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Information

Nervous System Disorders

Gangliocytoma!!navigator!!

= rare benign tumor composed of mature ganglion cells

Prevalence: 0.1–0.5% of all brain tumors

Age: children + young adults

Associated with: dysplastic + malformed brain

Cause: ? dysplastic brain

Histo: purely neuronal tumor composed of abnormal mature ganglion cells without neoplastic glial cells (= no immunoreactivity for glial fibrillary acidic protein)

Location: floor of 3rd ventricle >temporal lobe >cerebellum >parietooccipital region >frontal lobe >spinal cord

CT:

  • hyperattenuating mass with little mass effect

MR:

  • iso- to hypointense on T1WI + T2WI
  • bright on proton density images

Dysplastic Cerebellar Gangliocytoma

= LHERMITTE-DUCLOS DISEASE

= rare hamartomatous disorder

Average age: 34 years; occasionally pediatric patients

Associated with: polydactyly, partial gigantism, multiple hemangiomas, leontiasis ossea

Strong association with: Cowden syndrome

Path: disruption of normal cerebellar laminar structure

Histo: dysplastic hypertrophic ganglion cells expanding granule layer; increased myelination of molecular layer of cerebellar cortex; loss of Purkinje cells and white matter; marked reduction in myelination of central white matter of cerebellar folia

  • asymptomatic / symptoms of increased intracranial pressure (headaches, blurred vision, vomiting)
  • slowly progressive cerebellar syndrome (40%)
  • megalencephaly (50%); mental retardation

X-ray:

  • thinning of skull in occipital region

CT:

  • hypo- / isoattenuating cerebellar mass
  • hydrocephalus ← compression of 4th ventricle + effacement of cerebellopontine angle cistern
  • calcification uncommon
  • NO enhancement

MR:

  • cerebellar mass with “striated cerebellum” sign = tiger-striped / corduroy laminated folial pattern of alternating intensity bands on T1WI + T2WI:
    • hyper- and isointense relative to gray matter on T2WI
    • iso- and hypointense relative to gray matter on T1WI
  • enhancement extremely uncommon
  • ± syringohydromyelia

Rx: decompression of ventricles + resection of mass

DDx: medulloblastoma

Ganglioglioma!!navigator!!

= uncommon slow-growing relatively benign tumor composed of glial + nerve cells

Prevalence: 0.4–1.3% of all intracranial neoplasms; 1–4% of all pediatric CNS neoplasms

Peak age: 10–20 years; in 80% <30 years of age; M >F

Histo: containS ganglion + glial elements: ganglion cells (neurons) arise from primitive neuroblasts and mature during growth; usually astrocytic glial cells predominate in various stages of neoplastic differentiation

  • headaches; medically refractory seizures:
    • Most common cause of chronic temporal lobe epilepsy!

Location: frequently above tentorium: in periphery of cerebral hemisphere [temporal (38%) / parietal (30%) / frontal (18%) lobes]; brainstem; cerebellum; pineal region; spinal cord; optic nerve; optic chiasm; ventricles; local involvement of subarachnoid space

  • circumscribed slow-growing mass:
    • solid (43%) / purely cystic (5%) / solid-cystic combination (52%)
  • calcifications (30%)
  • little associated mass effect / vasogenic edema

CT:

  • hypoattenuating (38%) / mixed attenuation (32%) / isoattenuating (15%) / hyperattenuating (15%) mass
  • ± remodeling of skull
  • contrast enhancement (16–80%)
  • Occasionally completely undetectable by CT

MR:

  • variable (hypo- / isointense) nonspecific MR appearance on T1WI
  • commonly at least one hyperintense region on T2WI
  • cystic component may have higher signal intensity than CSF ← gelatinous material
  • nonenhancing / ringlike / homogeneously intense enhancement

Prognosis: favorable; malignant degeneration (6%)

Rx: gross total resection (with resolution of seizure activity in majority of patients)

Desmoplastic Infantile Ganglioglioma

= DESMOPLASTIC INFANTILE ASTROCYTOMA = SUPERFICIAL CEREBRAL ASTROCYTOMA ATTACHED TO DURA

= uncommon variety of ganglioglioma exclusively in infants

Age:<18 months (vast majority); M÷F = 2÷1

Histo: spindle cell neoplasm with oval / elongated moderately pleomorphic nuclei + clusters of larger cells with large prominent eccentric nuclei and cytoplasm containing Nissl bodies

  • rapidly increasing head circumference; seizure (uncommon)

Location: frontal + parietal >temporal >occipital lobes

  • exceptionally large heterogeneously mass:
    • slightly hyperattenuating solid portion typically located along cortical margin
    • cystic components
  • intense enhancement of solid component
  • CHARACTERISTIC extension of enhancement to leptomeningeal margin ← firm dural attachment
  • rare vasogenic edema
  • NO calcification

Prognosis: good

Rx: surgical resection

Outline