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Differential Diagnosis of Nervous System Disorders

Classification of Primary CNS Tumors!!navigator!!

Incidence: 9% of all primary neoplasms (5th most common primary neoplasm); 5–10÷100,000 population per year; account for 1.2% of autopsied deaths

  1. TUMORS OF BRAIN AND MENINGES
    1. Gliomas
      ASTROCYTOMA (50%)
      1. Astrocytoma (astrocytoma grades I–II)
      2. Glioblastoma (astrocytoma grades III–IV)

      OLIGODENDROGLIOMA
      PARAGLIOMA
      1. Ependymoma
      2. Choroid plexus papilloma

      GANGLIOGLIOMA
      MEDULLOBLASTOMA
    2. Pineal tumor
      1. Germinoma
      2. Teratoma
      3. Pineocytoma
      4. Pineoblastoma
    3. Pituitary tumor
      1. Pituitary adenoma
      2. Pituitary carcinoma
    4. Meningioma
    5. Nerve sheath tumor
      1. Schwannoma
      2. Neurofibroma
    6. Miscellaneous
      1. Sarcoma
      2. Lipoma
      3. Hemangioblastoma
  2. TUMORS OF EMBRYONAL REMNANTS
    1. Craniopharyngioma
    2. Colloid cyst
    3. Teratoid tumor
      1. Epidermoid (0.2–1.8%)
      2. Dermoid
      3. Teratoma

CNS Tumors Presenting at Birth!!navigator!!

  1. Hypothalamic astrocytoma
  2. Choroid plexus papilloma / carcinoma
  3. Teratoma
  4. Primitive neuroectodermal tumor
  5. Medulloblastoma
  6. Ependymoma
  7. Craniopharyngioma

CNS Tumors in Pediatric Age Group!!navigator!!

Prevalence:

2.4÷100,000 (<15 years of age); 2nd most common pediatric tumor (after leukemia); 15% of all pediatric neoplasms; 15–20% of all primary brain tumors; M >F

  • increased intracranial pressure
  • increasing head size
  1. SUPRATENTORIAL (50%)
    • Age: first 2–3 years of life
    • Covering of brain: dural sarcoma, schwannoma, meningioma (3%)
    • Cerebral hemisphere: astrocytoma (37%), oligodendroglioma
    • Corpus callosum : astrocytoma
    • 3rd ventricle: colloid cyst, ependymoma
    • Lateral ventricle: ependymoma (5%), choroid plexus papilloma (12%)
    • Optic chiasm: craniopharyngioma (12%), optic nerve glioma (13%), teratoma, pituitary adenoma

      Incidence of Brain Tumors

      All Age GroupsPediatric Age Group
      Glioma34%Astrocytoma50%
      Meningioma17%Medulloblastoma15%
      Metastasis12%Ependymoma10%
      Pituitary adenoma6%Craniopharyngioma6%
      Neurinoma4%Choroid plexus papilloma2%
      Sarcoma3%
      Granuloma3%
      Craniopharyngioma2%
      Hemangioblastoma2%

      Differences of Some Pediatric CNS Tumors

      PNETEpendymomaAstrocytoma
      CThyperisohypo
      T2WIintermed.intermed.increased
      Enhancementmoderateminimalnodule
      Calcification10–15%40–50%<10%
      Cyst formationrarecommontypical
      CSF seeding15–40%rarerare
      Foraminal spreadnoyesno
    • Hypothalamus: glioma (8%), hamartoma
    • Pineal region: germinoma, pinealoma, teratoma (8%)
  2. INFRATENTORIAL (50%)
    • Age: 4–11 years
    • Cerebellum: astrocytoma (31–33%), PNET / medulloblastoma (26–31%)
    • Brainstem: glioma (16–21%)
    • 4th ventricle: ependymoma (6–14%), choroid plexus papilloma

    mnemonic: “BE MACHO”
    • Brainstem glioma
    • Ependymoma
    • Medulloblastoma
    • AVM
    • Cystic astrocytoma
    • Hemangioblastoma
    • Other

Supratentorial Tumor with Mural Nodule

  1. Extraventricular ependymoma
  2. Pleomorphic xanthoastrocytoma
  3. Hemispheric pilocytic astrocytoma
  4. Ganglioglioma
  5. Dysembryoplastic neuroepithelial tumor (DNET)

