1. Brain Neoplasms: General Considerations
1. Comprise: 10% of all tumors
2. Most common childhood neoplasms
3. Peak incidence at 5th decade
4. Supratentorial tumors in adults
5. Infratentorial tumors in childhood

2. Brain Neoplasms: General Considerations
6. Different tumors in different ages
7. Primary tumors infiltrative, metastatic
well-demarcated
8. Intraneural seeding occur, but no
extraneural metastasis
9. Produce neurologic symptoms by size,
location, invasiveness, and secondary
effects

3. Varieties of brain tumors
Meninges: meningioma, hemangiopericytoma
Astrocytes: astrocytoma (various types)
Oligodendrocytes: oligodendroglioma
Ventricles: ependymoma, choroid plexus papilloma, colloid cyst
Vascular: hemangioblastoma
Primitive cells: germinoma, medulloblastoma, neuroblastoma, pineoblastoma, retinoblastoma
Neuronal: ganglioglioma, gangliocytoma
Pituitary: adenoma, craniopharyngioma
Nerves: schwannoma, neuroblastoma

4. Incidence of Intracranial Gliomas (All ages)
Glioblastomas
Astrocytomas
Ependymomas
Medulloblastomas
Oligodendrogliomas
Choroid plexus papillomas
Colloid cysts
55.0%
20.5%
6.0%
5.0%
2.0%

5. Incidence of Primary Intraspinal Intramedullary Gliomas
63.0%
24.5%
7.5%
3.0%
2.0%
Ependymomas
Astrocytomas (grades 1 and 2)
Glioblastomas
(Astrocytomas grades 3 and 4)
Oligodendrogliomas
Other tumors

6. Frequent brain tumors Meningioma Astrocytoma/glioblastoma
Oligodendroglioma
Ependymoma
Medulloblastoma
Schwannoma/neurofibroma
Phakomatosis

7. Meningioma Arachnoid cells origin Attached to dura, subdural
Common sites
Changes in cranium
Hyperostosis
Invasion
Microscopic: whorls and psammoma bodies

12. Gliomas Astrocytes- astrocytomas Fibrillary Pilocytic
Oligodendrocytes- oligodendrogliomas
Ependyma- ependymomas

13. Astrocytomas Adults: Childhood: Supratentorial Solid Malignant
Infratentorial
Cystic
Benign

14. Adult vs childhood astrocytomas
Adult: fibrillary. Grading varies from low grade malignancy to one of most malignant brain tumor.
Childhood: pilocytic. Very low grade tumor (benign).

15. Fibrillary astrocytomas
Grossly solid
Common in cerebral hemispheres
Low grade in young, higher grade in older
Grading
astrocytoma (low grade)
Anaplastic astocytoma
glioblastoma multiforme

17. Fibrillary astrocytoma: microscopic
Low grade- hypercellularity, pleomorphism
Anaplastic- as above plus mitosis, vascular endothelial proliferation
Glioblastoma multiforme- as above plus necrosis and pseudopalisades. Grossly variegated appearance (multiforme)

21. Pilocytic astrocytoma
Common in childhood
Most slow growing of the gliomas
Sites: cerebellum, around III V., optic nerve
Grossly cystic with mural nodule
Microscopic
elongated hair-like (pilo) elongated cells
Rosenthal fibers

22. Rosenthal fiber definition
Dense, eosinophilic fibers within cytoplasmic processes of astrocytes.
Correspond to aggregate accumulation of intermediate filaments in these processes.

25. Oligodendroglioma Slow growing tumor Potentially malignant
Calcifications

28. Tumors in Ventricles 1. Ependyma: Ependymoma
2. Choroid Plexus: Papilloma

29. Ependymomas
Arise from ependymal lining- ventricles and central canal of spinal cord
Common in childhood
4th V. common in cerebrum
Most common tumor of spinal cord parenchyma in adult
Microscopic
perivascular pseudorosettes
ependymal rosettes

32. Primitive neuroectodermal tumors
Neuroblastoma- cerebral hemispheres
Medulloblastoma- cerebellum
Ependymoblastoma- ventricles
Pineoblastoma- pineal region

33. Medulloblastoma Origin: primitive neuroectodermal cells
Age: 1st decade of life
Site: vermis of cerebellum
May cause hydrocephalus
Subarachnoid dissemination

36. Histologic patterns: definitions
Whorls: onion-skinning pattern of tumor cells
Psammoma bodies: laminated calcium
Pseudopalisading: lining up of the tumor cells around a central necrotic area
Palisade: 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

37. Brain Tumors: Microscopic
Meningioma Whorls and psammoma bodies
Glioblastoma Pseudopalisades
Oligodendroglioma Mosaic/poached-egg
Ependymoma Perivascular pseudorosettes
Medulloblastoma Rosettes

38. Tumors of Nerve Roots and Peripheral Nerves
1. Schwannoma
viii Cranial nerve (Acoustic sch.)
Spinal roots, posterior
Peripheral nerves
2. Neurofibroma
Spinal Roots, rare
3. Malignant variants
Rare

39. Peripheral nerve tumors
Schwannoma
Schwann cells
Compress the nerve trunk
Encapsulated
Easily resectable without nerve damage
Microscopic:
Antony A and B fibers
Verocay bodies
Neurofibroma
Schwann cells, neurites, fibroblasts
Fusiform and involves nerve trunk
Not encapsulated
Not resectable without sacrificing nerve
Micro- 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 capillarity
Discrete, 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

45. Phakomatosis (Neurocutaneous dysplasia)
1. Neurofibromatosis (von Recklinghausen's dis.)
2. Tuberous Sclerosis
3. Sturge-Weber disease (Encephalofacial Angiomatosis)
4. von Hippel-Lindau Disease
5. Neurocutaneous Melanosis

46. Neurofibromatosis 1. Dominant inheritance 2. Multiple neurofibromas
Central - CNS
peripheral nerves
3. Increased incidence of:
meningioma
glioma
schwannoma - bilateral VIII N.
4. Cafe-au-lait (melanosis) in skin
5. Elephantiasis: increased connective tissue

48. Tuberous Sclerosis 1. Dominant inheritance 2. Clinical triad: seizures
mental retardation
adenoma sebaceum
3. Retinal hamartoma (phakoma)
4. Tubers in cerebral cortex
5. Subependymal giant cell astrocytoma
6. Hamartomas in other organs: heart, kidney

51. Venice