Figure 30-1. A. Schematic representation of the astrocytes and endothelial cells of the capillary wall in the normal state (above) and in vasogenic edema (below). Heightened permeability in vasogenic edema is partly the result of a defect in tight endothelial junctions, but mainly a result of active vesicular transport across endothelial cells. B. Cellular (cytotoxic) edema, showing swelling of the endothelial, glial, and neuronal cells at the expense of the extracellular fluid space of the brain. (Reproduced by permission from Fishman.)
Figure 30-2. Glioblastoma. Contrast-enhanced T1-weighted MRI illustrates a large irregularly enhancing tumor with internal necrosis deep within the left cerebral hemisphere.
HistologyAstrocytomaOligoastrocytomaOligodendrogliomaGlioblastomaIDH statusIDH mutantIDH mutantGlioblastoma, IDH mutantGlioblastoma, IDH wild-typeGenetic testing not doneor inconclusiveIDH wild-typeIDH wild-type1p/19q andother geneticparameters1p/19q codeletionOligodendroglioma, IDH mutant and 1p/19q codeletedAfter exclusion of other entities:Diffuse astrocytoma, IDH wild-typeOligodendroglioma, NOS* = characteristic but notrequired for diagnosisDiffuse astrocytoma, NOSOligodendroglioma, NOSOligoastrocytoma, NOSGlioblastoma, NOSDiffuse astrocytoma, IDH mutantATRX loss*TP53 mutation*
Figure 30-3. Simplified molecular genetic analysis of gliomas as a supplement to histological classification. IDH, Isocitrate dehydroxygenase; TP53, tumor (suppressor) protein 53; ATRX, alpha-thalassemia/mental retardation syndrome X-linked. (From Louis DN, Ohgaki H, Wiestler OD, Cavenee WK: World Health Organization Histological Classification of Tumours of the Central Nervous System. France, International Agency for Research on Cancer, 2016. Reproduced with permission from David N. Louis, MD.)
Figure 30-4. Astrocytoma of the left frontal lobe; the T2-weighted MRI shows an infiltrating tumor with minimal mass effect and mild edema. The degree of contrast enhancement is variable but most often less than glioblastoma.
Figure 30-5. Gliomatosis cerebri invading both hemispheres. T2-weighted MRI shows a large confluent area of involvement in the frontal lobes with effacement of overlying cortical sulci. There was slight enhancement along the margins of the lesions after gadolinium infusion. The patient was mentally slow but had no other neurologic signs.
Figure 30-6. A partially cystic oligodendroglioma of the right frontotemporal region. There was no abnormal contrast enhancement.
Figure 30-7. A. Parafalcine meningioma; coronal image, MRI with gadolinium. Note the rightward displacement of an anterior cerebral artery (hypointense flow void) trapped between the right lateral margin of the mass and the right medial frontal lobe. B. Small and asymptomatic left olfactory groove meningioma, MRI with gadolinium.
Figure 30-8. Gadolinium-enhanced MRI of meningioma. Large subfrontal extraaxial mass with central calcification and surrounding vasogenic edema. Homogeneous avid enhancement is characteristic of the tumor.
Figure 30-9. Primary central nervous system lymphoma. Left: Axial T2-FLAIR MRI showing hyperintensity in the right periatrial white matter, without mass effect. Right: Contrast-enhanced MRI reveals two foci of nodular parenchymal enhancement.