Glioblastoma Multiforme

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  • 1. Institute of Basic Medical Sciences IBMS Glioblastoma Multiforme Assignment submitted by: Dr Mohammad Manzoor Mashwani,M.Phil Scholar,Subject: Histopathology Assignment submitted to: Dr Nuzhat Sultana Khattak,Assistant Professor,Histopathology, IBMS, KMU1

2. Table of ContentsIntroduction3Causes3Pathophysiology Pathogenesis 4Clinical features 6Diagnosis 7 Histopathology 8Treatment 9Prognosis 10References122 3. IntroductionGliomas: 1. Astrocytomas Infiltrating& Non-infiltrating 2. Oligodendrogliomas 3. EpendymomasDiffuse astrocytoma (grade II/IV)Anaplastic astrocytoma (grade III/IV)Glioblastoma - GBM (grade IV/IV). (The grade I/IV category is limited to pilocytic astrocytoma.)Glioblastoma Multiforme. It is the most common malignant primary tumor of the brain. It isvery aggressive, involving glial cells. GBM is 20% of all intracranial tumors and 52% of alltissue brain tumors. In North America and Europe incidence is two to three per hundredthousand.GBM incidence is only 23 cases per 100,000 people in Europe and North America. Ofthe 17,000 brain tumors in the USA per year, 60% are gliomas. GBM differ in location withinthe CNS, in age and sex distribution, in growth, in invasiveness, in histological features, inprogression, & in response to therapy.There are 2 variants of GBM: 1. Gliosarcoma 2. Giant Cell Glioblastoma.GBM treatment can be Chemotherapy, radio surgery, radiation, corticosteroids, surgery,antiangiogenic therapy and gene transfer.Prognosis is worst. Median survival time despite of multimodality treatment is fourteen months.CausesThe exact cause is unknown but changes or loss of chromosome 17 & inactivation of p53 has a role.Gender: Men are more affected than women.Most cases are sporadic.Viruses like CMV or SV40 may be the cause.There is some association of GBM with polyvinyl chloride, radiation, malaria and lead exposure.Age: above fifty years.3 4. Ethnicity: Asians, CaucasiansPathophysiology /PathogenesisGBM have necrotizing tissues which are surrounded by anaplastic cells. This along withhyperplastic vessels distinguishes GBM from astrocytomas grade III.Types of GBM: 1. Classical GBM:This type has extra copies of the EGFR gene in 97% of cases. They have higherexpression of EGFR gene. 2. Proneural GBM:This type shows greater alterations in IDHI, TP53, & in PDGFRA. 3. Mesenchymal GBM:Alterations & mutations in Neurofibromatosis type 1(NF1). 4.G BM can be primary or secondary.Primary GBM is sixty percent. These manifest de novo .Secondary GBM is 40% develop in younger patients less than forty five years of age. Malignanttransformation from a low to anaplastic astrocytoma requires one to ten years. There isgenuine evidence which indicates that primary & secondary GBMs are distinct entities.Different genetic pathways involve in GBM.Common genetic abnormalities are: 1. LOH: Loss of heterozygosity on arm 10q is the most common gene change forglioblastomas.This occurs in sixty to ninety percent of cases. This alteration is specificfor GBM associated with poor survival. 2. p53:. The p53 gene deletes or alteres in 25-40% of GBM, more frequently insecondaryGBM.[6] 3. Epidermal growth factor receptor gene: It is involved in the control of cell proliferation. There isover expression as well as rearrangement of receptor. It is more common (40-50%) in primaryGBM. EGFRvIII is a target for kinase inhibitors & peptide vaccines.[11, 12, 13, 14, 15, 16, 17] 4. MDM2: Overexpression or amplification of MDM2 is an alternative mechanism to escape fromp53 -regulated control of cell growth. It binds to p53 and diminishing its activity. 4 5. MDM2 overexpression is the 2nd most frequent (10-15%) gene mutation in GBM. This mutationis associated with a worse prognosis.[7] 5. Platelet-derived growth factoralpha gene: This is a major mitogen for glial cells. It binds toplate-derived growth factor receptor. In secondary GBM it is typically overexpressed. 6. PTEN: It is also called MMAC &TEP1 encodes a TP located at 10q23.3. It is more frequently foundin primary GBM.[14, 18, 19]Rare mutations:MAC1-E1 - AMAGE-E1 - ANRP/B AAdditional alterations in primary GBM :p16INK4A, p16 deletions (30-40%), & retinoblastoma (RB) gene.Genetic alteration in 2ndary GBM:LOH at chromosome arm 19q (50%),RB protein alterations (25%),PTEN mutations (5%).GBM occur most frequently in the subcortical white matter (the cerebral hemispheres). Thecommonly affected sites are the temporal (31%), parietal (24%), frontal (23%), and occipital(16%) lobes.