INFRATENTORIAL BRAIN TUMORS
David I. Sandberg, M.D.
- Approximately 50% of tumors in children older than one year of age are
infratentorial (46, 47).
- The relative incidence of the most common infratentorial tumors in the
pediatric population is outlined in Table 1. Table 2 lists less common
infratentorial tumors found in children.
- Epidemiological features associated with each of the most common
subtypes, as well as intrinsic tumors of the brainstem, are outlined
below in Section VI (Classification and Management of Specific Tumor
Table 1: Relative Incidence of the Most Common Infratentorial Brain
Tumors by Histology (Excluding Intrinsic Brainstem Tumors) in Children
Tumor Histology | Percentage of Tumors
Medulloblastoma (PNET) | 30-55%
Cerebellar Astrocytoma | 25%
Ependymoma | 20%
Table 2: Uncommon Posterior Fossa Tumors in Children (34)
Choroid Plexus Pappilloma
Metastasis (most common: neuroblastoma, embryonal rhabdomyosarcoma, Wilms
- Presentation varies significantly depending upon the patient’s
age, the tumor’s location within the posterior fossa, and
histological tumor classification.
- •The most common presenting signs and symptoms are those
associated with elevated intracranial pressure from hydrocephalus:
headache, nausea, vomiting, and lethargy.
- Infants may present with macrocrania and a full fontanelle or with more
subtle findings such as irritability, failure to thrive, and loss of
- Infants may also present with torticollis.
- Additional presentations include gait abnormality, other cerebellar
signs such as dysmetria, or cranial neuropathies.
- Progression of tumors is typically more rapid for malignant tumors,
such as medulloblastoma, than benign tumors, such as pilocytic
General Management Principles
Preoperative Imaging Studies:
- MRI scan with and without gadolinium contrast is the imaging study of
- MRI scan of the total spine should be obtained preoperatively to rule
out the presence of leptomeningeal disease, which may affect surgical
management. It may be difficult to distinguish between leptomeningeal
disease and surgical debris or blood products on postoperative spine MRI.
Management of Hydrocephalus Prior to Tumor Resection:
- Dexamethasone administration: (0.5-1 mg/kg IV loading dose, up to 10
mg, then 0.25-0.5 mg/kg/day IV or PO divided q6 hours) accompanied by an
antacid for gastrointestinal protection, admission to an intensive care
unit, and timely tumor resection.
- Ventriculostomy placement for lethargy, bradycardia, or neurological
deterioration. Avoid rapid decompression of the ventricles and risk of
upward herniation during ventriculostomy placement. Set no lower than 15
cm of H2O above the external auditory meatus.
- Endoscopic Third Ventriculostomy (ETV) Prior to Tumor Resection: This
is an area of current controversy. May reduce the incidence of
postoperative hydrocephalus (59). However, only a minority of children
require CSF diversion after tumor resection (20).
- Shunt Placement: Not currently recommended.
Management of Hydrocephalus After Tumor Resection:
- Permanent CSF diversion after complete or near-complete tumor resection
is usually not required.
- Need for postoperative shunt placement more likely to be required in
younger patients and those with large tumors, large ventricles, or
long-standing ventriculomegaly (32).
- Relative indications for shunt placement (or possibly ETV)
postoperatively include large ventricles associated with symptoms of
elevated intracranial pressure, progressive ventriculomegaly on
postoperative imaging studies, enlarging pseudomeningocele, and CSF
Other Preoperative Considerations:
- Any child with symptomatic hydrocephalus or rapidly progressive
neurological changes associated with an infratentorial tumor should be
admitted to an intensive care unit.
- Dexamethasone should be started (0.5-1 mg/kg IV loading dose, up to 10
mg, then 0.25-0.5 mg/kg/day IV or PO divided q6 hours).
- Antacid for GI protection.
- Any relevant systemic medical issues should be addressed and the
patient should be prepared for surgery as soon as possible.
- MRI scan of the brain and total spine are obtained within 24 hours
- Surgery is generally performed within 24 hours thereafter. Patients
with lethargy or rapidly progressive symptoms may require immediate
operative intervention, and those without hydrocephalus and an indolent
presentation may be treated more electively.
- Type and cross blood. May need FFP and platelets for large or malignant
- Admit to an intensive care unit for hourly neurological checks, close
monitoring of vital signs, and laboratory examinations as needed.
