Adult primary brain tumor Notes


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Adult brain tumors

NOTES NOTES ADULT PRIMARY BRAIN TUMORS GENERALLY, WHAT ARE THEY? PATHOLOGY & CAUSES ▪ Diverse central nervous system cell neoplasms ▫ Benign/malignant RISK FACTORS ▪ Genetic predisposition ▪ Ionizing radiation exposure ▪ Dietary N-nitroso compounds (NOCs) COMPLICATIONS ▪ Mass effect: hydrocephalus, ↑ intracranial pressure, herniation ▪ Neurocognition, motor dysfunction, death SIGNS & SYMPTOMS ▪ Vary depending on tumor type ▪ May be asymptomatic; headache; visual, hearing deficits; nausea; vomiting; altered level of consciousness (LOC) DIAGNOSIS DIAGNOSTIC IMAGING CT scan/MRI ▪ Visualizes tumor mass 464 OSMOSIS.ORG LAB RESULTS ▪ Biopsy: histopathologic, molecular examination OTHER DIAGNOSTICS ▪ Tumor grades: World Health Organization (WHO) grading system TREATMENT ▪ Dependent on tumor stage, grade MEDICATIONS ▪ Steroids ▪ Monoclonal antibodies ▫ Avastin ▪ Chemotherapy SURGERY ▪ Resection OTHER INTERVENTIONS ▪ Radiation
Chapter 61 Adult Primary Brain Tumors GLIOBLASTOMA MULTIFORME (GBM) PATHOLOGY & CAUSES ▪ Highly malignant, aggressive glial cell tumor ▪ Location: usually hemispheric white matter ▫ Mass with grayish periphery, necrosed yellow center, multiple bleeding zones ▪ World Health Organization (WHO) grade IV tumor TYPES Histology ▪ Giant-cell glioblastoma ▫ Multinuclear, giant cells ▪ Gliosarcoma ▫ Combined astrocytic, sarcoma-like components; squamous/gland-like structures → possible differentiation into other tissue ▪ Epithelioid glioblastoma ▫ Eosinophilic cytoplasm in large epithelioid cells Development-based ▪ Correlated with Isocitrate dehydrogenase (IDH) gene mutation ▪ Primary ▫ Spontaneous development, individuals aged > 50 ▫ AKA IDH wild-type: no IDH gene mutation ▪ Secondary ▫ Individuals aged < 50 ▫ Low-grade astrocytoma (WHO grade II) ▫ Anaplastic astrocytoma (WHO grade III) Subtypes: molecular characteristics ▪ Classic ▫ Molecular changes resemble primary type ▪ Proneural ▫ Secondary type gene mutations ▪ Neural ▪ ↑ expression of NEFL, GABRA1, SYT1, SLC12A5 tumor markers ▪ Mesenchymal ▫ ↓ NF1 gene, ↑ TNF and NF-κB pathway genes expression CAUSES ▪ Genetic alterations Primary GBM ▪ Epidermal growth factor receptor (EGFR) gene mutation → overexpression, constant receptor activation → uncontrolled cell proliferation ▪ Heterozygosity loss commonly affects long arm of chromosome 10 ▪ Phosphatase, tensin homologue (PTEN) gene mutation → tyrosine phosphatase activity loss → overactivated signaling pathways → ↑ proliferation Secondary GBM ▪ IDH1/IDH2 gene mutation → 2-hydroxyglutarate (2-HG) overproduction → impaired DNA methylation due to 2-HG ▪ TP53 mutation → tumor suppression function lost ▪ Heterozygosity loss on long arm of chromosomes 13, 19, 22 ▪ Platelet-derived growth factor (PDGF) gene mutation with overexpression → ↑ PDGF receptor binding → ↑ proliferation RISK FACTORS ▪ White, biologically-male individuals of Jewish descent, aged 45–70 ▪ Genetically-inherited diseases ▫ Li–Fraumeni syndrome, tuberous sclerosis, neurofibromatosis OSMOSIS.ORG 465
▪ ▪ ▪ ▪ Radiation exposure Tobacco use Pesticide exposure Viruses ▫ Simian virus 40, Human herpesvirus 6, Cytomegalovirus COMPLICATIONS ▪ Extension to ventricular wall ▪ Meningeal gliomatosis ▫ Malignant cell spread to spinal cord via cerebrospinal fluid (CSF) ▪ Recurrence ▪ Multifocality ▪ Mass effect ▫ Obstructive hydrocephalus, ↑ intracranial pressure, herniation ▪ Seizures ▫ Supratentorial glioblastoma OTHER DIAGNOSTICS Histology ▪ Inadequate astrocyte differentiation with atypical nuclei, uncontrolled cell proliferation with shape/size cell variation ▪ Immunostaining ▫ Commonly positive glial fibrillary acidic protein (GFAP) SIGNS & SYMPTOMS ▪ Severe morning headache, attenuates throughout day → focal symptomatology ▫ Motor (gradual), sensory, vision loss; aphasia ▪ Mental changes ▫ Altered mood, personality; impaired comprehension, concentration, memory Figure 61.1 An MRI scan of the head in the coronal plane demonstrating glioblastoma of the left temporal lobe. DIAGNOSIS DIAGNOSTIC IMAGING CT scan ▪ Hypodense central area, irregular ring-like edge enhancements MRI ▪ T1: hypointense center ▪ T2: hyperintense center, peripheral lowattenuated vasogenic edema Magnetic resonance spectroscopy (MRS) ▪ ↑ choline, lactate, lipid peaks ▪ ↓ N-acetylaspartate, myo-inositol peaks Positron emission tomography (PET) ▪ ↑ glucose metabolism 466 OSMOSIS.ORG Figure 61.2 The histological appearance of a glioblastoma multiforme. The tumor is composed of malignant glial cells with marked nuclear pleomorphism. The tumor demonstrates necrosis and is forming microvascular channels.
