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Neuroblastoma mets to brain

12-14 mths after initial Dx . Solid or cystic.
Can enhance, hemorrhage, calcify.
Can involve leptomeninges
Higher risk with
MYCN gene,
bone marrow involvement,
LP at dignosis,
Young age 2-3.

Lymphoma mets to brain

Brain and abdomen involvement is very rare

Differential of restricted diffusion

Infarct
Neurotoxic chemotherapy
Radiation
Artifact

CNS complications in ALL

Chemotherapeutic agents
CNS radiation
Coagulopathy
Marrow transplantation
Immunodeficiency

Methotrexate CNS complications

Intrathecal or systemic
No specific age group
Restricted diffusion resolves whith symptoms
Hemiparesis and aphasia most common
Long term leukoencephalopathy.

Cord herniation

Cord herniates through dura.
Typically ventral and midthoracic.
Brown-Sequard is most common symptomotology
Can be idiopathic, iatrogenic, traumatic.
MRI best, then CT myelo to differentiate from arachnoid cyst.
Treat by surgery with reduction-some improvement even in chronic cases.

Carotid artery dissection

Often overlooked cause of ant. circ. infarcts
Peak at 50s. Healthy individuals.
Prediposition from hypertension, Ehlers-Danlos disease, Marfan syndrome, fibromuscular dysplasia, migraine, oral contraceptives, and pharyngeal infections.
Often a history of minor trauma (chiropractic, yoga, ceiling painting, nose blowing, judo, coughing, sneezing, vomiting)
Often a mural hematoma, so no flap seen, no contrast in false lumen.
Use fata-sat to highlight methemoglobin in hematoma.
Treat with anticoags and aspirin.

Cappilary telangeactasia

Capillary malformation with normal surrounding brain tissue.
Occult on angiography because of small vessel size and slow flow.
Have no Ca, Gliosis, hemorrhage and so do not show up on FLAIR, T1, T2
Best visualized with Gad and susceptibility imaging on MR
Most are asymptomatic
Most common location is Pons, midbrain.

Uveal melanoma

Most common primary ocular malignancy adult
Rare in children.
Characteristic collar button configuration tif erupts through Bruch's membrane
Solid well defined,
Variable MRI appearance depending on melanin content. Moderate enhancing.
Highly vascular hypoechoic on US.
Can happen in any section, Iris, ciliary body, choroid.
Mets hematogenously to liver, lung, bone, kidney, and brain in that order.
>10mm enucleate. 3-10mm radiation and brachytherapy. <3 mm may be benign nevi, so monitor and biopsy.

Arachnoid cyst

Results from splitting of meninges and then trapping of CSF inside the new space.
Most common location is middle cranial fossa.
Follows CSF signal on all signal (suppresses on FLAIR, unlike epidermoid)
Usually asymtomatic, but can cause symptoms by mass effect.

POEMS syndrome

Polyneuropathy, Organomegaly, Endocrinopathy or Edema, M-protein and Skin abnormalities (hyperpig)
AKA Crow-***ase syndrome, Takatsuki disease, or PEP syndrome
Combination of a plasma-cell proliferative disorder (typically myeloma), polyneuropathy, and effects on many other organ systems.
Average age at onset is 50 2:1 M:F
Clinical features
Polyneuropathy is usually symmetrical and distal
Demyelination and axonal damage, sensory, motor
autonomic neurones are all affected
Myeloma
Pappiledema
Organomegaly
liver
spleen
nodes
Edema
Endocrinopathy: In women, amenorrhoea, and in men,
gynaecomastia, erectile dysfunction and testicular atrophy
M-protein=monoclonal IgG or IgA, in 75-80%
Skin changes, lots of variations. Clubbing.

Pineal cyst

Well defined cyst in pineal region
Usually <1cm and asymptomatic
3:1 F:M most commonly diagnosed in 30s.
Expansion very rare.
>10mm needs follow-up as can sometime enlarge
Symptoms from mass effect-aqueduct compresstion
Can rim enhance, look for thin even rim. Thick/nodudlar=pineocytoma
Hemorrhage may result in rapid expansion=pineal apoplexy
Imaging
Follows proteinaceous fluid characteristics. Variable
depending on exact content.
Contrast may eventually diffuse in, so beware late imaging
Differential
Pineal tumor
pineocytoma
pineoblastoma
Epidermoid cyst
Arachnoid
Germ cell tumor
germinoma
embryonal carcinoma
choriocarcinoma
teratoma
Mets

Warthin Tumor

Warthin tumor arises in incorporated lymphoid tissue.
60 years mean age at presentation
M:F 3:1
Benign, slow-growing
Malignant transformation in <1%
Recurrent likely from incomplete resection

Associations
Smoking (90% of tumor presentation in smokers)
Radiation exposure
Multiple lesions or bilateral, think Epstein-Barr virus.
Autoimmune disorders

Imaging characteristics
PEARL - Sharply demarcated round/oval mass with
profound intraparenchymal inhomogeneity
Most are intraparotid within the parotid tail
2-4 cm in diameter
No calcification
30% cystic
Minimal enhancement of solid component
MR
PEARL - MR with contrast best for determining location
T1 - Hypo intense in both solid and cystic component
T2 - INTERMED->Hyper intense in solid component and
hyper in cystic component
T1 C+ - Minimal enhancement of solid component
US
Anechoic mass with inhomogeneous pattern