- An urgent CT scan should be obtained for progressive lethargy or
neurological changes in the immediate postoperative period to look for
hemorrhage or acute hydrocephalus.
- A postoperative MRI scan of the brain should be obtained within 48 to
72 hours after surgery, if possible, because enhancement thereafter may
not represent residual disease (47).
- If the postoperative MRI demonstrates a complete or near complete tumor
resection, and postoperative edema is not extensive, dexamethasone can be
tapered over approximately 7 days.
- Infratentorial tumors require surgical resection to establish the
histological diagnosis and to reduce or eliminate the tumor burden.
- Exceptions include diffuse brainstem gliomas, which do not require
biopsy and are not surgically resectable, and intrinsic tectal gliomas,
which can be observed with treatment only for associated hydrocephalus
General Intraoperative Considerations
- Positioning: In general, prone position with chest and hip rolls placed
to avoid abdominal compression.
- Pin fixation is typically used to maintain head position. Caution
should be taken when placing pins in young children or in patients with
long-standing hydrocephalus who may have a thin cranium.
- Younger children and infants may be positioned in a padded horseshoe
with caution taken to avoid pressure on the face or eyes.
- While head flexion is helpful for surgical exposure, breath sounds and
airway pressures should be checked carefully after positioning to ensure
that the endotracheal tube has not been kinked.
- Blood Loss: can be rapid and life-threatening.
- Extreme caution must be taken when opening the
dura in the posterior fossa, particularly in young children who may have
enlarged dural venous sinuses.
- Tumor bleeding during resection can also be
extensive, particularly for malignant tumors such as medulloblastoma.
- All patients should have an arterial line and
appropriate venous access. In the event of extensive blood loss,
coagulopathy and thrombocytopenia should be ruled out and aggressively
corrected if diagnosed.
Midline Suboccipital Craniotomy: the common surgical procedure
performed for children with infratentorial tumors. The basic surgical steps
for a midline suboccipital craniotomy for tumor resection are outlined below:
- Neurophysiological monitoring: is controversial. Most useful in
patients with lateral tumors involving the cerebellopontine angle or
focal tumors intrinsic to the brainstem.
- Prolonged Postoperative Intubation: May be considered for patients who
require long operations, receive multiple units of blood, or who have
extensive manipulation of cranial nerves and may not be able to protect
Other Surgical Approaches: Cerebello-pontine angle tumors in
children, such as ependymomas, may be approached via a retrosigmoid approach
as reviewed by Sanford et al. (61) . Focal brainstem tumors are best
approached by the route which provides the shortest trajectory to the tumor.
Surgical approaches to various areas within the brainstem are detailed in
other references (52).
- Midline incision from the external occipital protuberance to below the
spinous process of C2.
- Dissection through ligamentum nuchae, a relatively avascular tissue
between the suboccipital muscles, and placement of self-retaining
retractors to move muscles laterally.
- Separation of muscle from the occipital bone, posterior arch of C1, and
superior half of the posterior arch of C2. In infants, dissection over C1
should be especially cautious, as the posterior arch may not be fully
- Wide craniotomy from just below the estimated location of the
transverse sinus to the opisthion.
- Removal of the posterior arch of C1 should be considered, especially
for large tumors with significant inferior extension.
- Dural opening, typically in a Y-shaped fashion, with caution regarding
the presence of enlarged occipital and circular venous sinuses.
- Drainage of CSF from the cistern magna and introduction of the
- Identification of normal vascular structures (vertebral artery and
PICA) and cranial nerves bilaterally.
- Gentle elevation of the cerebellar tonsils to identify the floor of the
fourth ventricle, and placement of a cottonoid paddy if possible to
protect the brainstem and spinal cord.
- Intraventricular tumors which extend far superiorly may require
resection of the inferior portion of the cerebellar vermis to avoid
extensive cerebellar retraction.
- Tumors that extend to the lateral cisterns may be reached using the
cerebellomedullary fissure (telovelar) approach without vermian resection
(30). Tumors located within the cerebellar hemispheres or vermis may be
identified with intraoperative ultrasound, which may facilitate approach
through the least amount of cerebellar tissue.
- Tumors are typically resected using a combination of ultrasonic
aspiration and bipolar coagulation with suction. Orientation regarding
the floor of the fourth ventricle is always maintained to avoid injury to
the brainstem. Small amounts of tumor clearly attached to or invading the
brainstem, or firmly attached to cranial nerves, are not resected.
