University Of Arkansas For Medical

A Comprehensive Review of Intracranial Chordomas
Eren Erdem, M.D., Edgardo J.C. Angtuaco, M.D., Muhammad Husain, M.D., Ossama Al-Mefty, M.D.
University of Arkansas for Medical Sciences, Little Rock, Arkansas
Introduction
Cranial chordomas are relatively
rare, aggressive and locally
destructive tumors of the skull
base. 35% of all chordomas occur
along the vicinity of the clivus
(sphenooccipital bones). They
represent 1% of intracranial and
4% of all primary bone tumors.
Chordomas may occur at any age
but are usually seen in adults with a
peak incidence in the 4th decade of
life with a male predominance of 2:1.
Although generally slow growing, the
tumors’ intimate relation to critical
structures and extremely high local
recurrence rate has led to most
of the patients dying from the
primary intracranial disease. Recent
advances in skull base surgery
and radiation therapy provides an
opportunity for cure. This can be
achieved with precise knowledge of
tumor extent and its relationship to
vital neural and vascular structures
provided by advanced imaging
capabilities of computed
tomography (CT) and magnetic
resonance imaging (MRI).
Tumor Spread
Imaging
Characteristic Imaging Features
CT
MRI
Chordomas present a
lobulated tumor having
a pushing margin and
sharp pseudoencapsulated appearance
(Fig. 2). Such a
demarcation from normal
tissue is not present in
bone where they infiltrate
along the lines of least
resistance. Trabecular
bone is entrapped
leading to dystrophic
calcifications (Fig.3).
The classic CT appearance
is a centrally located wellcircumscribed expansile soft
tissue mass arising from the
clivus with associated extensive
lytic bony destruction (Fig. 6).
T1-Weighted
Chordomas are intermediate to low signal on
T1-W images and are easily recognized within
high intensity fat of clivus (Fig. 8). Small foci of
hyperintensity can sometimes be visualized in the
tumor correlating to intratumoral hemorrhage or
mucous pool (Fig. 9-24).
Fig. 2- T2
-weighted
MR image
shows tumor
septations
and pseudoencapsulated
appearance.
2
Fig. 3- CT of
skull base
demonstrates
infiltration of
tumor into the
clivus and
pre-pontine
cistern leading
to trabecular
entrapment and
dystrophic
calcification.
3
Cranial chordomas most often
originate from the sphenooccipital
synchondrosis of the clivus.
They may also involve the
upper (basisphenoid) or lower
(basiocciput) clivus (Fig. 4).
6C
Intratumoral calcification seen
on CT appears irregular and
is thought to represent the
bony sequestra from destroyed
bone (Fig. 7A). Chondroid
variant is most likely to show
real intratumoral calcification
(Fig. 7B).
Occasionally they arise from the petrous apex
(Fig. 5).
Fig. 5– Unenhanced CT
(A) shows lytic lesion
of the petrous apex
Enhanced axial
T1-weighted MR (B)
demonstrates strongly
enhancing mass in the
right petrous apex with
extension into the
adjacent cavernous
sinus and sella.
CT and MRI are required in the pretreatment
evaluation. Their unique location at the skull
base and their proximity to critical soft tissue
structures makes critical assessment necessary.
7A
14A
Fig. 8- Unenhanced MR studies of two patients. Axial
T1-weighted MR (A) shows small hypointense mass within
the right side of the clivus. Sagittal T1-weighted MR (B)
shows large hypointense soft tissue mass from the distal
clivus with anterior extension into the nasopharynx and
extradural extension into the posterior fossa.
Fig. 9- Sagittal
unenhanced
T1-weighted MR shows
rim of hyperinintensity
along a posteriorly
projecting retroclival
mass indicative of highly
proteinaceous material
or blood products.
T2-Weighted
The classical chordoma is extremely high signal on
T2-W images (Fig. 10) which likely reflect the high
fluid content of vacuolated cellular components.
T2-W images are superior in separating tumor
from contiguous neural structures (Fig. 11). Areas
of hypointensity and heterogenous signal are
the result of calcification, hemorrhage and highly
proteinaceous mucous pools (Fig. 12).
