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Differential Diagnosis of Nervous System Disorders

Ventriculomegaly!!navigator!!

  1. MACROCEPHALY
    • increased intraventricular pressure
    1. Obstruction to CSF flow
      1. Communicating hydrocephalus
      2. Noncommunicating hydrocephalus
    2. Overproduction of CSF
      = nonobstructive hydrocephalus
    3. Neoplasm
  2. MICROCEPHALY
    • normal intraventricular pressure
    1. Primary failure of brain growth
      • dysgenesis
        1. Holoprosencephaly
        2. Aneuploidy syndromes (trisomies)
        3. Migrational (<6 layers)
      • environment: alcohol, drugs, toxins
      • infection: TORCH
    2. Loss of brain mantle
      • infection: TORCH
      • vascular accident
        1. Hydranencephaly
        2. Schizencephaly
        3. Porencephaly
      • hemorrhage
        1. Porencephaly
        2. Leukomalacia
        3. NORMOCEPHALY

Colpocephaly!!navigator!!

= dilatation of trigones + occipital horns + posterior temporal horns of lateral ventricles

  1. Agenesis of corpus callosum
  2. Arnold-Chiari malformation
  3. Holoprosencephaly

Enhancing Ventricular Margins!!navigator!!

  1. Subependymal spread of metastatic tumor
    1. Bronchogenic carcinoma (esp. small cell carcinoma)
    2. Melanoma
    3. Breast carcinoma
  2. Subependymal seeding of CNS primary
    1. Glioma
    2. Ependymoma
    3. Giant cell astrocytoma
  3. Ependymal seeding of CNS primary
    1. Medulloblastoma
    2. Germinoma
  4. Primary CNS lymphoma / systemic lymphoma
  5. Inflammatory ventriculitis

Intraventricular Tumor!!navigator!!

Many intraventricular tumors have similar patterns of signal intensity + contrast enhancement.

Lesion location + patient's age, gender, and underlying conditions help narrow the DDx.

Prevalence: 10% of all intracranial neoplasms

  1. Ependymoma 20%
  2. Astrocytoma 18%
  3. Colloid cyst 12%
  4. Meningioma 11%
  5. Choroid plexus neoplasm 7%
  6. Epidermoid / dermoid 6%
  7. Craniopharyngioma 6%
  8. Medulloblastoma 5%
  9. Cysticercosis 5%
  10. Arachnoid cyst 4%
  11. Subependymoma 2%
  12. AVM 2%
  13. Teratoma 1%
  14. Central neurocytoma 0.5%
  15. Metastasis
  16. Central neurocytoma
  17. Oligodendroglioma

Supratentorial Intraventricular Tumors

  1. Lateral ventricle (¾)
    1. Choroid plexus neoplasm (44%)
    2. Giant cell astrocytoma (19%)
    3. Hemangioma in Sturge-Weber syndrome (12%)
  2. Third ventricle (¼)
    1. Astrocytoma (13%)
    2. Choroid plexus neoplasm (6%)
    3. Meningioma (6%)

Uniformly Enhancing Tumor in Trigone of Lateral Ventricle

  1. Choroid plexus neoplasm
  2. Ependymoma
  3. Vascular malformation
  4. Meningioma

Dense Lesion near Foramen of Monro

  1. INTRAVENTRICULAR LESION
    1. Colloid cyst
    2. Meningioma
    3. Choroid plexus neoplasm / granuloma
    4. AVM of septal, thalamostriate, internal cerebral v.
  2. PERIVENTRICULAR MASS
    1. Primary CNS lymphoma
    2. Tuberous sclerosis
      1. subependymal tuber
      2. giant cell astrocytoma
    3. Metastasis from mucin-producing adenocarcinoma / hemorrhagic metastasis (melanoma, choriocarcinoma, hypernephroma, bronchogenic carcinoma, breast carcinoma)
    4. Glioblastoma of septum pellucidum
  3. MASSES PROJECTING SUPERIORLY FROM SKULL BASE
    1. Pituitary adenoma
    2. Craniopharyngioma
    3. Aneurysm
    4. Dolichoectatic basilar artery

Mass in 3rd Ventricle

Purely intraventricular 3rd ventricle masses are rare:

  1. primary choroid plexus lesion: choroid plexus papilloma / carcinoma
  2. vascular malformation of choroid plexus
  3. lesion seeding to choroid plexus:
    • metastatic neoplasm
    • infection (eg, TB)
  1. Colloid cyst
  2. Glioma
  3. Aneurysm
  4. Craniopharyngioma
  5. Ependymoma
  6. Meningioma
  7. Choroid plexus neoplasm
  8. Central neurocytoma

Congenital Malformation of Third Ventricle

  1. Aqueductal stenosis
  2. Persistent embryonic infundibular recess
  3. Cavum veli interpositi cyst
  4. Congenital intraventricular cyst
    Origin: arachnoidal / endodermal / neuroepithelial
    • nonenhancing cyst of CSF density
    • hydrocephalus ← (possibly intermittent) obstruction of aqueduct / foramen of Monro

    DDx: dilatation of 3rd ventricle

Acquired Mass of Third Ventricle

  1. ANTERIOR MASS
    Masses that distort / invade the 3rd ventricle most frequently arise in its anterior aspect and can be broadly grouped into
    1. sellar-suprasellar mass
    2. hypothalamic-chiasmatic mass
  2. POSTERIOR MASS
    1. pineal mass: pineal germinoma, pineal cyst, pineocytoma, pineoblastoma, teratoma
    2. tectal mass
    3. inferior thalamic mass
  3. INFERIOR / FLOOR MASS (uncommon)
    1. Hypothalamic hamartoma
    2. Basilar artery ectasia / aneurysm
    3. Arachnoid cyst
  4. MASS AT FORAMEN OF MONRO
    1. Colloid cyst
    2. Subependymal giant cell tumor (in TS complex)
    3. Subependymoma
  5. INTRAVENTRICULAR MASS

Mass in Anterior Portion of Third Ventricle

  1. pediatric patient
    1. Germinoma
    2. Pilocytic astrocytoma
    3. Craniopharyngioma
    4. Langerhans cell histiocytosis
  2. adult patient
    1. Lymphoma
    2. Pituitary macroadenoma
    3. Craniopharyngioma
    4. Metastasis
    5. Granulomatous disease: eg, sarcoidosis
    6. Sellar meningioma

Mass in 4th Ventricle

  1. Choroid plexus papilloma
  2. Ependymoma / glioma
  3. Hemangioblastoma
  4. Vermian metastasis
  5. AVM
  6. Epidermoid tumor (rare)
  7. Inflammatory mass
  8. Cyst

Outline