- Intraoperative ultrasound may be useful at the conclusion of tumor
resection to confirm the extent of tumor resection.
- Primary dural closure after tumor surgery in the posterior fossa is
usually difficult, and duraplasty with pericranium or dural substitutes
is usually performed.
- Replacement of bone flap and standard closure of cervical muscles,
fascia, and skin.
Complications of Surgery
- Postoperative hematoma: may be rapidly life-threatening in the
posterior fossa and should be evacuated immediately if large and/or
- Postoperative acute hydrocephalus: may result from cerebellar swelling
or obstruction of CSF pathways by blood products or residual tumor. If
symptomatic, immediate ventriculostomy placement should be performed.
- Vascular injury to PICA, vertebral artery, or transverse sinus.
- Cranial nerve injury (abducens palsy, facial weakness, hearing loss, or
vocal cord paralysis).
- Brainstem injury causing cranial nerve palsy and/or hemiparesis.
- Pseudomeningocele and/or CSF leak. If present postoperatively,
hydrocephalus must be ruled out.
- Cerebellar signs such as nystagmus, ataxia, or dysmetria.
- Refractory nausea/vomiting.
- Posterior Fossa Syndrome (a.k.a. Cerebellar Mutism): typically develops
1 to 4 days after surgery, even after patients initially demonstrate
normal speech postoperatively. The syndrome includes mutism with
emotional lability and possibly other neurological deficits. The mutism
is typically transient and recovers after several weeks, although not
always completely (64). Multiple etiologies have been proposed, but none
have been definitively proven (67).
Classification and Management of Specific Tumor Subtypes
- AKA primitive neuroectodermal tumor of the posterior fossa (PNET).
- The the most common malignant pediatric brain tumor, accounting for
between 15% and 20% of pediatric brain tumors and 30% to 55% of posterior
fossa tumors (34, 54, 57).
- Mean age at presentation is 5 to 7 years, and 80% of patients are
younger than 15 (54).
- More common in males than females, ranging from 1.4 to 1 to greater
than 2 to 1 male to female ratio depending upon the study (8, 25).
- Most commonly presents with signs and symptoms of elevated intracranial
pressure from obstructive hydrocephalus, especially headaches and
vomiting. May also present with cerebellar signs such as trunchal or
appendicular ataxia or cranial neuropathies, especially sixth nerve
palsy. Young children may present with irritability alone, sometimes
associated with macrocephaly or loss of developmental milestones (40).
Presenting signs and symptoms tend to progress rapidly in patients with
- Typically hyperdense on CT scan. Hypointense or isointense on
T1-weighted MRI sequences, hyperintense on T2-weighted sequences, and the
majority enhance, at least partially, with gadolinium (39). Tumors are
typically (although not always) intraventricular, may involve the vermis,
and may invade the brain stem (57).
- Treatment: complete surgical resection if possible, but subtotal
resection should be performed if the tumor is noted at surgery to invade
the brain stem. A small amount of tumor left behind (<1.5 cm2 on
postoperative MRI scan) is not associated with worsened outcome (4).
- Postoperative treatment algorithms are affected by stratification of
patients into high risk and average risk groups, as defined in the table
Table 3: High Risk Versus Average Risk Medulloblastoma (42)
- Age >3 years
- No leptomeningeal seeding (ventricular, spine,
or subarachnoid) by MRI
- Negative CSF cytology (obtained >10 days
- < 1.5 cm2 of residual tumor on post-op
- No extra-neural metastasis (bone, lungs)
- Failure to meet one or more of criteria listed
for average risk
- All patients at least 3 years of age should
receive postoperative external beam radiation therapy (ranging from 2340
cGy to 3600 cGy of craniospinal radiation with a boost to the posterior
fossa, typically to approximately 5400 cGy) in conjunction with
chemotherapy (a variety of regimens have been employed). Reduced dose
radiation therapy can be considered in average risk patients, and reduced
dose radiation or no radiation can be considered in patients under 3
years of age (5, 23, 58, 71).
- Current treatment regimens are associated with 5
year progression-free survival rates as high as 90% in average risk
patients and may even exceed 80% in high risk patients (43). Recurrent
medulloblastoma is associated with a much lower survival rate, with
previous reports of 30% 5 year survival using high-dose chemotherapy with
stem cell rescue (13).