Chapter 61 Adult Primary Brain Tumors TREATMENT MEDICATIONS ▪ Avastin (common) SURGERY ▪ Total/subtotal tumor resection OTHER INTERVENTIONS ▪ Adjuvant chemotherapy, radiation therapy HEMANGIOBLASTOMA PATHOLOGY & CAUSES ▪ Benign tumor; vascular cell proliferation, new blood vessel formation ▪ Cherry red cystic/solid mass structure in cerebellum, spinal cord, brainstem ▪ WHO grade I tumor CAUSES Sporadic ▪ Usually solitaire, cerebellum most commonly affected Von Hippel–Lindau (VHL) disease ▪ Gene impairment with HL protein dysfunction → hypoxia inducing factor (HIF) build up → ↑ production of angiogenic factors, vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), transforming growth factor (TGF) → stimulation of angiogenesis ▪ Small, multiple lesions ▪ Common spinal cord affection, retinal hemangiomas also occurs COMPLICATIONS ▪ Acute hemorrhage ▫ Intracerebral: brainstem compression/ tonsillar herniation, obstructive hydrocephalus ▫ Spinal: acute quadriplegia ▪ Tumor mass effect → ↑ intracranial pressure ▪ Local structure compression: neurologic deficits (e.g. oculomotor nerve dysfunction, motor weakness, sensory deficits) ▪ Paraneoplastic erythrocytosis → polycythemia SIGNS & SYMPTOMS ▪ Tumor location-dependent ▫ Brainstem: visual, sensory impairment; motor weakness ▫ Cerebellum: ataxia ▫ Spinal cord: pain, sensory impairment ▪ In von Hippel–Lindau disease (VHL) ▫ Effect on retina → vision loss RISK FACTORS ▪ Biologically-male individuals, aged 20–50 OSMOSIS.ORG 467
DIAGNOSIS DIAGNOSTIC IMAGING MRI ▪ T1 hypointense/T2 hyperintense mass with defined edges CT scan ▪ Hypodense mass Ultrasound ▪ Hyperechoic zones amid surrounding tissue Angiography ▪ Preoperative tumor visualization Figure 61.4 The histological appearance of a hemangioblastoma. The tumor is composed of numerous, closely-packed, thin-walled capillaries with underlying neoplastic stromal cells. OTHER DIAGNOSTICS Histology ▪ Two components ▫ Endothelial: small endothelial cells with sparse cytoplasm ▫ Stromal: cells with eosinophilic cytoplasm, numerous vacuoles TREATMENT MEDICATIONS ▪ Antiangiogenic treatment ▫ ↓ EDGF production SURGERY ▪ Excision ▪ Stereotactic radiosurgery Figure 61.3 Immunohistochemical staining of a hemangioblastoma with CD31 highlights the endothelial component of the tumor (dark brown). 468 OSMOSIS.ORG
Chapter 61 Adult Primary Brain Tumors MENINGIOMA PATHOLOGY & CAUSES ▪ Tumor arising from dome-shaped meningeal arachnoid cells with base on meninges ▪ Intracranial (usual), spinal (occasional) ▪ WHO grade I, II, III (morphologydependent) CAUSES COMPLICATIONS ▪ Recurrent meningiomas ▪ Mass effect ▫ Obstructive hydrocephalus, ↑ intracranial pressure, herniation ▪ Bone abnormalities ▫ Reactive sclerosis, bone invasion/erosion possible (meningioma located on skull base) ▪ Seizures Sporadic ▪ TNF-receptor associated factor 7 (TRAF7) mutation Genetic predisposition ▪ Long arm of chromosome 22 loss → NF2 tumor suppressor gene impairment ▪ SMARCB1 tumor suppressor gene mutation ▪ MEN1 tumor suppressor gene mutation RISK FACTORS Genetically-inherited diseases ▪ Neurofibromatosis type 2 ▫ Intracranial localization (usual), spinal meninges (occasional) ▫ Associated with multiple meningiomas ▪ Schwannomatosis ▪ Multiple endocrine neoplasia type I (MEN I) Ionizing radiation ▪ Radiation exposure, dental radiographs, diagnostic CT scan (children) Other risk factors ▪ Obesity ▪ Black, biologically-female individuals of African descent more prone, ↑ incidence in later age Figure 61.5 An MRI scan of the head in the coronal plane demonstrating a meningioma. SIGNS & SYMPTOMS ▪ May be asymptomatic; very slow growth ▪ Symptoms tumor location-dependent Visual impairment ▪ Sella turcica vicinity ▫ One-sided papilledema, optic atrophy of other eye (Foster–Kennedy syndrome) ▪ Cavernous sinus meningiomas ▫ Compression of cranial nerves supplying extraocular muscles → muscles OSMOSIS.ORG 469
