ByDR TEFFY JOSE

M1 UNITPROF RUCKMANI’S UNIT

CT scan brain plain study :

An illdefined large hypodense area is seen in the right frontal region & extending across the midline along the genu of the corpus callosum.

There is mild mass effect in the form of subfalcine herniation & squashing of the frontal horn of right lateral ventricle.

Left lateral ventricle is prominent. Midline shift of 4.7mm to left is seen.

Rest of cerebral parenchyma shows normal attenuation. All other areas appear to be normal.

Impression :

Illdefined large hypodense SOL in the right frontal region causing mass effect & midline shift to left.

Suggested CECT / MRI for further evaluation.

MRI scan of brain :

Well defined heterogenously enhancing mass lesion noted in the right frontal region basal aspect crossing over to the left frontal region through the corpus callosum with areas of necrosis & hemorrhage.

The lesion causing mass effect on the frontal horn of both lateral ventricles.The mass lesion measures about 7.8 * 5.6 *4.65 cm.

MR spectroscopy shows increased lactate,choline peak & reuced NAA levels.

All other areas appear to be normal.

Impression :

Features highly s/o GLIOBLASTOMA MULTIFORME

( butterfly glioma ) involving both frontal lobes ( Rt > Lt )

Glioblastoma multiformeA diffusely infiltrating astrocytoma ( WHO

2000 classification Grade IV)

Most common form of cerebral glioma accounting for 12-15 % of all intacranial neoplasms & 50-60% of all astrocytic tumors

Pathogenesis Cell of origin Cell of origin

EGFR ampLOH 10 (PTEN)CDK4 ampMDM2 ampOther LOH (eg DCC)Other amp (eg PDGFR)

DENOVO :GBM WHO grade IV

LOH17p(p53)

Astrocytoma WHO grade II LOH19q LOH9p(INK4a)

Astrocytoma WHO grade III

LOH 10 q(PTEN)

Secondary : GBM, WHO gradeIV

Rapidly growing tumors, highly cellular,often provoke a large amount of edema & usually contain areas of necrosis,& do not have a clearly defined margin.

Supratentorial, frontal lobes are a common site of involvement & extension contralaterally through corpus callosum may give rise to a butterfly pattern.

May become adherent to the overlying dura , but seldom penetrate it.

Infiltration of ependyma & dissemination through CSF pathway may occur in late cases.

Multicentricity can be seen in 4-10% of cases.Extraneural metastasis are rare.

Seen late in adult life, with a peak occurrence b/w 45 – 60 yrs.

May present with SeizureSubacute progression of a focal neurologic

deficitNonfocal neurologic disorder such as

headache,dementia, personality change or gait disorder

Median survival is < 1 yr.

MRI features:

High signal intensity on T2 weighted images & low signal intensity on T1 weighted images

Infiltrate along white matter tracts & deeper lesions have a propensity to extend across the corpus callosum to opposite hemisphere

Often have considerable mass effect, vasogenic edema& more commonly show evidence of haemorrhage

Irregular ring enhancement with nodularity & nonenhancing necrotic foci is typical of glioblastoma

Microscopic fingers of tumour usually extend for variable distances beyond the area of enhancement

Management:

Dexamethasone – administered at the time of diagnosis & continued for the duration of radiotherapy

Accesible astrocytomas are generally resected aggressively, even though total surgical resection is not possible

Post op RT – prolongs survival & improve quality of life ( 5000-7000 cGy to tumor mass in 25-35 fractions, 5days/wk)

Role of stereotaxic radiosurgery & interstitial brachytherapy in glioma trt is uncertain

ChemotherapyIs marginally effective & is used as an

adjuvant therapy following surgery & RTTemozolomide , an oral alkylating agent has

replaced nitrosoureas - 2½ mths longer survival in pts with

methylation & silencing of the promoter for the MGMT gene

Surgical implantation directly into tumor resection cavity of polymer wafers that releases BCNU locally into surrounding brain

Experimental approaches include - Bypassing BBB using local injections into

tumor mass - Intraarterial injection of chemotherapy

following osmotic disruption of BBBMolecular targeted therapies – EGFR

antagonists or inhibitors of its signalling pathways ( Gefitinib /Erlotinib), Bevacizumab

Prognosis: - age, functional status,extent of surgical

resection. - survival ≈ 3 mths (without therapy) , 12 mths

(with therapy). - recurrence is common.