Supratentorial Midline Tumors

  1. Optic + hypothalamic glioma (39%)
  2. Craniopharyngioma (20%)
  3. Astrocytoma (9%)
  4. Pineoblastoma (9%)
  5. Germinoma (6%)
  6. Lipoma (6%)
  7. Teratoma (3.5%)
  8. Pituitary adenoma (3.5%)
  9. Meningioma (2%)
  10. Choroid plexus papilloma (2%)

Classification by Histology

  1. Astrocytic tumors (33.5%)
  2. “Primitive” neuroectodermal tumor = PNET (21%)
    • Medulloblastoma (16%)
    • Ependymoblastoma (2.5%)
    • PNET of cerebral hemisphere (2.5%)
  3. Mixed gliomas (16%)
  4. Malformative tumors (11.5%)
    • Craniopharyngioma (5.5%)
    • Lipoma (4.5%)
    • Dermoid cyst (1%)
    • Epidermal cyst (0.5%)
  5. Choroid plexus tumors (4%)
  6. Ependymal tumors (4%)
  7. Tumors of meningeal tissues (3.5%)
    • Meningioma (3%)
    • Meningeal sarcoma (0.5%)
  8. Germ cell tumors (2.5%)
    • Germinoma (1.5%)
    • Teratomatous tumor (1%)
  9. Neuronal tumors
    • Gangliocytoma (1.5%)
  10. Tumors of neuroendocrine origin
    • Pituitary adenoma (1%)
  11. Oligodendroglial tumors (0.5%)
  12. Tumors of blood vessel
    • Hemangioma (1%)

Superficial Gliomas!!navigator!!

= peripherally located cortical neoplasms serving as a seizure focus

  1. Ganglioglioma
  2. Desmoplastic infantile ganglioglioma
  3. Gangliocytoma
  4. Dysplastic cerebellar gangliocytoma
  5. Pleomorphic xanthoastrocytoma
  6. Dysembryoplastic neuroepithelial tumor

Multifocal CNS Tumors!!navigator!!

  1. METASTASES FROM PRIMARY CNS TUMOR
    1. via commissural pathways: corpus callosum, internal capsule, massa intermedia
    2. via CSF: ventricles / subarachnoid cisterns
    3. satellite metastases
  2. MULTICENTRIC CNS TUMOR
    1. true multicentric gliomas (4%)
    2. concurrent tumors of different histology (coincidental)
  3. MULTICENTRIC MENINGIOMAS (3%) without neurofibromatosis
  4. MULTICENTRIC PRIMARY CNS LYMPHOMA
  5. PHAKOMATOSES
    1. Generalized neurofibromatosis:
      meningiomatosis, bilateral acoustic neuromas, bilateral optic nerve gliomas, cerebral gliomas, choroid plexus papillomas, multiple spine tumors, AVMs
    2. Tuberous sclerosis:
      subependymal tubers, intraventricular gliomas (giant cell astrocytoma), ependymomas
    3. Von Hippel-Lindau disease:
      retinal angiomatosis, hemangioblastomas, congenital cysts of pancreas + liver, benign renal tumors, cardiac rhabdomyomas

Multifocal Deep Hemispheric Masses

  1. Primary CNS Lymphoma
  2. Gliomatosis cerebri
    • nonenhancing tumor extension (common)

CNS Tumors Metastasizing Outside CNS!!navigator!!

mnemonic: MEGO

  • Medulloblastoma
  • Ependymoma
  • Glioblastoma multiforme
  • Oligodendroglioma

Large Heterogeneous Intracerebral Mass!!navigator!!

  1. High-grade glioma
    • increased relative cerebral blood volume (rCBV) in zone of edema on perfusion-weighted images
  2. Metastasis
    • reduced relative cerebral blood volume (rCBV) in zone of edema on perfusion-weighted images

Mass with Large Tumor Vessels and Edema!!navigator!!

  1. Glioblastoma multiforme
  2. Meningioma

Avascular Mass of Brain!!navigator!!

mnemonic: TEACH

  • Tumor: astrocytoma, metastasis, oligodendroglioma
  • Edema
  • Abscess
  • Cyst, Contusion
  • Hematoma, Herpes

Calcified Intracranial Mass!!navigator!!

  1. Oligodendroglioma (frequent, although rare tumor)
  2. Low-grade astrocytoma (in 10–20%)

mnemonic: Ca2+ COME

  • Craniopharyngioma
  • Astrocytoma, Aneurysm
  • Choroid plexus papilloma
  • Oligodendroglioma
  • Meningioma
  • Ependymoma

Outline