cns neoplasms yr2

NEOPLASMS OF THE

NERVOUS SYSTEM

DR NORAIDAH MASIR

DEPARTMENT OF PATHOLOGY

PPUKM

NEOPLASMS OF THE NERVOUS SYSTEM

Tumours are intracranial or intraspinal

Primary tumours or metastatic tumours

• 50-70% are primary tumours

• CNS tumours accounts for 20% of all

childhood cancers

Primary nervous system tumours

1.Benign

2.Malignant

Based on histological features

Clinical features


Majority are benign - low mitotic count, cellular uniformity,

slow growth.

But benign tumour may infiltrate large area of brain

leading to clinical deficits and poor prognosis.

Difficult to resect completely

May be located in a critical region eg in medulla causing

cardiorespiratory arrest.

Subarachnoid space provides a pathway for

spread into the CSF. Seedings along brain and

spinal cord


LOCATION OF TUMOUR

Majority of childhood tumours arise in posterior

fossa.

Majority of adult tumours within cerebral

hemisphere above tentorium

Important to know the age of patient and

location of tumour for accurate histological

diagnosis


EFFECTS AND COMPLICATION OF TUMOURS

Depends on location of tumor

Effect of space occupying lesion

Raised intracranial pressure

Headache, vomiting, loss of hearing, visual loss,

seizures


EFFECTS AND COMPLICATION OF TUMOURS

1. Compression effect on adjacent neural tissues-

atrophy and loss of function.

2. Destruction of neural tissue due to tumour

infiltration.

3. Cerebral edema. Around tumour due to

neovascularisation with poorly developed BBB.

4. Irritative effects on neural tisues. Abnormal stimulation of nerve – epilepsy, seizures.

5. Hydrocephalus.

6. Increased intracranial pressure


CLASIFICATION OF NERVOUS SYSTEM

NEOPLASMS

BASED ON WHO CLASSIFICATIONS

TUMOUR ARE GRADED ACCORDING TO

BIOLOGIC BEHAVIOUR

GRADE I INDOLENT

GRADE II

GRADE III

AGGRESSIVE GRADE IV


CLASIFICATION OF NERVOUS SYSTEM NEOPLASMS

Based on WHO classifications

1. Gliomas - most common, arise from glial cells

2. Neuronal tumours - contain neuronal and glial elements

3. Poorly differentiated neoplasms - e.g. medulloblastoma

4. Other parenchymal tumours - lymphoma, germ cell

tumours

5. Meningioma - arachnoid meningiothelial cells

6. Metastatic tumours - mostly carcinomas

7. Peripheral nerve sheath tumours - schwannoma,

neurofibromas


Gliomas

Astrocytomas Oligodendroglioma Ependymomas

Pilocytic astrocytoma - grade I

Well differentiated astrocytoma – grade 1

Diffuse astrocytoma - grade II

Anaplastic astrocytoma - grade III

Glioblastoma - grade IV

NEOPLASMS OF THE NERVOUS SYSTEM Astrocytomas

Well differentiated astrocytoma - grade I

Infiltrative slow growing.

Firm, white, ill-defined mass.

Histology: slight increase in cellularity, slightly

abnormal. Neurofibrillary proceeses.

Impossible to completely excise surgically because of

irregular extension.

Progress slowly.

Death 5-10 years after presentation.



Benign behaviour, slow growing

Children and young adults, 25% of intracranium

neoplasm in childhood

Cerebellum, wall of 3rd ventricle etc - location

Treatment – resection. Rarely possible to completely

remove



Nodule of tumour in a cyst. Well circumscribed



Hypercellularity. Uniform fibrillary astrocytes.

Microcystic change. Bipolar cells with long, thin, “hairlike” processes, fibrillary meshworks,

Rosenthal fibres (arrow).


