Pediatric Supratentorial Brain Tumors

Dr. Prashant PoteJr.IIIDepartment of Radiology

Overview:

Pediatric brain tumors(PBT) are 15-20% of all brain tumors. Second most common pediatric tumor next to leukemia.

Overall, supratentorial and infratentorial tumors occur in equal frequency. Supratentorial more common <2yrs; infratentorial more common 4-10 yrs; equally common after 10yrs age

Classification

Posterior fossa Supratentorial Intraparenchymal Sellar/SuprasellarExtra-axial

Supratentorial-Intraparenchymal Astrocytoma Ependymoma Desmoplastic Infantile Ganglioglioma (DIG) Dysembryoplastic neuroepithelial tumor

(DNET) Teratoma Ganglioglioma/Gangliocytoma Primitive Neuroectodermal Tumor (PNET) Atypical teratoid/rhabdoid tumors

Supratentorial: Sellar/Suprasellar Craniopharyngioma Astrocytoma Rathke cleft cyst Germ cell tumors Hypothalamic hamartoma Langerhans cell histioctyosis Pituitary adenoma

Supratentorial- Extra axial Choroid plexus papilloma /carcinoma Langerhans cell histiocytosis Epidermoid/Dermoid Arachnoid cyst Metastasis

Custom differential diagnosis

Brain tumours in infancy (i.e. under one year of age)

1. Teratoma.2. CNS PNET3. Choroid plexus papilloma4. Anaplastic astrocytoma5. DIG

Cortically-based tumors• DNET• Ganglioglioma• Oligodendroglioma• PXA

Intraventricular tumors Ependymoma, subependymoma Central neurocytoma Choroid plexus papilloma/carcinoma

Pineal region tumors• Pineal parenchymal tumors

(pineocytoma/blastoma)• Germ cell tumors (germinoma,

teratoma, etc)

Dural-based tumors and mimics• Meningioma• Metastasis• Inflammatory pseudotumor• Infection (e.g., tuberculosis)• Extramedullary hematopoiesis

Local intracranial extension from extracranial neoplasms

• Chordoma• Paraganglioma• Carcinomas (e.g., nasopharyngeal

squamous cell),sarcomas (rhabdomyosarcoma)

Neoplasms that often have cyst + nodule

• Pilocytic astrocytoma• Ganglioglioma• Hemangioblastoma• Craniopharyngioma

Supratentorial Tumors Astrocytoma 30% of hemispheric tumors. Most

common cerebral hemispheric tumor Peak incidence at 7-8yrs age Low grade astrocytomas more common Glioblastoma Multiforme (GBM) WHO

IV/IV ~ 20% Typically involve basal ganglia,

thalamus Can be multi-centric

Juvenile pilocytic astrocytoma Cerebellum is most common site followed

by in and around optic nerve/chiasm, hypothalamus/third ventricle.

Cerebral hemisphere –uncommon. Cerebellum and cerebral Tm: cyst with

mural nodule. Optic nerve/chiasm/third ventricle: solid

infiltrating. Hemorrhage uncommon; if present its

pilomyxoid astrocytoma

Juvenile pilocytic astrocytoma

Sagittal T2WI shows amixed solid and cystic focal lesion in theright frontoparietal region (arrows). Thesolid component of the lesion has intermediatesignal, and the cystic component hashigh signal.

Sagittal postcontrast T1WIshows prominent Gd-contrast enhancementat the solid component of the lesion

Juvenile pilocytic astrocytoma

Post contrast

Supratentorial Tumors Pilomyxoid Astrocytoma Differs from PA in clinical course,

presentation and histological appearance. 60%- suprasellar, 40%cerebral hemisphere Cerebellum and fourth ventricle ;rare Age: Suprasellar- infants and children <4 yrs Atypical location – adolescent and in

adults Imaging: A large H shaped suprasellar mass,

mixed SI, heterogeneous enhancement with hemorrhage

Supratentorial Tumors Pilomyxoid Astrocytoma

Subependymal Giant cell (SEGA):

First two decades of life, mean age 11 yrs

An enhancing lesion at foramen of Monro should be considered SEGA until proven otherwise.

Calcification, TSC other feature; SEN, cortical

tubers, white matter radial migration lines

SEGA or SEN; progressive enlargement.

Tuberous Sclerosis- SEGAT2Post contrast T1

Pleomorphic Xanthoastrocytoma (PXA)

Children and young adults, 2/3rd under 18 yr

Well delineated cortically based mass that contacts the leptomeninges

70%; cyst with nodule, 30% solid with intratumoral cysts

Calcification 40%, hemorrhage rare Moderate enhancement of Tm

nodule post contrast

Pleomorphic Xanthoastrocytoma (PXA)

Supratentorial Tumors Ependymoma 30% of ependymomas Peak incidence between 1-5yrs age Histologically similar to infratentorial

ependymomas – fourth ventricle and CPA.

Differs! typically in periventricular white matter and cerebral hemisphere parenchyma.

Ependymoma

Axial T2WIshows a lesion with heterogenous high signalcontaining a cystic zone in the inferiorright frontal lobe.

Postcontrast axial T1WIshows irregular peripheral enhancement atlesion.

Desmoplastic Infantile Astrcytoma/Ganglioglioma (DIG)

Arises from subpial astrocytes Found between1-months age

w/peak at 3-6 months. Occasionally seen up to 5yrs

Cortically based tumor nodule.

Post contrast T1

Desmoplastic infantile gangliogliomaT1

Desmoplastic Infantile Gangliogioma Imaging findings: Large cyst w/cortically based enhancing

tumor nodule Solid component avidly enhances;

leptomeningeal and dural enhancement, enhancement

Occupies majority of cerebral hemisphere Looks worse than it is!! Greater then 75% survival after 15yrs

w/complete resection

Dysembryoplastic Neuroepithelial Tumor (DNET) Cause of 20% cases of medically

refractory epilepsy 60% in temporal lobe, 30% frontal

lobe Solid and cystic tumors Scalloping of inner table skull Associated w/cortical dysplasia Slow to No growth!

