturbance.
Neurologic examination on re-admission revealed weakness(G4/5), decreased sensory function below C5 dermatome
and exaggerated deep tendon reflex on her right side of body
with positive Babinski and Hoffman sign. Voiding and
defecation function was normal.
Plain lateral x-ray of cervical spine demonstrated swanneck deformity(Fig. 3A). MRI of cervical spine showed
spinal cord compression at C4-6 level with kyphotic
deformity(Fig. 3B).
To reduce neural compression and severe kyphosis of
cervical spine, we performed combined anterior and posterior
approach of cervical spine at the same time. At first posterior
A
B
Fig. 3. Plain x-ray(A) and magnetic resonance(MR) image(B) of
cervical spine at postoperative 10 months demonstrating swan-neck
deformity. MR image showing spinal cord compression at C4-6 level.
590 J Korean Neurosurg Soc 34
decompression was
done with C5,6 laminectomy. And then
C4,5 anterior corpectomy and interbody
fusion with mesh cage and plate fixation
was followed. After
the surgery, she promptly regained normal sensorimotor and
ambulatory function.
At present, 22 months postoperatively,
she is normally improved to enjoy climbFig. 4. Plain x-ray of cervical spine after
ing a mountain.
Postoperative plain C4-5 corpectomy and instrumentation
demonstrating correction of swan-neck
lateral x-ray of cervi- deformity.
cal spine revealed correction of swan-neck deformity(Fig. 4).
Discussion
N
erve sheath tumors consist of schwannoma(97.6%),
neurofibroma(2.1%), and malignant peripheral nerve
sheath tumor(0.3%). Nerve sheath tumors account for about
30 per cent of primary intraspinal tumors and schwannoma is
the most common tumor of the spinal cord 2,13). The majority
arise from the dorsal nerve roots of the spinal cords and most
commonly occur on the thoracic spine2). Most are located
intradurally, but 10 to 15 per cent extend through the dural
root sleeve as dumbell tumors with both intradural and
extradural components1,10). About 10 per cent of nerve sheath
tumors are epidural or paraspinal in location. One per cent of
nerve sheath tumors are intramedullary in location and are
believed to arise from the perivascular nerve plexus, mostly
exist along the branches of the anterior spinal artery7,13).
Sridhar et al.12) has classified spinal schwannoma into 5
types based on the radiologic findings. They defined "giant
spinal schwannoma" as tumor that extend over more than two
vertebral levels in length. Although large schwannomas have
been reported in literature4,10,11,13,14), there are few cases with a
huge tumor as our case involving multiple vertebral levels.
Nagasawa et al.9) has reported a giant schwannoma located
between the foramen magnum and fifth thoracic levels, which
was detected by developing hydrocephalus. Schwannoma is
generally slow growing tumor, therefore patients may be
SH Kim, et al.
asymptomatic for years prior to diagnosis9). Radicular pain is
an early symptom and it can be related to compression of a
spinal nerve. The clinical features are variable and are
determined by tumor location. Involvement of upper cervical
spine or foramen magnum region produces disproportionate
loss of position and vibration sensation in the upper
extremities and atrophy of the intrinsic muscle of the hands.
Nystagmus has been attributed to pressure on the sulcomarginal fibers which are an extension of the medial longitudinal
fasciculus. Involvement of the middle and lower cervical
region produces a suspended capelike sensory loss with pain
that involves the upper extrimities. Horner's syndrome may
be seen unilaterally or bilaterally, depending on the degree of
involvement of the sympathetic fiber. Involvement of the
upper thoracic region evokes pain in a girdle-type distribution, sometimes mistaken for angina pectoris or pleurisy.
Tumors at the lumbosacral or conus medullaris can affect the
parasymphathetic innervation of the bladder, bowel, and
sexual organs, therefore enuresis and sexual disturbance may
precede other overt neurologic abnormalities. Involvement of
the cauda equina may selectively impair the function of a
single dorsal root. This leads to persistent discrete dermatomal appreciation of pain which may be mistaken for lumbar
disc prolapse. In our case, even if the tumor mass was huge
and compressed spinal cord severely, there was only radiating
pain and decreased pain and temperature sensation. This
minimal neurologic deficits of our case was due to compensation of spinal cord because schwannoma has a slow-growing
nature.
The MRI findings represent slightly hypointense or isointense on T1WI and hyperintense on T2WI. On enhancement,
homogenous enhancment is a usual finding but often
heterogenous enhancement from intratumoral cysts, hemorrhage, necrosis is possible. Treatment is surgical excision.
However, it is controversial to sacrifice the involved nerve
root when the tumor is derived from a nerve root which is
assumed to be important for extremity functions. Miura et al.8)
reported 10 of 15 patients showed loss of motor function and
8 patients developed sensory impairment after resection of
involved nerve root, but most of them has recovered on
follow up. Therefore they hypothesized that involved nerve
root may have been nonfunctional before operation, and even
when it was functional, it would be compensated by the
neighboring nerve roots. In our case, there was no neurologic
deficit after the involved nerve root was sacrificed.
Katsumi et al.6) has reported the risk factors of cervical
instability resulting from laminectomies for removal of spinal
cord tumor. According to this report the younger patients, the
presence of preoperative kyphotic deformity, laminectomy
more than four laminas, removal of C2 lamina, and
destruction of facet joints are risk factors involved in the
pathogenesis of cervical instability. Incidence of spinal
deformity was observed less frequently with laminoplasty
group than laminectomy group. Laminoplasty is good method
to preserve the function of posterior osseoligamentous
complex, therefore cervical stability is maintained after
laminoplasty procedure. To prevent postoperative cervical
instability, laminoplasty with reconstruction of the erector
spinal muscles and nuchal ligament is recommended for
patients with a cervical cord tumor. When there is a high risk
factor for the development of spinal deformity, even if
laminoplasty was performed, an additional operation is
recommended. Katsumi et al.6) has suggested interbody
fusion should be considered whenever cervical instability is
anticipated. Herman and Sonntag3), recommended anterior
cervical corpectomy and plate fixation for postlaminectomy
kyphosis. In our case, there was postoperative cervical
kyphosis even after reconstructive laminoplasty possibly due
to high risk factors for postoperative instability such as,
younger age(31years), C2 laminectomy and multi-level(9
levels) laminoplasty. However, our patient regained cervical
stability and alignment by anterior corpectomy and plate
fixation. Before performing operation in such case of huge
cervical cord tumor, there should be a careful evaluation of
risk factors of postoperative spinal instability. If there is a
high risk, combined approach such as posterior laminoplasty
and anterior corpectomy with plate fixation is a reasonable
option.
Conclusion
W
ith multilevel laminoplasty for huge craniocervical
cord tumor, it is important to keep in mind the
possibility of swan-neck deformity. To prevent this kind of
complication, we stress anterior cervical fixation in addition
to posterior laminoplasty or laminectomy.
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