- Survivors have been noted to have an increased
risk of neurocognitive decline, endocrine effects, second malignancies,
and a variety of additional complications associated with both radiation
therapy and chemotherapy (21, 29, 31, 41).
- Third most common pediatric brain tumor, behind astrocytoma and
medulloblastoma, and accounts for 8% to 10% of primary CNS tumors in
children and 20% of posterior fossa tumors (34, 57).
- Tend to occur in younger patients than medulloblastoma. The mean age at
presentation ranges from 3 to 6 years, and approximately 1/3 of patients
are diagnosed before age 3 (19, 27, 45).
- There is no reported sex predominance for patients with ependymoma (56,
- Presenting signs and symptoms are typically related to obstructive
hydrocephalus (57). Nausea and vomiting may be induced by compression of
the area postrema, and signs of cerebellar compression such as ataxia and
nystagmus may be noted (35).
- CT scan typically demonstrates a low density mass in the fourth
ventricle causing hydrocephalus with intense, homogenous contrast
enhancement and possible calcifications and cystic components. Tumors on
MRI are typically hypointense to isointense on T1-weighted sequences,
hyperintense on T2-weighted sequences, and enhance with contrast.
Extension into the lateral recesses of the fourth ventricle may be
- Leptomeningeal seeding is noted in approximately 5% to 10% of patients
at presentation (45, 53).
- Gross total surgical resection should be performed if possible. The
completeness of surgical resection is the single most important
prognostic factor for recurrence-free survival (9, 24). A near-total
resection, defined as less than 1.5 cm2 of residual tumor, may have a
similar prognosis to gross total resection (56). If resectable residual
disease is visualized on postoperative MRI scan, re-ooperation should be
- Postoperatively, even patients with gross total tumor resection should
receive external beam radiation therapy, as receiving radiation therapy
leads to higher rates of recurrence-free survival even after gross total
resection (60). Radiation dose for posterior fossa ependymomas without
leptomeningeal spread of disease is typically 5400 to 6000 cGy
fractionated to the tumor bed. Patients with leptomeningeal disease
should receive cranio-spinal radiation therapy, typically 4500-5000 cGy
- Chemotherapy may be used in children younger than age 3 years of age to
delay radiation therapy, but has not been proven to have benefit to date
beyond delaying radiation therapy in young children (35). A study by the
Pediatric Oncology group demonstrated that, in children less than 3 years
of age, delaying radiation therapy by 2 years after complete resection is
associated with a significantly lower survival rate than if radiation is
delayed 1 year (12).
- Stereotactic radiosurgery can achieve local tumor control and may be
offered at the time of recurrence after maximal safe surgical resection
of recurrent disease (1).
- The 10-year survival rate for patients over 5 years of age at
presentation is approximately 40% to 50% (35, 60). The overall poor
prognosis is due to the fact that long-term survival is so dependent upon
gross total tumor resection, and a total resection can be achieved in
only 50% to 70% of cases (68). Many ependymomas are not safely resectable
because they are firmly attached to multiple cranial nerves or the brain
stem or have leptomeningeal disease at presentation (35). Neurological
deficits, especially cranial neuropathies, are frequently reported after
aggressive surgical resection and may be transient or permanent (68). The
presence of anaplasia has been reported by some others to be associated
with poorer prognosis, while other authors have reported histological
grade to be of no prognostic value (56).
- Patients with disease recurrences have a dismal overall prognosis for
long-term survival, and complete resection is typically more difficult to
achieve at the timie of recurrence (68). Younger patients have a poorer
prognosis overall in many but not all reports (35, 60, 68).
- Comprise approximately 15% of all pediatric brain tumors, 25% of
posterior fossa tumors in children, and over 70% of cerebellar
astrocytomas occur in children (28, 34, 47).
- Mean age at presentation is 7 years, and cerebellar astrocytomas are
rare in children less than age 1 (10).
- No reported sex predominance (11).
- Long history of slowly progressive symptoms, reflecting the relative
indolence of these tumors (10, 28). Most children present with signs and
symptoms of elevated intracranial pressure from gradual obstruction of
the fourth ventricle and resulting hydrocephalus (47). Cerebellar
deficits such as truncal or appendicular ataxia and nystagmus are also
common (10). Younger children may present with macrocrania or regression
of previously achieved motor milestones (70). Rarely present acutely with
intratumoral hemorrhage (38).