Epidemiology
2nd most common benign parotid gland tumor
20% multicentric, unilateral or bilateral, synchronous or
metachronous
5-10% in upper neck or peri-parotid

Subependymal giant cell tumor

WHO grade 1 tumor occurs in 15% of Tuberous sclerosis
Present with mass effect (headache, vomiting, obtundation) due to foramen of Monro obstruction and hydrocephalus.
Mean age is 11 years
Seeding is rare
Survey until resection is necessary
MR
Iso to gray matter on T1
Hyper to gray on T2 and FLAIR
Calcium may lead to hypointensity (hyperdense on CT)
Avid enhancing
Pretty much impossible to differentiate from subependymal nodule.

Cranial Ewing's

Rare, only 1% of Ewing carcinomas
More often involves frontal and parietal bones.
Onion skin appearance less likely (as opposed to long bones)
Diffuse permeative destruction of inner AND outer table (as opposed to Histio X which has differential destruction)
Large, avidly enhancing complex extradural mass.

Oligodendroglioma

Well differentiated, heterogeneous appearing.
Slow growing
Diffusely infiltrating
Calcifications common
Cystic degeneration common, hemorrhage is not
Mostly frontal cortex, rare in ventricles and cerebellum, even more rare in stem and cord
Peak incidence 4-5th decades.
Most common symtoms Seizure and Headache
Resection is tratment of choice.

Basilar invaginaation

Upward protrusion of the odontoid process into the infratentorial space more than 3 mm above Chamberlain's line 4.5 mm above McGregor's line.

Congenital causes
Down's
Klippel-Feil
Chiari malformations
Also associated with syringohydromyelia, atlas occipitalization,
platybasia.
Called Basilar Impression when acquired
Paget's
RA
Hyperparathyroid
Osteomalacia
Osteogenesis imperfecta

Classic symptoms
Upper cervical cord comression syndrome (labile BP, Arrhythmias)
Hydrocephalus
Headache
Posterior skull pain

Treatment is surgical, though some asymptomatic patients can be treated conservatively.

Myxopappilary ependymoma

•Slow-growing tumor arising from the ependymal cells of the filum terminale.
•Occurs almost exclusively in conus medullaris, filum terminale, and cauda equina.
•13% of all spinal ependymomas
•More common in males (M:F=2:1) with a
•Mean age of 35 at diagnosis
•Does have drop mets, but not as frequently as other types.
•Typical presentation
back pain,
paraparesis,
radiculopathy, and
occasionally bowel and bladder dysfunction
•Typical imaging features
markedly enhancing intradural tumor with
heterogeneity due to hemorrhage,
calcification and cysts.
Span two to four vertebral segments, and
Well-circumscribed intradural masses.
T1 isointensity, T2 hyperintensity, and
Avid enhancement on post-contrast images.
• Surgical resection usually curative.
• Rads and chemo for mets.

NAA NMR peak

2 ppm
Active neurons
Low in neoplasms that destroy neurons and demyeliniation

Creatinine NMR peak

3 ppm

Choline NMR peak

3.2 ppm
Cellular turnover.
High in neoplasms and demyelinating disease due to cell membrane turnover

Lateral corticospinal tract

Motor to contralateral muscles
Motor cortex-coronoa radiata-post limb int capsule-cerebral peduncle-medulla decussation-posterolatera cord.

Anterior corticospinal tract

Motor to ipsilateral muscles
Primary cortex-corona-posterior int caps-peduncle-central pons-medulla no decussation-anterior funiculus and ant column of cord.

Rubrospinal tract

Motor to contralateral limbs
Red nucl-Decussation in ventral tegmentum-Lateral funiculus-posterolateral cord white matter lateral to corticospinal tract

Reticulospinal tract

Automatic movements (strethc, walk, head coordination)
Pons-medulla-ipsilateral anterior column in cord.

Vestibulospinal tract

Balance, posture, head coordination

Medial lemniscus

Touch and limb position
Posterior WM-medulla dorsal nuclei-decussation-medial lemniscus-thalamus-anterior capsule-primary sens cortex

Spinotholamic tract

Pain and temperature
Dorsal horn-spinal decussation-anterolateral spinal tract-pons reticular formation-medulla-thalamus

Lateral lemniscus

Auditory
Auditory in caudal pons-crossed and uncrossed to inferior colliculus-medial geniculate-priomary aud cortex.

Optic tract lesions

nerve-all vision from ipsilateral eye
optic chiasm-bitemporal hemianopsia
tract- contralateral field defect (all right or all left)
radiation-various contralateral regions-Superior radiation in parietal lobe=lower visual field, inferior fibers (meyer's loop) anteroinferior to lat ventricle=upper field.
Visual cortex-entire contralateral field except fovea.