Dysembryoplastic Neuroepithelial Tumor (DNET

•Multicystic cortically based lesion •25% have calcifications •20-40% enhancement•Characteristic “bright rim”on FLAIR .•Usually no edema, no mass effect.

FLAIRT2T2

Post contrast T1

DNET

Ganglioglioma/Gangliocytoma Found in adolescents Associated with mesial temporal

sclerosis Most common in temporal, parietal, frontal lobes

Difference between GG and GC is histological

Clinical: Partial complex seizures

Ganglioglioma/Gangliocytoma

Imaging findings:

•Solid or cystic or cyst w/mural nodule •Variable enhancement•35% w/calcifications •If peripheral location, then scalloping of adjacent calvarium•Hemorrhage and necrosis absent

GRE Post contrast T1

Ganglioglioma

Ganglioglioma

Primitive neuroectodermaltumor.

a Axial T2WI shows a large lesionwith heterogeneous high signal in the rightfrontal lobe extending across the corpuscallosum to the left frontal lobe

b Postcontrastsagittal T1WI shows irregular enhancementin a portion of the lesion.

Primitive neuroectodermaltumor (sPNET) occur in the paediatric population,

usually during the first 10 years of life, Circumscribed or invasive lesions. Low to

intermediate signal on T1WI; intermediate to high signal on T2WI.

Variable Gd-contrast enhancement. Frequent dissemination into the

leptomeninges. Highly malignant tumors located in the

cerebrum,pineal gland, and cerebellum.

Supratentorial Tumors Teratoma

2-5% of tumors in children less then 15 yrs

Midline lesion typically in pineal gland, third ventricle

Most are benign

Supratentorial Tumors Teratoma Imaging findings: Midline mass with calcifications and

fat Enhancement of soft tissue

components Malignant teratomas have more

vasogenic edema, irregular, less well defined.

CT- Teratoma

Teratoma

CT- Teratoma

Supratentorial Tumors Extra-axial Choroid plexus papilloma /carcinoma Langerhans cell histiocytosis Epidermoid/Dermoid Arachnoid cyst Metastasis

Choroid plexus papilloma /carcinoma

Arise from epithelium of choroid plexus 5% of supratentorial tumors Typically age 1-5yrs Male predominance Most common in trigone of left lateral

ventricle CPC more irregular and invasive then

CPP but diagnosis is histological Clinical: Hydrocephalus

Choroid plexus papilloma /carcinoma

Imaging: CPP is lobulated, homogeneous mass

with frond like excrescence. Punctate calcifications, hyperdense

on CT Intense enhancement on CT/MR CPC irregular, heterogeneous

w/cystic necrosis, invasive and vasogenic edema

T2 Choroid plexus papilloma

Post contrat T1

Choroid plexus papilloma -CT

Choroid plexus papilloma

T2 Post contrat T1

Choroid plexus carcinoma

Epidermoid

T2

Post contrast T1

FLAIR

DWI

Sellar/Suprasellar Craniopharyngioma Astrocytoma Rathke cleft cyst Germ cell tumors Hypothalamic hamartoma Langerhans cell histioctyosis Pituitary adenoma

Common Presentations of Hypothalamic and Pituitary Lesions

Hypopituitarism– craniopharyngioma Diabetes insipidus – LCH, Precocious puberty– hamartoma of

tuber cinereum, hypothalamic glioma

Amenorrhea– pituitary adenoma, Rathke cleft cyst

Craniopharyngiomas

Thought to arise from remnant of craniopharyngeal duct.

Adamantinomatous(children) and papillary (adults) types

15% supratentorial tumors, 50% suprasellar tumors

2 peaks: 10-14 yrs age; 4th to 6th decade of life

Rim enhancement of cysts; heterogeneous enhancement solid portions

Craniopharyngioma

Rathke Cleft cyst

Benign epithelial lined cyst in sella Arises from remnants of Rathke

pouch in pituitary gland with frequent suprasellar extension.

Rare in children

Imaging findings:

CT: Cystic nonenhancing,noncalcified mass

MRI: T1 or T2 hyperintense No enhancement

T1

Post contrast T1

Astrocytoma

Suprasellar type arises from optic chiasm or hypothalamus

M=F 4yrs age 30-50% have family history of NF1 Clinical: Hydrocephalus, decreased

vision, pituitary dysfunction (short stature)

Astrocytoma

Imaging findings: T2, FLAIR hyperintense Fusiform or lobulated enlargement

optic nerves with heterogeneous enhancement

Gliomas in patients without NF1 have cystic components.

POST Contrast T1

T2 T1

Supratentorial Tumors Germ cell tumors Imaging findings: MR: Infundibular thickening

w/uniform enhancement Iso to hypointense on T1, T2 and

FLAIR When large, can have areas of

cystic necrosis REMEMBER: HIGH ASSOCIATION

W/DIABETES INSIPIDUS!!.

Supratentorial Tumors: Germ cell tumors

Supratentorial Tumors Hypothalamic Hamartoma

Heterotopic gray matter generally located in tuber cinereum

Can originate from floor third ventricle, mamillary bodies.

Can be sessile or pedunculated Large lesions cause gelastic seizures;

small lesions have precocious puberty Found in 33% of patients w/precocious

puberty

Supratentorial Tumors Hypothalamic Hamartoma

MR: Isointense on T1, slightly hyperintense on T2, Non enhancing

Hypothalamic hamartoma

Post contrast T1