- May be cystic with a mural nodule, completely cystic, completely solid,
or mixed cystic and solid (67). The solid portion of the tumor is
typically hypodense or isodense to surrounding cerebellar tissue (18).
The bone windows of CT scans may demonstrate a thin cranium due to
long-standing hydrocephalus. The solid portion of the tumor is typically
hypointense on T1-weighted MRI sequences and hyperintense on T2-weighted
MRI sequences compared with surrounding cerebellum. The solid portion of
tumors typically enhances brightly with contrast on CT and MRI, but cyst
walls often do not enhance (67). Leptomeningeal seeding throughout the
brain and spine is rarely observed (66).
- Most are histologically benign lesions, typically pilocytic
astrocytomas, which can often be cured by surgical resection without any
adjuvant therapy. Gross total resection of all solid and enhancing tumor
portions should be performed, but non-enhancing cyst walls do not need to
be resected. If a cyst wall has thick enhancement, it is likely
neoplastic and should be resected (67).
- Re-operation should be considered for significant residual tumor on
immediate postoperative or subsequent imaging studies, but small amounts
of tumor may be observed because they may remain stable or even regress
spontaneously (11, 63).
- Radiation therapy, either focal conformal or stereotactic radiosurgery,
may be considered for unresectable residual or recurrent tumor which
progresses on serial imaging studies (7, 22).
- Chemotherapy is also an option for recurrent, unresectable cerebellar
astrocytomas, but is only rarely necessary to consider. Malignant
cerebellar astrocytomas are exceedingly rare and are treated with
postoperative radiation therapy and chemotherapy (67).
- Long-term, event-free survival is achieved in the vast majority of
patients after gross total tumor resection, with previously reported 5-,
10-, and 25-year survival rates of 90%, 89%, and 85%, respectively (11,
67). Tumor recurrence occurs in fewer than 10% of patients after gross
total resection, but long-term follow-up is necessary, as extremely late
recurrences, even 36 years postoperatively, have been reported (44, 67).
Most patients have minimal, if any, long-term disability related to tumor
- Comprise between 10% and 20% of all CNS tumors in children (62,
- Mean age at presentation ranges from 7 to 9 years, but patients can
present anytime between infancy and the late teens (6, 16, 33).
- No reported sex predominance (6).
- Brainstem gliomas are typically classified as diffuse, dorsally
exophytic, cervicomedullary, or focal (16). These subgroups which have
distinct presentations, radiographic appearances, treatment options, and
outcomes. Tectal tumors are a distinct type of focal brainstem tumor
which should be considered separately because of their distinct
presentation and management.
Dorsally Exophytic Tumors
- Typically present with rapidly progressive
ataxia, long tract signs, and cranial nerve palsies, which are often
bilateral (17, 37).
- Typically hypointense on T1-weighted MRI and
hyperintense on T2-weighted MRI with heterogenous and often minimal
enhancement. The pons is diffusely expanded by the tumor, and this is
particularly notable on T2-weighted sequences (17).
- Surgical resection is not safe to perform and
biopsy is not indicated. Previous reports of biopsy of these lesions
demonstrated astrocytomas which varied in grade from WHO Grade II to IV,
but tumor histology had no effect on prognosis (2, 3, 17).
- No chemotherapeutic agent to date, either alone
or in combination, has been shown to improve the prognosis in patients
with diffuse brainstem tumors. Conventional external beam radiation
therapy, typically approximately 5400 cGy, improves symptoms temporarily
in the majority of patients (16, 17).
- Prognosis is dismal. Median survival is 11 to
12 months, and only about 10% of patients are alive 2 years after
diagnosis (16, 17).
- Most commonly present with symptoms of obstructive hydrocephalus
similar to other fourth ventricular tumors. Typically benign, and
symptoms progress very gradually. Most patients do not present with
cranial neuropathies. Ataxia is common in older patients, and younger
patients may present with a long history of vomiting and failure to
thrive (26, 49, 65).
- Imaging studies demonstrate a tumor attached to the dorsal surface of
the brainstem filling the fourth ventricle. Typically hypodense or
isodense on CT scan and hypointense on T1-weighted MRI sequences.
Typically enhance homogeneously (26, 48).