Origins of vranial nerves

1-4 from mmidbrain
5-8 from pons
9-12 from medulla

CN III

III nucl just posterior to red nucl.
Passes PCOM, susceptible PCOM aneurysms.
To orbit through sup. orbital fissure.
Edinger -Wesphal nucleus controls nucleus.

CN IV

Trochlear
Nucl in midbrain just below that of 3rd CN
Contralateral interconnections in meidal longitudinal lemniscus.
Unique posterior exit and complete crossover.
To orbit through sup fissure.
Supplies superior oblique.

CN V

Nucleus medial to middle cerebellar peduncle.
Exits laterally, synapses in Meckel's cave gasserian ganglion, then trifurcates.
V1, ophthalmic, runs inferiorly in cavernous sinus, enters in superior fissure. Supplies upper face, lacrimal gland, eye, nose.
V2 goes through foramen rotundum, runs in pterygopalatine fossa. Supplies maxillofacial region. Maxillary nerve branch goes into inferior fissure.
V3 Mandibular, supplies mastication muscles motor, lower face, ear sensory, TMJ, tympanic membrane.
Trifurcates to auriculotemporal, lingual and inferior alveolar nerves.

CN VI

Abducens
Nucleus in middle of pons near floor of 4th ventricle.
Leaves anteriorly at junction of pons and pyramids. Goes through Dorello's canal, then cavernous sinus, where it is susceptible to compression by carotid.

CN VII

Facial
Nucleus in midpons anterolateral to abducens.
Fibers circle abducens nucleus before exiting anteriorly. Crosses cerebellopontine angle cystern then into auditory canal (anterior superior).

CN VIII

Nucelui in superior medulla at base of inferior cerebellar peduncle. Cochlear division runs anterior inferior in auditory canal. Vestibular branches run posterior.

Cn IX

Nucleus in medulla posterior in inf olivary nucleus. Nucleus ambiguus for motor (shared with vagus), inferior salivary for spitting tractus solitarius for taste.
Fibers pass through olivary sulcus, pars nervosa of jugular foramen, through superior constrictor muscles. Innervate pharynx and stylopharyngeus muscles. Posterior 3rd of tongue. Supplies Jacobson's nerve among others.

CN X

Vagus
nuclei in medulla, nucleus ambiguus (shared with IX), Dorsal nucleus (just anterior to 4th ventricle), Nucleus solitarius. Exits medulla through olivary sulcus, out through pars vascularis of jugular foramen, runs in carotid sheath where it is susceptible to compression.

CN XI

Fibers from first 3 cervical levels and motor cortex. These make ansa cervicalis which runs up along carotid sheath then out jugular foramen. Supplies infrahyoid strap muscles, sternocleidomastoid, trapesius.

CN XII

Nucleus in paramedian area of 4th ventricle anteriro wall in medulla.
Exit anteriorly in preolivary sulcus. Goes through hypoglossal canal Supplies intrinsics of tongue, genioglossus, styloglossus and hyoglossus.

Branches of ECA

In anterior to posterior order, numbers are by prox to distal
1 Superior thyroid
2 Linguial
4 Facial
6 Maxillary
7 Superficial temporal frontal and parietal
6 Posterior auricular
5 Occipital
3 Ascending pharyngeal

Persistent trigeminal artery

Origin from cavernous carotid. Feeds top of basillar. Runs in suprasellar cystern. Prone to aneurysms.

Persistent Otic artery

Origin from petrous carotid. Feeds mid basilar. Runs in internal auditory canal.

Persistent hypoglossal artery

From high cervical ICA at skull base. Feeds intracranial vertebrobasilar. Runs in hypoglossal canal.

Persistent proatlantal type 1 artery

Origin at low ICA. Feeds cranial and cervical vertebrobasilar. Runs at C2 level.

Persistent Proatlantal type 2 artery

Origin from external carotid. Feeds same as type 1
Associated with hypoplastic vertebral arteries.

Branches of vertebral arteries

Muscular
Occipital
Segmental spinal
Anterior spinal, supplies most of the cord.
Posterior meningeal.
First branch in intracranial compartment is the PICA

Basilar artery branches

AICA
Superior cerebellar.
Terminates as the two PCAs most of the time.

Cribriform plate

Contents: Olfactory nerves.
Diseases: Esthesioneuroblastoma

Optic canal

Contents: Optic nerve, Ophthalmic artery
Diseases: Optic nerve gliomas, meningniomas

Superior orbital fissure

Contents: Oculomotor, trochelar, abducens, V1. Ophthalmic veins, sympathetic nerve plexus, small arteries

Foramen rotundum

Contents :Maxillary (V2)
Diseases: Schwannomas, Meningiomas, PNS

Foramen ovale

Contents: Mandibular (V3), lesser petrosal nerve, small arteries, emissary veins.
Diseases: Schwannomas, Meningiomas, PNS

Stylomastoid foramen

Contents: Facial nerve, stylomastoid artery
Diseases: PNS, Bell's palsy, schwannoma

Internal auditory canal

Contents: CN VII and VIII, labyrinthine artery
Diseases: Schwannomas, meningiomas, epidermoids, archnoid cysts.

