Brain Tumor In Child > 1 Year

Susan I. Blaser, MD, FRCPC

DIFFERENTIAL DIAGNOSIS

Common

Pilocytic Astrocytoma
- Cerebellar JPA
- Optic Pathway Glioma
- Pilomyxoid Astrocytoma (Rare)
Medulloblastoma (PNET-MB)
Ependymoma
Pediatric Brainstem Glioma
Low-Grade Diffuse Astrocytoma
Subependymal Giant Cell Astrocytoma
DNET
Craniopharyngioma

Less Common

Rare but Important

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Diffusion weighted imaging helpful
All of the following restrict on DWI
- PNET-MB
- Pineoblastoma (pineal PNET)
- Atypical teratoid-rhabdoid tumor (ATRT)
- Germinoma
- Epidermoid
May present with hemorrhage into tumor
- Primary CNS sarcoma
- Supratentorial PNET
- Neuroblastoma metastatic to brain tissue
- Pilomyxoid variant of pilocytic astrocytoma

Helpful Clues for Common Diagnoses

Pilocytic Astrocytoma
- Low density on NECT
- High signal on T2
Medulloblastoma (PNET-MB)
- Hyperdense 4th ventricle (V) mass on NECT
- Restricts on DWI
Ependymoma
- 60% posterior fossa
  - “Plastic” tumor in 4th ventricle, extrudes through foramina
- 40% supratentorial
  - Mixed cystic, solid mass with Ca++
Pediatric Brainstem Glioma
- Location predicts pathology, prognosis
  - Infiltrating pontine glioma worst
Low-Grade Diffuse Astrocytoma
- Hemispheres, thalami (can be bithalamic), tectum, brainstem (pons, medulla)
  - 50% of brainstem “gliomas” are low grade, diffusely infiltrating astrocytomas
- Poorly marginated
- Hypo- on T1WI, hyperintense on T2WI
- No enhancement
Subependymal Giant Cell Astrocytoma
- Location at foramina of Monro typical
- Look for cortical/subcortical tubers
- Look for subependymal nodules
DNET
- Almost all in patients < 20 years
- Chronic epilepsy
- “Bubbly” appearing, cortically based mass
- “Ring” sign on FLAIR
Craniopharyngioma
- Nearly half of pediatric suprasellar masses
- 90% Ca++/cystic/enhance

Helpful Clues for Less Common Diagnoses

Germinoma
- Suprasellar + pineal masses together best clue
- Early ependymal infiltration
Choroid Plexus Papilloma
- Densely enhancing
- Cotyledon- or frond-like surface
Neurofibromatosis Type 2
- If multiple schwannomas, think NF2+
- Look for “hidden,” dural-based meningiomas with C+
Pineoblastoma
- Restricts on DWI
- Look for CSF spread (ventricles, ependyma)
Pleomorphic Xanthoastrocytoma
- Cortically based tumor (temporal lobe most common site)
- Dural reaction (“tail”) common
- Enhancing ill-defined mass plus cyst
Anaplastic Astrocytoma
- Diffusely infiltrating
- Classic do not enhance
Glioblastoma Multiforme
- Typically arises from lower grade astrocytoma
Gliomatosis Cerebri
- Less likely to enhance
- More likely bilateral
- More likely to spread across callosal tracts
Supratentorial PNET
- Infant with large, bulky, complex hemispheric mass
- Ca++, hemorrhage, necrosis common
- Peritumoral edema sparse/absent
Teratoma
- Neonate with large bulky midline mass
- Ca++, soft tissue, cysts, fat

Helpful Clues for Rare Diagnoses

Astroblastoma
- Large, hemispheric
- Well-circumscribed
- “Bubbly” solid and cystic
Choroid Plexus Carcinoma
- Similar to CPP
  - Invades ependymal surface and brain
  - Less homogeneous than CPP
Atypical Teratoid-Rhabdoid Tumor
- Heterogeneous intracranial mass in infant
- 50% infratentorial, early CSF spread
Metastases
- Pial, leptomeningeal
  - PNET
  - Ependymoma
  - Anaplastic astrocytoma
  - Germinoma
  - Choroid plexus carcinoma
- Falx
  - Leukemia involves both sides of falx
- Bone and dura: Neuroblastoma > leukemia
  - CT: Bone spiculation, “hair on end”
  - MR: Bone expanded and marrow replaced
Central Neurocytoma
- “Bubbly” lobulated mass in body of lateral ventricle
  
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Tags: EXPERTddx: Pediatrics

Aug 10, 2016 | Posted by drzezo in PEDIATRICS | Comments Off

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