THE CENTRAL NERVOUS SYSTEM

Tumors

Gliomas Neuronal tumors Poorly differentiated neoplasms Other parenchymal tumors Meningiomas Paraneoplastic syndromes Peripheral nerve sheath tumors Familial tumor syndromes

Tumors

20% of all childhood cancers are CNS tumors

70% of childhood tumors arise in the posterior fossa

70% of adult tumors arise in cerebral hemispheres, supratentorial

Rarely metastasize outside of the CNSSymptoms – seizures, headaches, focal

neurological deficits, hydrocephalus, ataxia

GliomasAstrocytomasInfiltrating vs non-infiltrating (pilocytic)

Grade I – pilocytic – often cysticGrade II – diffuse astrocytomaGrade III – anaplastic astrocytomaGrade IV – glioblastoma (pseudopalisading)

OligodendrogliomasWhite matterWell-circumscribed, better prognosis

EpendymomasNF2, ependyma-lined ventricular systemPerivascular pseudorosettes

SubepndymomasChoroid plexus papillomas/ carcinomasColloid Cyst of third ventricle

Medulloblastoma

Poorly differentiated

Well-circumscribed

Midline of the cerebellum

Desmoplastic variant

Drop metastases – cauda equina

Meningiomas

Attached to the dura

Usually benign

En plaque

Psammoma bodies

Atypical

Anaplastic

Metastatic

¼ to ½ of intra-cranial tumors in hospitalized patients

Five most commonLungBreastMelanomaKidneyGI

Peripheral Nerve Sheath Tumors

Schwannoma

Neural crest-derived Schwann cell

Acoustic neuroma – actually vestibular

Neurofibroma

Cutaneous

Peripheral nerve – solitary or plexiform

Malignant peripheral sheath tumors

Familial Tumor SyndromesNeurofibromatosis Type I – AD, Lisch nodules, café au lait spots

Neurofibromatosis Type II – AD, 8th nerve schannomas and multiple meningiomas

Tuberous Sclerosis – AD, hamartomas ( cortical tubers) and benign neoplasms of the brain; seizures; liver, kidney, pancreas cysts; angifibromas, shagreen patches, ash-leaf spots, subungal fibromas

Von Hippel – Lindau Disease – AD, hemangioblastomas (cerebellum and retina); cysts of liver, pancreas, kidney; renal cell carcinoma, pheochromocytomas