Jugular pars nervosa

Contents: CN IX, inferior petrosal sinus
Diseases: Schwannoms, meningiomas, PNS

Jugular pars vscularis

Contents: CN X, CN X1, IJ, small arteries.
Diseases: Glomus tumors, Schwannomas, meningiomas, PNS, mets.

Hypoglossal canal

Contents: CN XII, emissary vein, small arteries (persistent hypoglossal artery, when it is present at all)
Diseases:
Chordoma
Large glomus jugulare
Meningioma
Mets
Myeloma
Neuroma
Neurotropic spread of tumor
Schwannoma

Foramen magnum

Contents: Spinal cord, vertebral arteries, spinal arteries and nerves
Diseases: Meningniomas, chordomas, schwnnomas.

Foramen spinosum

Contents: Middle meningeal artery/vein, meningeal V3 branch, lesser superficial petrosal nerve.
Diseases: ?

Foramen lacerum

Contents: Carotid artery and vidian nerve cross over it. Greater petrosal nerve.
Diseases: PNS

Incisive canal

Contents: Nasopalatine nerve, palatine arteries
Diseases: cysts

Greater palatine canal

Contents: Greater palatine nerve, palatine vessels
Diseases: PNS

Carotid canal

Contents: ICA, sympathetic plexus.
Diseases: PNS

Foramen of Vesalius

Inconstant emissary foramen anterior and medial to foramen ovale.
Contents: Emissary veins
Diseases: aneurysms

Petrosal foramen

Contents: Lesser petrosla nerve
Diseases:

Foramen cecum

Contents: Emissary vein
Diseases:

Vestibular aqueduct

Contents: Endollymphatic duct, meningeal branch of occipital artery
Diseases: Meniere's disease, congenital stenosis, patulousness

Condylar canal

Contents: Emissary vein, meningeal branch of occipital artery
Diseases:

Mastoid foramen

Contents: Emissary vein, meningeal branch of occipital artery
Diseases:

Palatovaginal canal

Contents: Pharyngeal branches of pterygopalatine ganglion and maxillary artery
Diseases: PNS

Cochlear aqueduct

Contents: Perilymphatic duct, emissary vein
Diseases: Congenital stenosis or patulousness

Inferior orbital fissure

Contents:Maxillary nerve, zygomatic nerve, orbital pterigopalatine branches, infraorbital vessels, inferior ophthalmic veins
Diseases: PNS, Schwannomas

Infraorbital foramen

Contents: Infraorbital nerve and vessels
Diseases: blow-out fractures

Mental foramen

Contents: Mental nerve and vessels
Diseases: Squamous cell carcinoma

Mandibular foramen

Contents: Inferior alveolar nerve and vessels
Diseases: Schwannomas, Squamous cell carcinoma

Pterygomacillary fissure

Contents: Maxillary artery, Maxillary nerve, sphenopalatine veins
Diseases: Juvenile andiofibromas

Vidian canal

Contents: Vidian nerve and artery
Diseases: PNS

Meningothelial origin tumors

Meningioma
Meningothelial
Fibrous
Transitional
Psammomatous
Angiomatous
Microcystic
Secretory
Metaplastic
Clear cell
Chordoid
Atypical
Papillary
Rhabdoid
Anaplastic meningioma

Mesenchimal origin tumors

Lipoma
Angiolipoma
Hibernoma
Liposarcoma
Solitary fibrous tumor
Fibrosarcoma
Malignant fibrous histiiocytoma
Leiomyoma
Leiomyosarcoma
Rhabdomyoma
Rhabdomyosarcoma
Chondroma
Chndrosarcoma
Osteoma
Osteosarcoma
Osteochondroma
Hemangioma
Epithelioid hemangioendothelioma
Hemangiopericytoma
Angiosarcoma
Kaposi Sarcoma

Melanocytic origin tumors

Diffuse melanocytosis
Melanocytoma
Malignant melanoma
Meningeal melanocytosis

Meningioma

Tumor of meningeal origin
Frequent imaging findings
Dural tail
Adjacent ostolysis or hyperostosis
Obtuse angle with dura
Calcification about 20%
Unifrom enhancing
Alanine peak on MRS
Hyperdense on CT
Cysts, Hemorrhage, Axt into auditory canal are rare.
Skull base meningiomas may require embolization prior to resection
May encase and comress adjacent vessels.
Atypical type is WHO grade II. By pathology only, imaging is identical.
Malignant type is WHO grade III, rare, diagnosed by atypical behavior (rapid expansion, intraparenchymal ingrowth)
Rad induced type is most common rads induced tumor. About 35 year latency mean.

Schwannoma

Tumor of Schwann cell origin
Frequent imaging findings
Acute angle with dura
Cysts in about 10%
Often inhomogeneous enhancement
Often extends into auditory canal
Taurine and/or GABA peak on MRS
Isodense on CT
Dural tail, Bony reaction, Calcification, hemorrhage are rare.

Hemangiopericytoma

Meningeal mesenchymal tumor deriving from smooth muscle pericyte cells.
More agressive than most meningiomas with higher recurrence.
Frequent imaging
Mostly large, over 4 cm,
extraaxial,
supratentorial,
hyperdense,
enhancing
Hyperostosis or coacification is rare.