10B
14B
13A
Fig.13– Unenhanced axial T1-weighted MR (A) shows
isointense mass along right side of clivus and petrous
apex. On enhanced studies (B) there is marked diffuse
homogeneous enhancement of the mass.
Fig. 15– Axial enhanced
T1-weighted MR shows variable
enhancement (honeycomb
appearance) of a large midclival
mass with extension to the sella
and adjacent cavernous sinuses.
Note lateral displacement of right
cavernous internal carotid artery.
18B
Fig. 10– T2-weighted MR images of chordomas in different patients show (A)
homogeneous diffuse hyperintensity; (B) heterogenous hyperintensity most likely due
to small mucous lakes; (C) Diffuse hyperintensity of tumor in clivus with intradural
extension into posterior fossa.
Fig. 18– MR studies (A,B) demonstrate a mass extending
to the left middle cranial fossa (A) with suprasellar
extension (B). Left carotid angiogram (C) show narrowing
of the distal left internal carotid artery and upward
displacement.of the left middle cerebral artery.
Fig. 17– Coronal
T1-weighted MR (A)
shows tumor extension
to the right cavernous
sinus with
displacement and
partial encasement of
the cavernous internal
carotid artery.
Composite image of
MRA (B) shows
posterior
displacement of the right posterior cerebral artery.
Sagittal T1-weighted MR (C) demonstrates posterior
and superior elevation of the right cavernous internal
carotid artery.
Fig. 7– Sagittal CT reformation (A)
reveals bony sequestra at the distal
end of the lytic clival lesion.
Unenhanced CT (B) shows
intratumoral calcification adjacent to
lytic clival lesion.
Fig. 19– Sagittal unenhanced
T1-weighted MR (A) show mass involving
the posterior fossa with large extracranial
soft tissue extension to the face. The
recurrent tumor on left external carotid
arteriogram (B) demonstrate tumor
vascularity from branches of the posterior
auricular artery.
19B
Fig. 28– Surgical resection
through midline
transmaxillary approach.
Sagittal and axial MR before
(A, C) and after surgery (B, D)
reveal complete resection of the
clival and intradural extension
of tumor (arrows).
Local
28B
28A
4
3
3-Inferior
Fig. 32– Initial studies (A) shows mass
primarily in sellar area. Transmaxillary
approach to tumor was done and
postsurgical MR a year after surgery
showed recurrent tumor at the site of
the surgical approach: in the nasal
region (B) and in the clival area (C).
29A
posterior
fossa
1- Dahlin DC, Mac Charty CS: Chordoma. A study of 59 cases. Cancer 5: 1170-1178 (1952)
2- Raffel C, Wright DC, Gutin PH, Wilson CB. Cranial chordomas: Clinical presentation and results of
operative and radiation therapy in twenty-six patients. Neurosurgery 17: 703-710 (1985)
3- Al-Mefty O,Borba LAB: Skull base chordomas: a management challenge. J Neurosurgery 86:
182-189 (1997)
4- Oot RF, Melville GE. The Role of MR and CT in evaluating clival chordomas and
chondrosarcomas.AJR 151:567-575 (1988)
5- Larson TC, Houser W, Laws ER. Imaging of cranial chordomas. Mayo Clin Proc 62:886-893
(1987)
6- Doucet V, Viton PP, Branger DF,et al. MRI of intracranial chordomas. Extent of tumor and contrast
enhancement: criteria for differential diagnosis. Neuroradiology 39:571-576 (1997)
Fig. 31– Massive intra-and extracranial recurrence
of chordoma in a 14 year old patient referred
from an outside institution following an initial
partial resection. Note extensive soft tissure
recurrence with extension in the posterior fossa
and retropharyngeal space.
Recurrence remote from the origin along surgical pathway
is a known feature (Fig. 32).
Fig. 29– Surgical
resection through
cranioorbitozygomatic
approach (arrows).
Presurgical MR (A)
Postsurgical MR (B)
show radical resection
of the tumor.
3-Posterior
31C
Surgical Pathway
2-Lateral
middle cranial
fossa
nasopharynx
31A
28D
cavernous sinus
References
19A
Post-surgical follow up is best achieved with MRI.
28C
17C
Angiographic evaluation is nonspecific and abnormal tumor vascularity
or stain is rare (Fig. 19).
