Brain Tumors

GLIAL CELLS…….NEURONS

GLIAL CELLS

WHAT IS A BRAIN TUMOR?

PRIMARY VS. SECONDARY:

May lodge into the ff structures: - Brain parenchyma – most common area of metastases - Leptomeninges – pia mater & arachnoid - Dural space

LOCALIZED VS. INVASIVE

THEY CAN ALSO BE:

WHO GRADING SYSTEM

WHO HISTOLOGIC CLASSIFICATION OF TUMORS OF THE CNS

1. Tumors of Neuroepithelial Tissue

2. Tumors of Cranial and Spinal Nerves

3. Tumors of the Meninges

4. Tumors of Uncertain Histogenesis1. Hemangioblastoma from primitive vascular structures

5. Lymphomas and Hematopoietic Neoplasm

6. Germ Cell Tumor1. Ex: Germinoma – common in pineal gland area

7. Cysts and Tumor-like lesions1. Usually in the third ventricle

8. Tumors of the Sellar Regions

9. Local Extension from Regional Tumors

10. Metastatic Tumors

WHAT CAUSES A BRAIN TUMOR?

 

OCCUPATIONAL EXPOSURES

COMMON TYPES OF BRAIN TUMORS

Astrocytomas come in four major subtypes: juvenile pilocytic astrocytoma (grade 1) fibrillary astrocytoma (grade 2) anaplastic astrocytoma (grade 3) glioblastoma multiforme (grade 4)

The higher the grade, the more aggressive the tumor.

AGE INCIDENCE

Adults - Supratentorial: 80-85% - Intratentorial: 15-20%

- Children - Intratentorial: 60% - Supratentorial: 40%

CLINICAL PRESENTATION

Slowly Progressive

Tumors

CEREBRAL DYSFUNCTION

CEREBELLAR DYSFUNCTION

INCREASED ICP

PAPILLEDEMA

COURSE OF ILLNESS

ANCILLARY PROCEDURES

TREATMENT OF BRAIN TUMORS

THE NEUROLOGICAL REHABILITATION TEAM:

The Rehabilitation Team

The Rehabilitation Team

COMMON TYPES OF BRAIN TUMORS

I. GLIOMAS - Most common primary brain tumor - 50% of all symptomatic brain tumors - Incidence increases with advancing age - Peak in 8th and 9th decades - No known environmental factors - No behavioral lifestyle choices - Ionizing radiation: the only clear risk factor - Originate from glial cells or their stem cell

precursors

GLIOMAS Include:

a. Astrocytoma b. Oligodendroglioma c. Ependymoma

- WHO Classification Basis a. Increased cellularity b. Nuclear atypia c. Endothelial proliferation d. Necrosis

A. ASTROCYTOMA - Most common glioma - Cerebral astrocytoma (more in adults)

- Behavioral changes - Seizures - Hemiparesis - Language difficulty

- Cerebellar astrocytoma (more in children) - Hemisphere - Ataxia

- Brain stem (children) - Pons - CN deficits

GRADE I: Pilocytic Astrocytomas

Primary in children & young adults

Focal astrocytoma may be associated with: Neurofibromatosis type I

(NF-I) Unusually excellent

prognosis

GRADE II: Diffuse or Fibrillary

Astrocytoma Most common in the cerebral

hemisphere in young adults Low grade or benign

histologically Infiltrative – usually a problem

because the tumor cannot be resected completely if this is a characteristic of the tumor

Complete resection not possible

Latent potential for malignant transformation

GRADE III: ANAPLASTIC ASTROCYTOMAGRADE IV: GLIOBLASTOMA MULTIFORME

Grades III and IV are high-grade gliomas 20% of all intracranial tumors 55% of gliomas 80% of gliomas of the cerebral

hemispheres in adults Peak incidence middle to late adulthood Males/females = 1.61 No familial predilection

ANAPLASTIC ASTROCYTOMA Have increased pleomorphism, enlarged

nuclei and most importantly, increased proliferative activity that is reflected as increased mitotic activity.

There should be NO necrosis or endothelial proliferation.

Presence of either/both is suggestive of worse biological behavior.