Meningioangiomatosis

Rare
Associated with NF II
Usually in cortex, but about 10% are meningeal
Slow
Calcifications frequent
Proliferating vessels

May present with seizure in young pt.

Neurogenic tumors

Schwannomas
Neurofibromas
Neuromas

All look alike on imaging, path necessary for diagnosis.

Cellular schwannomas

Antoni A cells presominate
Likes CN V VI pelvis, retroperitoneum, mediastinum

Plexiform Schwanomas

Found in skin, subcutaneous soft tissues
associated with NF 2

Melanotic schwannomas

Pigmented
Younger population
Like spinal nerves over cranial.

Cerbellopontine angle masses

Vestibular schwannoma (75%)
Meningioma (10%)
Epidermoid (5%)
Facial nerve schwannoma (4%)
Aneurysm
Vert, basilar, posterior, PICA
Brain stem glioma
Arachnoid cyst
Paraganglioma
Hematogenous metastasis
Subarachnoid spread of tumor
Lipoma
Hemangioma
Choroid plexus papilloma
Ependymoma
Desmoplatic medulloblastoma

Neurofibroma

Specifically associated with NF 1
Mostly in skin and subcutaneous soft tissues (the skin tags)
Contain mixed cells, schwann, perineural, fibroblasts etc.
Antoni A or B can predominate.
Plexiform type can occur (again, NF 1)

Neuroma

Post-traumatic proliferation of nerve cells. Not a real tumor.
No perinueral lining or fibroblastic tissue.
Can occur after nerve avulsion (C-spine)
Operative beds
Limb ammutation.
Look like small schwannomas on imaging.

Dural mets

Predominantly
Lung
Breast
Prostate
Melanoma
Chunky thickening of dura on imaging.
Can even spread on top of meningioma.
Subarachnoid seeding
Breast
Lung
Most common locations for SAS
Basal cysterns.
Interpeduncular cystern
Cerebellopontine cystern along CNs
Over convexities.

Choloroma

Granulocyte sarcoma
Tumor of immature granulocytes associated with myelogenous leukemias.
Can occur anywhere, often predates the leukemia.
Orbit and epidural space most common in CNS
Imgaing
Prominent vasogenic edema
T2 intermediate
Enhancing
Radiosensitive.

Choroid plexus papilloma

What it says. WHO I
Most present before 5 years. up to 20% in 1st year.
In children 90% are in lateral ventricle antrum.
In adults most are in 4th ventricle.
Overall lateral, 4th, 3rd, ceerebellopontine angle.
SV40 virus implicated.
Presents with hydrocephalus and papilladema by CSF overproduction or obstruction.
Can be present a foramen of luschka (extension)
Can calcify.
CT
Hyperdense mullbery.
MRI
Low T1, mixed T2. Enhance dramatically. Flow voids.
100% survival at 5 years for complete resection.

Choroid plexus carcinoma

WHO grade III
Rare compared to papillomas. About 10-20% degen. rate.
Lateral ventricles predominantly.
CSF dissemination in 60%
Can't really distinguish from benign papillma on imaging. Look for parenchymal invasion
40% survival at 5 years even with complete resection.

Choroid Plexus hemangioma

Benign.
Usually in lateral ventricle
Enhances markedly.
Can calcify.
Some association with Sturge-Weber syndrome (often ipsilateral to vascular malformation in this case)

Choroid plexus xanthogranuloma

Centered on glomus in lateral ventricle
May have fat density in it.
Often bright on DWI

Choroid plexus neoplasms

Papilloma
Carcinoma
Ependymoma
Hemangioma
Lymphoma
Meningioma
Mets

Epidermoid CNS cyst

Arise from rest of epidermoid tissue resulting in collection of keartin, cholesterin epithelium debris (white cheesy stuff)
Slow growing.
Peak incidence 20 to 40
Most often in
cerebellopontine cystern (trigeminal neuralgia, facial paralysis)
Suprasellar
Prepontine cystern
Pineal region
Extradural much less common tha intradural in which case
Diploic space
Petrous bone
Temporal bone
Weel defined bony lesion with sclerotic margins
CT
Low density, but not fat
No bone or calcification
Expand to fill available spaces
Typically do not enhance, but may have a bit of wall enhancement.
MR
T1 hypo, T2 hyper like water, but Bright on FLAIR
Usually very bright on DWI

Dermoid cyst

Arises from rest of dermoid cyst.
May have hair follicles, sebacious glands etc.
For that reason has high fat signal and calcifies
Typically in midline as opposed to epidermoids.
Younger and more male patient set
Look for phase shift on MRI to prove fat.
Can rupture causing multiple fat droplets all over.