weakness, double vision ▪ Optic nerve meningiomas ▫ Gradual, monocular, vision loss DIAGNOSTIC IMAGING Impaired hearing and smell ▪ Cerebellopontine angle meningiomas ▫ Sensorineural deafness ▪ Olfactory groove meningiomas: anosmia MRI ▪ T1 hypointense/T2 hyperintense duralbased mass, dural thickening with tail-like structure (“tail sign”) Behavioral changes ▪ Apathy, impaired attention, impulsivity ▪ Usually subfrontal meningiomas CT scan ▪ Isodense mass, brain tissue compression Muscle weakness ▪ Parasagittal meningiomas ▫ Contralateral leg weakness ▪ Foramen magnum meningiomas ▫ Lesion-side arm weakness → ipsilateral leg progression → contralateral leg affection → contralateral arm weakness ▪ Spinal cord meningiomas ▫ One-sided plegia of extremities, sensory loss on other side (Brown–Séquard syndrome) DIAGNOSIS PET ▪ ↑ uptake of 18F-Fluorodeoxyglucose OTHER DIAGNOSTICS Histology ▪ WHO Grade I ▫ Benign, not classified ▪ WHO grade II ▫ Atypical, needs to have at least three of ↑ nucleus-cytoplasm ratio, ↑ cellularity, prominent nucleus, unorganized growth, focal necrosis ▪ WHO grade III ▫ Malignant; ↑ mitotic index with atypical cells, brain tissue infiltration, multifocal necrosis TREATMENT ▪ Monitoring ▫ Lesions small, asymptomatic Figure 61.6 The histological appearance of a meningioma showing a typical whorled architecture. SURGERY ▪ Resection ▫ Large symptomatic/asymptomatic tumors ▪ Stereotactic radiosurgery ▫ Hard-to-reach/smaller than 3cm/1.18in lesions OTHER INTERVENTIONS ▪ Radiotherapy ▫ Primary management/adjuvant therapy 470 OSMOSIS.ORG
Chapter 61 Adult Primary Brain Tumors OLIGODENDROGLIOMA PATHOLOGY & CAUSES SIGNS & SYMPTOMS ▪ A tumor derived from oligodendrocytes ▪ Supratentorial in frontal/temporal white matter (usual); spinal cord (occasional) ▪ Genetic alteration combination → oligodendroglioma grade II development → oligodendroglioma grade III progression ▪ Oligodendroglioma grade III can develop without oligodendroglioma grade II ▪ May be asymptomatic; slow tumor growth ▪ Seizures ▫ Focal/secondarily generalized ▪ Focal symptomatology ▫ Frontal lobe: one-sided muscle weakness, impaired sensory perception, impaired memory ▫ Temporal lobe: impaired language TYPES WHO classification ▪ Grade II ▫ Low-grade, low mitotic index with atypical nuclei ▪ Grade III ▫ High-grade (anaplastic), ↑ cellular density, ↑ mitotic index with atypical nuclei, microvascular proliferation ▪ Oligodendroglioma not-other-specified (NOS) ▫ Tumors with appropriate histologic characteristics without 19p-1q chromosomes co-deletion or IDH1/IDH2 gene mutation CAUSES ▪ IDH1/IDH2 gene mutation ▪ 19p-1q chromosomes co-deletion due to unbalanced translocation RISK FACTORS ▪ Biologically-female > biologically-male individuals, aged 25–45, most commonly affected DIAGNOSIS DIAGNOSTIC IMAGING MRI ▪ T1 hypointense/T2 hyperintense mass CT scan ▪ Hypodense, delineated tumor mass with calcification present LAB RESULTS ▪ Genetic testing ▫ IDH gene mutation, 19p-1q detection OTHER DIAGNOSTICS Histology ▪ Needed for diagnosis ▫ Diffuse infiltrative tumors ▫ Large nuclei with perinuclear halo— “fried egg” appearance ▫ ↑ capillary branching—“chicken wire” appearance OSMOSIS.ORG 471
TREATMENT MEDICATIONS ▪ Chemotherapy SURGERY ▪ Resection OTHER INTERVENTIONS Figure 61.7 The histological appearance of an oligodendroglioma. The tumor is composed of monomorphic malignant glial cells with perinuclear halos and visible nucleoli. 472 OSMOSIS.ORG ▪ Radiation therapy

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