Fig. 12– T2-weighted MR
demonstrates multiseptated
hyperintense mass with
extension into the sella and
left cavernous sinus. Mass
exhibits variable signal
intensity with areas of
hypointensity.
1 2
3rd ventricle
17B
Angiography
Fig. 11– T2-weighted MR
shows well demarcated
hyperintense mass with
anterior extension into the
sella and left ethmoid sinuses
and lateral extension to the
right middle cranial fossa,
compressing the uncus.
chiasm
4-Superior
17A
Aggressive surgical removal followed by high dose
radiation is the most effective treatment. Recurrence
free survival rate at 5 years is about 55-65% following
combined surgical-radiation therapy.
1-Anterior
Tumor displacement (Fig. 16) or partial encasement (Fig. 17) of
intracranial arteries is often visualized. Arterial narrowing is rare with
chordomas, which may correlate with the observation these tumors are
generally soft and easily dissected from adjacent vessels (Fig. 18).
Fig. 16– IVI
reprojection of a
magnetic resonance
angiogram (MRA) of
the vertebrobasilar
artery delineates
superior and
posterior
displacement of
vertebrobasilar
junction by large
clival chordoma.
Recurrence
31B
Magnetic Resonance Angiography
10C
7B
orbit & nasal cavity
sphenoid sinus
13B
Fig. 14– Sagittal unenhanced T1-weighted MR (A)
shows large isointense soft tissue mass in distal
clivus exhibiting little to no enhancement on enhanced
studies (B).
18A
10A
5B
8B
6B
notochord
remnants
5A
Fig. 1- Histologic slide showing
vacuolated cells with intracytoplasmic
mucous droplets (physaliferous
appearance) typical of chordoma
Fig. 6– CT scans
of different cases
showing lytic lesions
of the: (A) mid-clivus;
(B) distal clivus with
involvement of
adjacent occipital
condyles; (C) distal
clivus with associated
soft tissue
nasopharyngeal
mass.
6A
Location
Histopathology
Chordomas are neoplasms of
vestigial notochord tissue. Remnants
of the notochord may remain in
the midline, usually entrapped within
bone along the ends of the spinal
column. Clivus and coccyx serve as
the main site of origin of chordomas.
The tumor cells tend to be arranged
in cords set in a pale matrix of mucopolysaccharide with characteristic
physaliferous appearance (Fig 1).
8A
Enhanced Studies
Moderate to marked enhancement is very common (Fig. 13)
but, not the rule (Fig. 14).
Sometimes a honeycomb pattern
of enhancement can also be
seen (Fig. 15).
Treatment
Fig. 30– Presurgical
evaluation of petrous apex
chordoma. Presurgical MR
studies (A, B) demonstrate
right petrous apex mass
with extension to foramen
lacerum and occlusion of
petrous internal carotid
artery. Presurgical
angiograms (lateral
projections) confirms
occlusion of right internal
carotid artery on a right
common carotid arteriogram
(C) and collateral filling of
the branches of the right
internal carotid circulation
with associated dysplastic
aneurysm of the right
posterior communicating
artery on a left vertebral
angiogram (D). With detailed
knowledge of the lesion
gained from imaging studies,
total tumor resection and
clipping of the aneurysm
were achieved (E, F).
30A
32A
32B
29B
32C
30B
Distant Metatasis
30C
30D
30E
30F
Fig. 33– Postsurgical axial CT
(A) shows a soft tissue mass
in the left infratemporal fossa
(surgical approach). Axial CT of
the thoracic spine (B) with bone
and soft tissue settings show
metastatic destructive lesion in
the left pedicle with adjacent soft
tissue extension. This represents
distal metastatic spread of
chordoma.
33A
33B
Conclusion
Intracranial chordomas are rare, midline tumors of clival
origin. MRI and CT imaging are the modality of choice
for diagnosis, treatment planning and follow up. Bone
destruction and the presence of intratumoral calcification
is visualized on CT, and MR imaging delineates soft tissue
extension and the relation of the tumor to vital structures
and intracranial vessels. Radical surgical resection
followed by proton beam radiation therapy achieves the
best results. Local recurrence is not uncommon with an
unfavorable prognosis.