CNS Teratoma

Rests of all three tissue layers.
Pineal and suprasellar cysterns most common locations
Mixed density or intensity lesion. Often gross fat present.
Look for peripheral enhancing nodule to differentiate from dermoid (not a sure thing)

CNS Lipoma

Not true neoplasm.
Associated with agenesis of corpus callosum
60% association with a congenital anomaly of neural elements
Most common sites
Pericallosal
Quadrageminal plate cystern
Suprasellar
Cerebellopontine angle
Look for entirely fat signal and fat suppression on MR

Juvenile pilocytic astrocytoma

Most common juvenile infratentorial brain tumor. 60% in posterior fossa, but also like optic pathways and hypothalamus.
WHO grade I
Usually well defined, round.
Cystic with a mural nodule is classic, but may be solid.
MR
Hypo T1, Hyper T2/FLAIR
Cystic portion follows CSF characteristics.
Solid portion enhances strongly
PET
High metabolism
Compare to fibirillary astrocytomas: Less invasive, better prognosis, younger children. Also more frequent 85% vs 15%
When at hypothalamic-optic chiasm-3rd ventricle region, associated with NF (type ?)

Brain stem glioma

Infiltrates the brain stem and therefore can not be excised.
80% occur in childhood and comprise 20% of posterior fossa tumors.
Treatment is radiation.
WHO grade II, 25% survival at 10 years.
Pons is most common.
There is a tectal and exophytic type, with better prognosis.
MR is best
Hyper T2/FLAIR
About a third enhance.

Medulloblastoma/PNET

Comprise about 1/3 of posterior fossa t umors, 50% of cerebellar tumors.
Very malignant, WHO grade IV
Usually midline from vermis then growing upwards in kids.
More often lateral in cerebellum in older patients.
Typical age range is 5-12, m>f
Typically presents with hydrocephalus
Associated with Turcot's syndrome and Gorlin's syndrome
Melanotic type has worse prognosis.
High seeding rate
CT
Homogeneous hyperdense (as compared to ependymoma)
Displaces 4th ventricle inferiorly
Can calcify
Moderate enhancing
Can have cystic change
MRI
Hypo T1, iso T2
well defined
Not much edema
Can seed (sugarcoating) up to 50%
Hemorrhage uncommon
MRS
Low NAA:Cho ratio. Usually not lactate

Medullomyoblastoma

Look like regular medullablastoma. Myogenic features on histology.

Rhabdoid tumor

WHO grade IV, death within 1 year.
Highly agressive, heterogeneous, often hemorrhagic, necrotic, calcifications and cystic change.
Dense on CT, patchy enhancement
ABout 1/3 have subarachnoid dissemination.
About half in posterior fossa. 40% supratentorial, 5% peripheral. Multifocal or spinal is rare.

Ependymoma types

Cellular: WHO II, Peaks 0-9 and 30-50 (spinal)
Papillary: WHO II, Peak 0-9
Clear cell: WHO II, 0-9
Tanycytic, WHO II, 30-50
Anaplastic: WHO III, 0-9
Myxopapillary: WHO I, 30-40
Subependymoma, WHO I, 40-60

Ependymoma

Usually 4th ventricle when in posterior fossa. (can hang out of foramina)
About 20% intraparenchymal
Prognosis varies by site
Filum terminale best (WHO I)
Cord
Supratentorial space
Posterior fossa worst (WHO II)
About half calcify (typically punctate)
CT
Hypo to isodense
Mild enhancement.
Hydrocephalus.
CLASSIC: Calcified mass in 4th ventricle extending through Luschka and Magendie.
MRI
Hypo T1, Intermediate T2
Can have hemorrhage.
Hypointensity may reflect calcification
High rate of seeding.

Subependymoma

WHO grade 1
Look like ependymoma in every way except location.
Frequently multiple.
Most common location (lateral recess of 4th ventricle, then lateral ventricle and septum pellucidum
Lateral ventricular arise later in life (>15 or so)
Most do not enhance.
Isodense on CT and isointense on MRI

Cerebellar liponeurocytoma

Mean age 51
Gross fat can be seen.
Otherwise look like medulloblastomas.
Good prognosis

CNS hemangioblastoma

Most common primary intraparenchymal tumor in infratentorial space in adults. Pretty much the same lesion as JPA in children. Differentiate mostly by pt age.
WHO grade I, cured by resection.
83% in cerebellum, remainder is sp cord, medulla and cerebrum.
Much rarer than schwannomas and mets.
Young adults, M>F
Commonly present with headache, ataxia, nausea, vomiting, vertigo.
Ofter has polycythemia due to increased erythropoietin
25% associated with vHL
Typically cystic mass with solid mural nodule (60%)
Highly vscular-serpentine signal voids
Can be solid or purely cystic. Solid ones enhance avidly.

Manifestations of vHL

CNS
Hemangioblastomas
Cerebellar
Retinal
Spinal
Medullary.
Extraaxial
Renal
Cysts
Hypernephroma
Hemangioblastoma
Adenoma
Pancreas
Cysts
Adenoma
Adenocarcinoma
Islet cell tumor
Liver
Hemangioma
Cyst
Adenoma
Spleeen
Angioma
Adrenal
Pheochromocytoma
Cyst
Lung
Cyst
Bone
Hemangioma
Endolymphatic cell tumor
Cardiac
Rhabdomyoma
Epididymis
Cyst
Cystadenoma
Polycythemia

Mets

Most common neoplasm in brain overall.
Usually well defined with a lot of edema. Mostly near G/W junction.
Sources from
Lung
Bronchogenic most
Squamous least
Breast
Melanoma
RCC
Thyroid carcinoma
CT
Most are low density excepting calcifications, hemorrhage, proteinacious material
MRI
Variable appearance of T1 and T2
Vasogenic edema

Hemorrhagic CNS mets

Breast CA
Choriocarcinoma
Lung CA
Melanoma
RCC
Retinblastoma
Thyroid

Calcified CNS mets

Chondrosarcoma
Mucinous adenocarcinoma
Breast
Colon
Ovary
Stomach
Osteosarcoma

Calcified CNS primary tumors

Astrocytoma
Choroid plexus papilloma
Craniopharyngioma
Ependymoma
Gangliglioma
Meningioma
Neurocytoma
Oligodendroglioma
Pineal tumors
Any post radiotherapy.