GLIOBLASTOMA MULTIFORME CSF seeding:

Malignant cells in the CSF may form: a. Distant foci in spinal roots b. White spread meningeal gliomatosis

CSF seeding implies that GBM can go to the CSF spaces such as the subarachnoid space & communicate with the ventricular system

Extraneural metastasis - To bone & lymph nodes (very rare) after a craniotomy

Pseudopalisading around the necrosis is common in GBM

Can cross the midline in a “butterfly” pattern: this shows the aggressive nature of this tumor because the midline is composed of a tough dura

GLIOBLASTOMA MULTIFORME

IMAGING: HIGH- AND LOW-GRADE GLIOMAS High-grade or malignant gliomas: appear as

contrast enhancing mass lesions which arise in white matter & are surrounded by edema

Low-grade gliomas: typically non-enhancing lesions that diffusely infiltrate brain tissue & may involve a large region of brain

Low-grade gliomas are usually best appreciated on T2- weighted MRI scans.

PROGNOSIS OF ASTROCYTOMAS Median survival

GBM: 1 year Anaplastic astrocytoma: 3 years Low-grade astrocytoma: 5 years Others survive a decade or more Most die from transformation of tumor to higher

grade

B. OLIGODENDROGLIOMA Derived from oligodendrocytes or their precursors

Oligodendrocytes produce the white matter in the brain

5-7% of all intracranial gliomas Most often in the 3rd and 4th decades Males:females = 2:1 Found primarily in cerebral hemispheres, within

the brain parenchyma Highly infiltrative May metastasize distantly in ventricular &

subarachnoid spaces like the GBM (CSF seeding) Round regular “fried-egg” cells

OLIGODENDROGLIOMA

“FRIED EGG CELLS OF OLIGODENDROGLIOMA”

PROGNOSIS OF OLIGODENDROGLIOMA Median Survival

Low-grade oligodendrogliomas: 8-16 years Anaplastic oligodendrogliomas: 5 years Tumors that have 1p/19q LOH—best prognosis Many pxs die from malignant transformation of

the tumor

C. EPENDYMOMA Arise from ependymal cells (an

intraventricular tumor) More common in children

10% pediatric intracranial tumors 5% of adult intracranial tumors

Most common in the 4th ventricle Ataxia, vertigo, increased ICP

May grow in brain parenchyma without obvious attachment to the ventricular system

Spinal lesions more common in adults Intracranial ependymomas predominate in

children

EPENDYMOMA

HISTOLOGICAL CHARACTERISTICS OF EPENDYMOMA

PROGNOSIS 5-year survival: 40-50% 10-year survival: 47-68% Better prognosis:

Young age Infratentorial Gross total excision Low-grade histology

II. MENINGIOMA Second most common primary brain tumor Originate from arachnoid cells

(meningoepithelial cap cells normally seen in arachnoid villi)

20% of all intracranial tumors (with asymptomatic cases—40% or more)

7% of all posterior fossa tumors 3-12% of cerebellopontine angle tumors

MENINGIOMA

II. MENINGIOMA Most diagnosed in 6th % 7th decades Female: Male—3:2 to 2:1 Multiple in 5-15% (NF-2) 90% intracranial 10% intraspinal Spinal meningioma: 10x in women All familial meningiomas occur with NF-2 Rare in children (more in boys)

- Rare with dural attachments - Usually Intraventricular or posterior fossa - Commonly with sarcomatous changes - Frequently with NF-2

ETIOLOGY OF MENINGIOMA

PROGESTERONE RECEPTORS - Expressed in 80% of women with meningiomas - Expressed in 40% of men with meningiomas

PATHOLOGY Nodular tumors occasionally meningiomas en

plaque (sheer-like formation) Highly vascular Encapsulated and attached in the dura

(blood supply from external carotid artery) Hyperostosis of adjacent bone (bone

proliferation)

HISTOLOGICAL CHARACTERISTICS Benign Typical features:

- Whorls of arachnoid cells surrounding a central hyaline material that eventually calcifies to form PSAMMOMA BODIES

- No characteristic cytologic marker

CLINICAL MANIFESTATIONS Some are asymptomatic—found incidentally by MRI But may have symptoms:

Tumor location: by compression of underlying neural structures

Sites of predilection - Cerebral convexity (Sylvian & parasagittal areas) - Falx cerebri - Skull base

- Olfactory groove - Sphenoid ridge - CP angle - Tuberculum sella

DIAGNOSIS

DIAGNOSIS Cranial CT Scan

Isointense or slightly hyperintense Hyperostosis—20% Isointense (65%) or hypointense (35%) in T1 and

T2 Gadolinium

Angiography Hypervascular mass

embolization reduce the risk of intraoperative bleeding MR Angiography & Venography