Infiltrative and distort Diffuse astrocytoma - grade II the brain

Bilateral expansion of septum Right frontal tumour, pellucidum by gray glassy expanded, flattened gyri tumour


Infiltrative and distort Diffuse astrocytoma - grade II the brain

Mild to moderate increase in glial cellularity

Variable pleomorphism

GFAP-positive astrocytes

Symptoms depend on location and growth rate

Mean survival up to 5 years


Anaplastic astrocytoma- grade III

Adults

More rapidly growing tumour.

An infiltrative white mass in cerebral hemisphere.

Microscopic: astrocytes, cellular tumour. More pleomorphic.

Neovascularisation. Increased mitotic rate. Higher proliferation rate

Mean length of survival : 15 months. Death after 1-5 years

Treatment : resection and radiation therapy



Microscopic: astrocytes, cellular

tumour. Mitosis. More pleomorphic



Highly aggressive

Poor prognosis

Mean length of survival : 15 months

Treatment : resection and radiation therapy



MRI - irregular large mass

in R parietal lobe Necrotic, haemorrhagic

infiltrating mass



Cellular,

pleomorphic cells,

high mitosis, large

anaplastic cells,

necrosis, vascular

proliferation


Gliomas

Oligodendroglioma

5-15% of gliomas

4th - 5th decade

Grade II

Several years of neurologic complaints

Seizures

Cerebral hemispheres - well

circumscribed gelatinous tumour


Oligodendroglioma - grade II

Tumour cells with round nuclei and clear cytoplasm.

Thin walled capillaries


Gliomas

Ependymomas

Ependyma-lined ventricular system and spinal cord.

Posterior fossa tumour - hydrocephalus dt

obsstruction of 4th ventricle

CSF dissemination occurs - poor prognosis


Ependymomas

Tumour in the 4th Uniform cells with round

ventricle compressing oval nuclei. Form gland-

surrounding structure like structure


Poorly differentiated neoplasms

MEDULLOBLASTOMA

In children

in cerebellum: most common in midline cerebellar vermis.

Derived form primitive neuroectodermal cells.

25% of childhood CNS tumours

Poorly / Undifferentiated tumour

Highly malignant

Poor survival if untreated

Treatment - resection and radiation - improves 5 year survival


MEDULLOBLASTOMA

Grayish fleshy mass

with infiltrative margins

Medulloblastoma destroying superior cerebellum


MEDULLOBLASTOMA

Highly cellular. Cellular sheets of small primitive

or undifferentiated cells. Hyperchromatic nuclei,

mitosis plenty


MENINGIOMAS

Benign adult tumours - slow growing. Uncommon in children

Arise from meningiothelial cells of arachnoid

Attached to dura

Found on external surface of brain and within ventricular

system

Common site: parasaggital part of brain convexity, wing of

sphenoid, sella turcica, foramen magnum

Risk factor; previous radiation therapy

Symptoms- vague and nonlocalising or focal due to

compression of underlying brain


MENINGIOMAS

Parasagital meningioma attached to dura,

compressing underlying brain


MENINGIOMAS

Meningioma with Psammoma bodies in whorled pattern of meningioma cell growth


SCHWANNOMA

Benign tumours from neural-cresst derived Schwann

cells.

Most intracranial tumours at cerebellopontine angle

attached to 8th cranial nerve (acoustic neuroma) -

tinnitus and hearing loss.

Sensory nerve are usually involved - painful lesion


SCHWANNOMA

Bilateral 8th nerve Schwannoma


SCHWANNOMA

Antoni B Verocay bodies

Antoni A

Histology: mixture of 2 growth patterns. Elongated cells

in fascicles with high cellularity (antoni A) and loose

hypocellular areas (antoni B)

Other parenchymal tumours - lymphoma, germ cell tumours

Primary CNS lymphomas

1% of intracranial tumours

Immunossuppresion is a risk factor (eg. AIDS)

Most common type: diffusse large B cell lymphoma

Aggressive

Germ cell tumours of nervous sytem

Along midline

Pineal and supracellar region

< 1% of brain tumours

Teratoma - common congenital germ cell

tumour

Other types - germinoma, yolk sac tumour etc

cns neoplasms yr2

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