Features of bleed from occult cavernoma

Edema only early on, resolves by 8 weeks
Resolving mass
Complete hemosiderin ring
No soft tissue component
Minimal enhancing centrally
Classic hemorrhagic progression on MRI
Decreases in size on f/u
about 1/5 calcify

Features of recently bled mass

Persistent edema on f/u
Persistent mass on f/u
Hemosiderin ring incmplete or absent
Soft tissue component
Nodular, ring, eccentric enhancement
MRI progression delayed
Increased in size on f/u instead of decreasing
Calcification rare.

Pleomorphic xanthoastrocytoma

Children and young adults (first three decades)
Preference for peripheral temporal lobes
Meningeal base in 2/3 cases
Often present with seizures (think to the location)
Homogeneous enhancing
Cysts in 1/3 to 1/2
Hemorrhage and calcification uncommon.
No cortical dysplasia
WHO grade II 80% at 5 years.
Similar to DNET on imaging.

Supratemtorial PNET formerly cerebral neuroblastomas

WHO grate IV
The younger at diagnosis, the worse.
Often cystic 1/2 to 2/3, hemorrhagic, pediatric
High recurrence and seeding rate
Usually large at diagnosis
Heterogeneous and heterogeneously enhancing on CT and MRI
Locations
Frontal
Parietal
Occipital
Not much edema
Well circumscribed

Medulloepithelioma

WHO grade IV
Occur in infants
More supratentorial, but can in infra
Locations
Temporal more than parietal, even in globe
With progression develop pretty much any appearance, cysts, calcification, necrosis, enhancement, eventually subarachnoid dissemination

Ependymoblastoma/PNET

WHO grade IV Death 6-12 months.
Neonates and young children.
Supratentorial as opposed to ependymoma
Large at diagnosis with enhancement, edema, peripheral necrosis, cysts
Still pretty well circumscribed.
Invade leptomeninges
Arise in periventricular neuroepithelium, so usually appose ventricles.

Ganglioglioma

Children and young adults (80%<30 years) F>M
Most common mixed glioneural tumor in CNS
Usually present with seizure
Benign, Slow, Bony remodeling
Locations
Temporal (up to 85%)
Frontal
Anterior 3rd ventricle
Cerebellum
Often cystic (more in younger pts), hypodense
1/3 calcify
Faint enhancement
MRI features vary depending on cyst composition
Worse prognosis with higher metabolism on PET, vasogenic edema, degree of glial differentiation

Gangliocytoma

No actual glial component, so no potential for malignancy unlike gangligliomas.
Very jellylike.
Location
Cerebral cortex or cerebellum (what's left)
Can be called Lhermite-Duclos if cerebellar
CT
Hyperdense
MRI
T1 iso, T2 iso, FLAIR hyperintense, basis for identification

Desmoplastic Infantile Ganglioma

Variant of ganglioglioma occuring infirst 2 years
Location
Frontal
Parietal
Meningeal base
Cysts are the rule with
Peripheral rim or nodular enhancement.
May have calcified rim
Looks like huge GBM in an infant, but has good prognosis WHO grade 1
MRI
T2 hypointense rim due to desmoplasia

Desembryonic neuroepithelial tumor DNET

WHO grade 1
Locations
Temporal 2/3
Frontal 1/3
Septum pellucidum.
Prepherally, cortex and subcortical WM almost always involved.
Neuroepithelial in origin
Looks like gangliglioma
Present second or therd decade with chronic seizures (again think to the location)
MRI
Multiple cysts
Very bright T2
Septations in triangular pattern
Enhancing (about 1/3)
CT
Hypodense
Usually no edema
Bony remodeling
Very slow grower.
50% association with cortical dysplasia of some type.
Resection curative
Recurrence is rare

Astrocytoma

Most frequent priomary solitary intraaxial mass in adult
Types
Circumscribed (WHO I)
pilocytic
pilocytic giant cell
PXA
Diffuse (WHO II) least likely to enhance. Most
common in brainstem
Fibrillary
gemistocytic exclusively in cerebral hemis.
(80% convert to GBM)
protoplasmic
Anaplastic (WHO III)
GBM (WHO IV)

Anaplastic astrocytoma

4th and 5th decades
evolve from lower grades
Ill defined borders
prolific vasogenic edema
Likely to enhance.
If there is necrosis, bump to GBM status.
Often predated by diffuse astrocytoma. Mean transformation to GBM is 2 years.

