A brain tumor is a mass or growth of abnormal cells in the brain. It can be primary, originating from brain cells, or secondary/metastatic, spreading from other parts of the body. Primary brain tumors are classified based on their origin and include gliomas, meningiomas, and pituitary adenomas. Common symptoms include headache, vomiting, seizures, and visual/sensory changes depending on the location of the tumor in the brain. Diagnosis involves neurological exams, imaging like CT/MRI, and other tests. Treatment options include surgery, radiation, chemotherapy, and medications to relieve symptoms.
2. BRAIN TUMOR
A brain tumor occupies space within the
skull, growing as a spherical mass or
diffusely infiltrating tissue. The effects
of brain tumors are caused by
inflammation, compression, and
infiltration of tissue.
A variety of physiologic changes result,
causing any or all of the following
pathophysiologic events:
1.Increased intracranial pressure (ICP)
and cerebral edema 2.Seizure activity
and focal neurologic signs
3. Hydrocephalus
4. Altered pituitary function
Neoplastic lesions in the brain
ultimately cause death by increasing
ICP and impairing vital functions, such
as respiration.
3. BRAIN TUMORS ARE CLASSIFIED AS :-
1.Primary Tumor :-
Primary brain tumors originate from cells within the brain. In adults, most
primary brain tumors originate from glial cells (cells that make up the
structure and support system of the brain and spinal cord) and are
supratentorial (located above the covering of the cerebellum). Primary
tumors progress locally and rarely metastasize outside the CNS.
4. CLASSIFICATION OF PRIMARY BRAIN TUMORS ACCORDING TO ORIGIN
:-
I. Intracerebral tumors
A. Gliomas :- infiltrate any portion of the brain ;most common type of brain
tumor
1. Astrocytomas (grades I and II) :- The tumour which arises from astrocytes
(star shaped glial cell).
5. 2. Glioblastoma ( astrocytoma grade III and IV) :- These
are grade 3 and grade 4 astrocytoma.
6. 3.Oligodendroglioma ( low and high grades) :-
This rare tumour arises from cells that make the fatty substance that
covers and protects nerve, usually occurs in the cerebrum.
7. 4. Ependymoma (grade I and IV) :- The tumour that arises from
cells that line the ventricles or the central canal of the spinal cord.
More common in children.
5. Medulloblastoma :- This tumour arises in the cerebellum,
sometimes called as primitive neuroectodermal tumour
8. II. Tumors arisng from supporting structures
A. Meningioma - This tumour arises in the
meninges.
10. C. Schwannoma- A tumour that arises from a
Schwann cell of neuron.
D. Pituitary adenoma- Tumour that arises in the
pituitary gland.
11. E. Pineal region tumour- this rare brain tumour
arises in or near the pineal gland.
F. Germ cell tumour of the brain- this type of
tumour arises from a germ cell.
12. III. Developmental Tumors
a. Angiomas: Masses
composed largely of
abnormal blood vessels, are
found either in or on the
surface of the brain. They
occur in the cerebellum.
14. c. Dermoid tumour: It is a sac like growth that is
present at birth, contains structures such as hair,
fluid, teeth and skin glands that can be found
inside the skull.
d. Epidermoid tumour: This tumours occurs when
the normal developmental cells are trapped
within the growing brain. It has a thin outer layer
of epithelial cells surrounding fluid, keratin and
cholesterol.
IV. Metastaic lesions
15. 2.Secondary Tumor :- Secondary, or metastatic,
brain tumors develop from structures outside the
brain and are twice as common as primary brain
tumors. Metastatic lesions to the brain can occur
from the lung, breast, lower gastrointestinal tract,
pancreas, kidney, and skin (melanomas)
neoplasms.
17. LOCALISED SYMPTOMS :-
Many tumors can be localized by correlating the signs and
symptoms to specific areas in the brain , as follows :
1. A frontal lobe tumor may also produce changes in
emotional state and behaviour as well as an apathetic
mental attitude. The patient often becomes impulsive,
inappropriate in speech, gestures and behavior.
2. A parietal lobe tumor may cause deacreased sensation on
the opposite side of the bady Or genralized seizures.
18. 3.A temporal lobe tumor may cause seizures as well as psychological
disorders.
4.An occipital lobe tumors produces visual manifestation: contralateral
homonymous hemianopsia ( visual loss in half of the visual field on
the opposite side of the tumor) and visual hallicinations.
5.A cerebellar tumor causes dizziness, an ataxic Or staggering gait with
a tendency to fall toward the side of the lesion; marked muscle
incoordination and nystagmus, usually in the horizontal direction.
19. 6. A cerebellopontine angle tumor - Tinnitus and
Vertigo, Nerve deafness, Numbness and tingling
of the face and tongue.
Brainstem tumors may be associated with cranial
nerve deficits along with complex motor and
sensory function impairments.