Presentation on theme: "Brain Neoplasms: General Considerations"— Presentation transcript:
1 Brain Neoplasms: General Considerations 1. Comprise: 10% of all tumors2. Most common childhood neoplasms3. Peak incidence at 5th decade4. Supratentorial tumors in adults5. Infratentorial tumors in childhood
2 Brain Neoplasms: General Considerations 6. Different tumors in different ages7. Primary tumors infiltrative, metastaticwell-demarcated8. Intraneural seeding occur, but noextraneural metastasis9. Produce neurologic symptoms by size,location, invasiveness, and secondaryeffects
21 Pilocytic astrocytoma Common in childhoodMost slow growing of the gliomasSites: cerebellum, around III V., optic nerveGrossly cystic with mural noduleMicroscopicelongated hair-like (pilo) elongated cellsRosenthal fibers
22 Rosenthal fiber definition Dense, eosinophilic fibers within cytoplasmic processes of astrocytes.Correspond to aggregate accumulation of intermediate filaments in these processes.
29 EpendymomasArise from ependymal lining- ventricles and central canal of spinal cordCommon in childhood4th V. common in cerebrumMost common tumor of spinal cord parenchyma in adultMicroscopicperivascular pseudorosettesependymal rosettes
36 Histologic patterns: definitions Whorls: onion-skinning pattern of tumor cellsPsammoma bodies: laminated calciumPseudopalisading: lining up of the tumor cells around a central necrotic areaPalisade: lining up of tumor cells around their own cytoplasmic processes. No necrosis.Pseudorosette: tumor cells around blood vessels, cells equidistant from vessel walls.Rosettes: tumor cells around central lumen or fibrillary area of cellular processes
39 Peripheral nerve tumors SchwannomaSchwann cellsCompress the nerve trunkEncapsulatedEasily resectable without nerve damageMicroscopic:Antony A and B fibersVerocay bodiesNeurofibromaSchwann cells, neurites, fibroblastsFusiform and involves nerve trunkNot encapsulatedNot resectable without sacrificing nerveMicro- Intermingled cells with wavy nuclei
42 Metastatic brain tumors Most common brain tumor in adults.Common primary sites: melanoma, lung, breast, GI tract, kidney.Most are in cerebrum (MCA territory).In gray-white junctions due to rich capillarityDiscrete, globoid, sharply demarcated tumors. Amenable to surgical resection.Single or multiple.Brain edema frequent.
44 Phakomatosis: definition Phakos (Greek): lentil mole or freckle.Neurologic abnormalities combined with defects of skin or retina, explained by their common ectodermal origin.Involvement of visceral organs