GBM

Majority in the ledrly are actually primary, not evolved from lower grades.
Death in few months WHO IV
Evolved GBMs less agressive, younger population
Most common of the astrocytomas.
Location
Frontal
Parietal
Temporal
Characterized by necrosis in the tumor.
Enhancing, hemorrhagic
High choline levels on MRS, the higher, the worse.

Syndromes associated with brain tumorw

Basal cell nevus syndrome
medulloblastomas
Cowden
cerebellar gangliocytoma
vHL
Li-fraumeni
Astrocytomas>PNET>Chroid plexus tumor
Mafucci
NF1
NF2
Ollier
Tuberous sclerosis
Turcot
Glioblastoma>>meduloblastoma

Temproal lobe neoplasms

Gangliglioma 0-30
Astrocytoma, low grade 0-30
DNET 10-20
Oligodendroglioma 30-60
PXA 10-35
Desmoplatic infantile gangliglioma 0-1

Gliosarcoma

GBM variant, about 2%, very nasty
Prefers supratentorial space.
Can be well defined, superficial and well enhancing

Multicentric astrocytoma

May be metachronous or contiguous spread
Associated with NF1

Corpus Callosum masses

Neplasm
GBM
Lymphoma
Mets

Demyelinating
MS
PML
Adrenoleukodystrophy
Marchiafava-Bignami disease
PRES

Acute shear injury
Stroke
Lipoma

Subependymal giant cell astrocytoma

Another glioma variant
Classically associated with tuberous sclerosis.
Age range 2-20
Location
near foramina of monro
Enhance (tubers do not)
Projects into the ventricle
MRI
A lot of subependymal things enhance that do not on CT, so CT may be better to look for this lesion.
WHO grade 1

Central neurocytoma

WHO grade II
Frequent calcification, cystic
Location: favors lateral or 3rd ventricle
Edema is rare
Peak in third decade.

Oligodendroglioma

WHO grade II
Looks very simila to central neurocytoma, but peak is 5th and 6th dacades. M>F
Has calcification, soft tissue and cystic component
Variable appearance depending of cellular composition ratio
Variable enhancement
MRI
Hypo T1, Hyper T2/FLAIR
CT
Hypo or isodense, again depending of cellular composition
NO edema

Anaplastic alogodendroglioma

Wrose than regular oligodendroglioma
Peak mean is 49
Location
Frontal
Temporal
Has everything, hemorrhage, necrosis, calcification, cystic, avid enhancing

Gliomatosis cerebri

At least two lobes are diffusely infiltrated with tumor.
Lack of mass effect or distortion.
Peak age 40-50
WHO Grade III
Bilateral in half of cases (half, get it?)
CT
Subtle. Maybe loss of G/W junction little mass effect
MRI
Better, but still subtle.
Diffuse subtle T2 hyperintensity
Minimal enhancing if at all
May degenerate to GBM with rapid growth
48% at 1 year, 27% at 2 years

Chordoid glioma

Location
Hypothalamus
Anterior third ventricle
WHO grade II
Slow growing, solid, well circumscribed, enhancing
CT
Hyperdense
MRI
Iso on T1 and T2
May have central necrosis
Age range over 30
Mass effect may cause hydrocephalus

Astroblastoma

Rare
Age: young edults
Well circumscribed, peripheraly enhancing, centrally necrosing. Usually large at diagnosis.
Complete resection curative

CNS lymphoma

Most commonly the diffuse hystiocytic type non-Hodgkins
Often associated with immunodeficiency of some type
Many appearances, mass, coating, malignant effusion
Can spread across corpus callosum
Usually abuts ependymal surface (toxo does not)
Can coat ventricles
NM
Thalium avid (good way to differentiate from Toxo, which is
not)
CT
Hyperdense with dense enhancement is classic, HOWEVER
in immunocompromised patient, can also be hypodense
MRI
Variable multiple lesions. Look for correct distribution
Heterogeneous on T2
Marked homogeneous enhancement
Bright on DWI due to high cellularity

Intravascular CNS lymphoma

Angiogtopic variant
Infarct-like lesions
Focal parenchymal enhancement and/or dural enhancement
Multifocal

CNS Sarcoma

Meningial types are most common (Meningo, fibro, etc.)
From there invade the brain.
Of primary parenchimal types, Gliosarcoma is most common
Acts like GBM and arcoma rolled into one.
Location
Favor temporal lobe with invasion of dural surfaces.

Germinoma

aka Seminoma
Most common pineal tumor of germ cell origin
M>>>F
Location
Pineal
Suprasellar
Age: Adolescents and young adults, rarely over 30
Symptoms: Most commonly Perinaud's syndrome
Precocious puberty if active
CT
Hyperdense mass
Marked enhancement
Engulfed pineal gland (Ca++ inside pineal inside tumor)
MRI
Iso T1, Slightly hypo T2
Responds well to radiotherapy.
CSF seeding is common
Can have cystic component (esp if in unusual location, in which case not as radiosensitive)

CNS teratoma

Looks about the same as elsewhere.
Second most common germ tumor in pineal region, and also like suprasellar cystern

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