GROWTH RATE OF MENINGIOMA Less than 1 cm per year (very slow growth

but can recur) Tumor doubling time: 1.27 to 14.35 years

SURGERY Complete excision may cure many

meningiomas The extent of resection is the most important

in determining recurrence For recurrence: reresection

RADIATION THERAPY Residual tumor after surgery Recurrent tumor Atypical or malignant histology

III. TUMORS OF THE PITUITARY GLAND Third most common primary brain tumor Often asymptomatic Incidence at autopsy:

1.7 – 24% Most common in adults in

the 3rd and 4th decade 10% incidence in children & adolescents Not hereditary except MEN-1 (multiple

endocrine neoplasia)

PATHOLOGY Microadenoma

- Less than 1cm - Symptoms due to excess hormone secretion (or

hyperfunctioning) a. Growth hormone b. Gonadotropin c. Thyroid hormone d. Adrenal hormone e. Prolactin hormone

Macroadenoma - More than 1cm - Symptoms due to compressing normal pituitary

gland and neural structure causing hypofunctioning

PATHOLOGY Endocrine Active (Secretory)

- Prolactinoma - Most common secretory intrasellar endocrine active

tumor - Secreted either by microadenoma or macroadenoma

- Growth hormone - Before closure of epiphysis gigantism - After closure of epiphysis acromegaly

- ACTH: Cushing’s Syndrome - FSH and LH

- Endocrine Inactive (Non-secretory or null cell adenoma)

- 10% mixed secretory tumor

HISTOLOGICAL CHARACTERISTICS: Almost all are histologically benign Pituitary CA: rare Macroadenomas Pituitary Carcinoma

MACROADENOMAS May invade dural bone May infiltrate surrounding structure Locally invasive pituitary adenomas are

nearly always histologically benign Pleomorphism and mitotic figure insufficient

for diagnosis of carcinoma (may be seen in benign adenomas)

Invasive character independent of growth rate

PITUITARY CARCINOMAHighly invasiveRapidly growing & anaplasticUnequivocal diagnosis relies on

presence of distant metastasis

CLINICAL MANIFESTATIONS OF TUMORS OF THE PITUITARY GLAND Compression of neural and vascular structures

Headache Hypopituitarism Visual symptoms

- visual loss - visual field abnormality: bitemporal hemianopsia is the

most common Papilledema is rare May enlarge with pregnancy 5% of pituitary adenoma present with pituitary

apoplexy

CLINICAL MANIFESTATIONS OF TUMORS OF THE PITUITARY GLAND Optic chiasm

- Between hypothalamus & sella turcica - When this is compressed bitemporal hemianopsia

Optic nerve - When this is compressed ipsilateral blindness

Optic tract - When this is compressed contralateral homonymous

hemianopsia Diaphragma sella

- The dura that covers sella turcica As tumor grows forward to the sella compress the basal

dura headache affected pain-sensitive intracranial structures

- Basal dura is a pain-sensitive intracranial structure

VISUAL FIELD PATHWAYS

BITEMPORAL HEMIANOPSIA

IPSILATERAL BLINDNESS

CONTRALATERAL HOMONYMOUS HEMIANOPSIA

HYPOTHALAMUS + THALAMUS - Form the lateral wall of the 3rd ventricle - Any pathology in the ventricular system will

cause accumulation of CSF proximal to the block hydrocephalus

SUPRASELLAR REGION – REGION OF THE HYPOTHALAMUS An example of a suprasellar tumor is a craniopharyngoma

in children & adults A craniopharyngoma can compress the third ventricle &

cause the ff: (hydrocephalus with signs of increased ICP) - Headache - Vomiting - Papilledema

Nowadays, pituitary adenoma usually does not grow until the region of the hypothalamus because visual problems prompt consult & diagnosis.

Papilledema is also rare because it manifests late in the course of the tumor. Before that happens, patient must have been diagnosed already

Obstructive hydrocephalus: rare because of diagnosis at visual problem level

PITUITARY APOPLEXY - Hemorrhage or infarction of pituitary

adenoma - Sudden onset of headache, nausea,

vomiting, visual loss, diplopia, altered mental status

- Diagnosis by CT or MRI - Treatment emergency surgery

DIAGNOSIS - X-ray – will show you ballooning of the sella

turcica - Cranial MRI

- Best way to evaluate pituitary pathology

TREATMENT

VIDEO ON ENDOSCOPIC TRANSSPHENOIDAL SURGERY