- Treatment consists of maximal surgical debulking without violation of
the brainstem. Even if a small amount of residual tumor is present on
postoperative imaging studies, observation without additional treatment
is recommended. Repeat surgery, possibly followed by external beam
radiation therapy, can be considered for disease progression (16,
- A complete tumor resection is usually not achieved. However, only a
minority of patients require additional treatment for tumor progression
(16, 26, 49, 65). Morbidity from surgery includes transient or permanent
cranial nerve deficits, ataxia, nystagmus, or other cerebellar findings
Focal Intrinsic Tumors
- Intra-axial tumors of the cervicomedullary junction are most commonly
low-grade astrocytomas which present with a long history of progressive
neck pain, paresthesias, and weakness due to spinal cord dysfunction.
Alternatively, patients can present with lower cranial nerve dysfunction
from the medullary component of the tumor (14).
- Imaging studies demonstrate a tumor which has a caudal portion
identical in appearance to an intramedullary spinal cord tumor and a
rostral portion which pushes the medulla upward and may produce a bulge
at the level of the obex (15). These tumors may cause obstructive
hydrocephalus, are typically hypointense on T1-weighted MRI sequences,
and have varying enhancement patterns (16, 48).
- Should be surgically resected completely if possible in a manner
similar to intrinsic tumors of the cervical spinal cord. Intraoperative
ultrasonography and monitoring of somatosensory evoked potentials (SSEPs)
and motor evoked potentials (MEPs) are valuable adjuncts (14).
- Postoperative management consists of observation with serial imaging
studies and consideration of re-operation and possible postoperative
radiation therapy for disease progression (48).
- A gross total tumor resection is usually possible, and long-term tumor
control is excellent, with only a 10% to 20% recurrence rate (16). The
extent of motor and sensory deficits as well as cranial nerve dysfunction
is typically directly related to the preoperative neurological status
- Present with progressive cranial neuropathies in association with motor
deficits or other long-tract signs. The specific cranial nerves involved
depend upon the tumor location (26, 48, 69).
- Imaging studies demonstrate tumors limited to one segment of the
brainstem which displace, rather than invade, normal structures. Tumors
are typically hypodense on CT, hypointense on T1-weighted MRI, and have
varying enhancement patterns. T2-weighted MRI sequences show a pattern of
signal abnormality which overlaps completely with signal abnormality
observed on T1-weighted sequences, which helps distinguish focal tumors
from diffuse tumors (48).
- Symptomatic patients may be offered surgical tumor resection via the
route which offers the shortest and safest trajectory to the tumor (52).
Because of the high risk of postoperative neurological deficit for
surgery of focal tumors involving the pons or medulla, the role of
surgery is less established for focal tumors of this region compared with
those involving the pontine tegmentum (48). Surgical procedures are
typically performed with monitoring of SSEP’s, brainstem auditory
evoked responses (BAERs), and relevant cranial nerve electromyography
(EMGs). The goal of surgery is an aggressive subtotal resection with
great care to avoid injury to normal brainstem structures. Residual tumor
may spontaneously involute on follow-up imaging studies (48, 69).
Re-operation and/or radiation therapy may be offered for recurrent
disease (26, 48, 69).
- Most reported series are small, with relatively short follow-up.
Despite subtotal resection, subsequent tumor progression is observed in
only a minority of patients and is typically treated with radiation
therapy. Postoperative neurological deficits are common and are directly
related to preoperative deficits and the aggressiveness of surgical
resection (26, 48, 69).
- A particularly benign subset of focal brainstem tumors that typically
presents with slowly progressive signs and symptoms of obstructive
hydrocephalus such as headache, nausea, and vomiting. Patients may also
present with sixth cranial nerve palsy from elevated intracranial
pressure (36, 50, 55).
- Usually associated with obstructive hydrocephalus on imaging studies.
Typically isointense to brain on T1-weighted MRI sequences, hyperintense
on T2-weighted sequences, and either non-enhancing or minimally enhancing
- Generally indolent lesions which are most commonly clinically and
radiographically stable over many years of follow-up. Ony the associated
hydrocephalus usually requires treatment, and these patients are ideal
candidates for ETV. Patients are followed with periodic MRI scans, but
neither biopsy nor any direct treatment for these tumors is generally
- Long-term survival is expected in all patients with tectal gliomas with
adequate treatment of associated hydrocephalus, and only a small minority
of patients exhibit radiographic tumor progression over time (50).
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