Intracranial neoplasms can be benign or malignant tumors that form within the cranial or spinal cavity. There are two main types - primary tumors that originate from brain cells, and secondary tumors that metastasize from other organs like the lung or breast. Symptoms arise from the tumor infiltrating and compressing brain tissue. Diagnosis involves neuroimaging to identify the mass and contrast enhancement. Treatment options depend on the tumor type, with more invasive tumors requiring surgery and radiation therapy while palliative care is used for metastatic tumors.

1. Intracranial Neoplasms
Dr. Hawar Adnan
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2. Definition
• A cerebral neoplasm can be defined as a
benign or malignant expanding lesion whose
constituent cells multiply without restraint and
form a mass within the cranial or spinal cavity.
• There are two main types:
• (1) primary tumors, made up of astrocytes,
oligodendrocytes, ependymocytes, (together
called gliomas); special arachnoidal fibroblasts
(meningiomas); neuroblasts-medulloblasts
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3. • (2) secondary tumors, which are metastatic
carcinomas from lung, breast, etc., and
lymphomas.
• All of these tumors cause symptoms by
infiltrating, displacing, and compressing brain
tissue and provoking seizures.
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4. Etiology
• Little is known about etiology.
• Familial occurrence is low but not
insignificant.
• EB virus has been implicated in lymphomas of
the brain.
• The age of the patient is also a factor;
medulloblastoma, pilocytic astrocytoma,
pinealoma, optic glioma, and brainstem glioma
are essentially tumors of childhood.
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5. Pathophysiology
• As a group, the gliomas arise in one or a few foci in the
cerebral white matter, central gray matter, brainstem, or
cerebellum. Their borders are inobvious, and they
cannot be completely excised.
• The well-differentiated tumor cells of an astrocytoma
and oligodendroglioma infiltrate and displace the
normal cells and myelinated fibers.
• Undifferentiated glial cells (glioblastoma multiforme,
grade III astrocytoma) proliferate more rapidly, often
outstripping their blood supply and becoming necrotic
and hemorrhagic in places.
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6. • With tumor growth there is compression of
venules in the adjacent cerebral white matter
and a disruption of the blood-brain barrier.
• Plasma proteins seep into the cerebral white
matter, causing vasogenic or localized cerebral
edema.
• As the mass in the cerebrum or cerebellum
increases in size, intracranial pressure rises and
adjacent normal brain is displaced.
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7. • Because of the compartmentalization of the
cranial cavity by dura (falx, tentorium), pressure
from a mass in one compartment causes a shift of
brain tissue into another compartment, where the
pressure is lower.
• The deficits produced by these displacements,
which appear late in the course of tumor growth,
are added to those of the tumor itself.
• This may lead to tissue herniation from one
compartment to another.
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8. Types of Herniation
1. cingulate herniation under the falx
2. downward transtentorial (central) herniation
3. uncal herniation over the edge of the
tentorium,
4. cerebellar tonsillar herniation into the
foramen magnum
• Coma and ultimately death result when (2),
(3), or (4) produces brainstem compression.
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9. Types of Herniation
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10. CLINICAL MANIFESTATIONS
1. Progressive focal neurologic deficits.
2. seizures .
3. “nonfocal” neurologic disorders (headache,
dementia, personality change, gait disorder).
• Nonfocal disorders are due to increased
intracranial pressure (ICP), hydrocephalus, or
diffuse tumor spread.
• Elevated ICP suggested by vomiting,
drowsiness, papilledema, impaired lateral gaze,
headache that intensifies with recumbency.
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11. • Strokelike onset may reflect hemorrhage into
tumor or development of acute hydrocephalus.
• Brain tumors may be large at presentation if
located in clinically silent region (i.e., prefrontal)
or slow-growing .
• frontal, or temporal lobe tumors may present as
psychiatric disorder.
• Systemic symptoms (malaise, anorexia, weight
loss, fever) suggest metastatic rather than primary
brain tumor.
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12. Diagnostic Tests
• Primary brain tumors have no serologic features
of malignancy such as an elevated ESR or tumor-
specific antigens, unlike metastases.
• Neuroimaging (CT or MRI) reveals mass effect
(volume of neoplasm and surrounding edema) and
contrast enhancement (breakdown of blood-brain
barrier).