[20] The typical location is frontotemporal. Tumor infiltration commonly extends intothe adjacent cortex /the basal ganglia. Glioblastoma Multiforme grow quickly, producingsymptoms when become sufficiently large.1. Some (< 10%) form slowly. These follow degeneration of low-grade astrocytoma/ anaplastic astrocytoma. These are common in younger patients and are called secondary Glioblastomas and are more common in younger. Mean age forty five versus sixty years.GBM may extend into the meninges or ventricular wall, leading to high protein content inthe CSF. Cancer cells carried in the CSF may spread (rarely) to the spinal cord or causemeningeal gliomatosis. About half of GBMs are bilateral. GBM may take on a variety ofappearances, depending on the amount of hemorrhage, necrosis, or its age. 5 6. Clinical Features: Clinical features largely depend on the location of the tumor than on its pathological characteristics. Following are signs and symptoms found in Glioblastoma multiforme: Headache Personality change Visual lossParalysis or sensory lossIncreased pressure inside skull Headache frontal lobe tumor Vomiting frontal lobe tumorImpaired memory frontal lobe tumorIntellectual disability frontal lobe tumorConvulsions frontal lobe tumorParalysis on one side of bodySeizures parietal and frontal lobe tumorPoor coordination temporal lobe tumorImpaired speechPersonality changes frontal lobe tumorLack of emotion frontal lobe tumorReduced ability to interpret language temporal lobe tumorMotor disturbance temporal lobe tumor6 7. Agraphia parietal lobe tumorParesthesia parietal lobe tumor Loss of positional awareness of body parts parietal lobe tumorSensory changes parietal lobe tumorSpatial disorientation parietal lobe tumorDiagnosisBiopsy is the gold standard.CT, MRI, stereotactic biopsy, craniotomy along with tumor resectionand microscopy are required to confirm the diagnosis. A neurologic examination by the neurologist should be done if there signs and symptoms ofincreased pressure inside the skull that is signs of mental dysfunction, seizures, persistentheadaches vomiting, and swelling of the eye.To determine that whether the tumor is primary or secondary complete examination is necessarythat is MRI, CT scan, and a chest X-ray. Magnetic Resonance Imaging finds low-gradeastrocytomas earlier than computed tomography scan.Following are some specialized tests which may be done depending on the clinical features:Field of vision,7 8. The sharpness of vision &Hearing.Fluid examination may be done in case the above mentioned tests are not conclusive. Fluid thatsurrounds the brain and spinal cord is done.Histopathology:Macroscopy or Gross: Lesions are poorly delineated. The tumor mass consists of necrotictissues. Necrotic tissue is surrounded by hypercellular tissue. Macroscopic appearance of theGBM from region to region is different. Some areas are yellow & soft, some areas are firm andwhite others show areas of cystic degeneration, hemorrhage and necrosis.Microscopy: It is characterized by poorly differentiated, pleomorphic, neoplasticastrocytes. There is marked nuclear atypia & high mitotic activity. Necrosis & vascularor endothelial cell proliferation are important for diagnosis. Necrosis in GBM commonlyoccurs in a serpentine pattern in regions of hypercellularity. Cancer cells gather along the edgesof the necrotic areas, producing a specific pattern known as pseudo-palisading. Vascular cellproliferation is has tufts of piled-up cells. These bulge into the lumen. Double layer is theminimal criterion for this feature. The glomeruloid body can be seen, which is a roundedstructure formed by the tuft due to increased vascular cell proliferation. Vascular endothelialgrowth factor causes this vascular change. Hypoxia makes malignant astrocytes to produceVEGF.A small single biopsy may be deceivable because of different histological features indifferent areas. 8 9. TreatmentTreatment of GBM is difficult due to the following factors: The cancer cells are resistant to conventional therapies The brain is vulnerable to damage due to conventional therapy The brain has a limited capacity to repair itself Many drugs cannot cross the BBB to act on the tumorSymptomatic therapyAnticonvulsants & corticosteroids are used to relieve symptoms and improve neurologicalfunctions of the patient. Palliative therapyIt improves quality of life and achieves a longer survival time. It includeschemotherapy, surgery and radiation therapy. Prognosis is strongly associatedwith gross total resection of tumor.Surgery It is the 1st stage of treatment of GBM. After surgery a reduction of 99% occurs in tumor cells. It is better to remove more than 98% of tumors which has better survival rate. 9 10. Surgery is used for the purpose of biopsy, to remove a large mass pressing against thebrain, to remove disease before secondary resistance to radiotherapy and chemotherapy,and to prolong survival. Recurrence is common despite total resection. RadiotherapyIt is the main treatment after surgery. It increases the median survival time more thandouble. It can reduce the tumor size to 107 cells. The more precise and targeted three-dimensional conformal radiotherapy is sufficient. Radiation dose of 6065 Gy is optimalfor treatment.ChemotherapyTemozolomide sensitize tumor cells to radiation and improves median survival. Avastin (bevacizumab) reduced tumor size in some GBM patients