• CSF exam is limited to diagnosis of possible
meningitis or meningeal metastases but may
cause brain herniation if mass effect or
hydrocephalus present.
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13. Treatment
• Surface tumors such as meningiomas and acoustic neuromas
are amenable to complete surgical removal.
• Meningiomas of the base of the brain may infiltrate bone and
can be excised only partially. Radiation therapy is then given.
• For gliomas, the common practice is excisional biopsy
followed by radiation therapy.
• Symptomatic treatment includes glucocorticoids
(dexamethasone 12–20 mg/d in divided doses) to temporarily
reduce edema; prophylaxis with anticonvulsants for tumors
involving cortex or hippocampus; and low-dose subcutaneous
heparin for immobile pts.
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14. Glioblastoma multiforme
• 20% of all intracranial tumors, 55% of all
gliomas; mainly affect cerebral hemispheres
but may affect all parts of brain and cord.
• It is widely infiltrative ( highly malignant).
• survival is about 12 months in most cases.
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15. Malignant astrocytoma (glioblastoma)
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16. Astrocytomas (low grade)
• 25–30% of cerebral gliomas;
• In adults, common sites are cerebral
hemispheres
• In children, brainstem and cerebellum;
• It is a slowly growing tumor that has a
tendency to form cysts;
• Survival rate is for many years.
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17. Oligodendroglioma
• 5–7% of intracranial gliomas.
• Frontal lobes are the most common sites.
• It is a slowly growing tumor.
• Characteristically forms calcifications.
• Survival for many years if low-grade
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18. Oligodendroglioma
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19. Ependymoma
• Derived from ependymal cells
• Common sites are fourth ventricle (particularly
in children), conus medullaris, and filum
terminale.
• Survival depends on degree of anaplasia
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20. Meningioma
• Extraaxial mass attached to dura; dense and
uniform contrast enhancement is diagnostic.
• 15% of all primary intracranial tumors
• highest incidence occurs in seventh decade;
more frequent in women.
• Very slow growing; symptoms depend on
tumor site.
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21. Meningioma
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22. Primary CNS lymphoma
• B cell malignancy; most occur in immunosuppressed
pts (organ transplantation, AIDS).
• May present as a single mass lesion (immunocompetent
pts) or as multiple mass lesions or meningeal disease
(immunosuppressed pts).
• Dramatic, transient responses occur with
glucocorticoids.
• In immunocompetent pts chemotherapy and RT may
increase survival to18 months; AIDS-related cases
survive about 3 months.
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23. Primary CNS lymphoma
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24. Acoustic neuroma (Schwannoma)
• Usually solitary
• may be part of neurofibromatosis, either solitary
(type I) or bilateral (type II)
• unilateral neurosensory deafness, loss of balance,
facial weakness and loss of sensation, later ataxia
of ipsilateral limbs and gait and raised intracranial
pressure.
• MRI reveals dense, uniformly enhancing tumor at
the cerebellopontine angle.
• Surgical excision may preserve hearing.
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25. Schwannoma
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26. MEDULLOBLASTOMA
• Highly malignant tumors of childhood.
• Age of onset is 4-8.
• Arises from neuroectodermal cells.
• Medulloblastomas occur in the posterior fossa
and frequently disseminate along CSF
pathways.
• begins with vomiting, headaches; later, squint,
ataxic gait, falling, and papilledema.
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27. MEDULLOBLASTOMA
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28. Tumors Metastatic to the Nervous
System
• Most commonly hematogenous.
• Primary tumors that commonly metastasize to
the nervous system are from lung, breast and
malignant melanoma.
• Brain metastases are well demarcated by MRI
and enhance with gadolinium.
• CSF cytology is unnecessary as
intraparenchymal metastases rarely shed cells
into CSF.
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29. • One-third of pts presenting with brain metastasis
have unknown primary (ultimately small cell lung
cancer and melanoma are the most frequent).
• Screening for the primary site includes:
1. Skin and thyroid gland examination.
2. liver function tests
3. CT of chest, abdomen, and pelvis
4. blood carcinoembryonic antigen (CEA)
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30. • Treatment is palliative: glucocorticoids,
anticonvulsants, or RT may improve quality of
life.
• Whole-brain RT is given, because multiple
microscopic tumor deposits are likely
throughout the brain.
• If a single metastasis is found, it may be
surgically excised followed by whole-brain
RT.
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31. Brain metastasis
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32. END
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