Lesion/tumors Flashcards
Astrocytomas can be put in 2 catagories
Diffuse and circusmscribed
Circumscribed astrocytomas (2)
JPA (pilocitic). Subependymal giant cell tumor
Name the entity.
imaging characteristic, enhancement, syndrome)
Juvenile pilocytic astrocytoma
cerebellar cyst w/ a enhancing nodule. Will enhance even if low grade. Optic glioma in NF1
Name the entity
(where does it arise? Association? WHO classification
Subependymal giant cell astrocytoma
Large lobulated, vividly enhancing mass. Usually at foramen of monro. rises from lateral wall of ventricles.
a/w Tuberous sclerosis
WHO grade 1
Fibrillary astrocytoma - describe and name the 3 types
Infiltrative tumors that can occur anywhere in CNS. 3 types are Low grade (WHO2), anaplastic (WHO 3), and GBM (WHO4).
Low grade is a T2 bright thickened cortex, GBM is an irregular enhancing lesion.
Fibrillary astrocytoma - low grade type - imaging.
Hyperintense T2 w/ no enhancement. Thickened cortex
Fibrillary astrocytoma - Anaplastic type - imaging
WHO3 - between low grade and gliomatosis cerebri. From thickened cortex to irregularly enhancing mass.
GBM characteristics
WHO4 Heterogenous RIM enhancement, classic for crossing midline, can restrict, peritumoral spread leads to underestimation of size (spreads though white matter, CSF and subependymally)
Name the entity
parameters for diagnosis
Gliomatosis cerebri
WHO 2-3, Diffuse glioma with extensive infiltration, involves at least 2 lobes and extracortical involvement (basal ganglia, corpus callosum, brainstem, cerebellum. extensive T2 hyperintensity and little mass effect. May not enhance.
Things that cross midline (4) (2 tumors, a disease, and an iatrogenic thing)
GBM, Lymphoma, Tumofactive MS plaque, radiation
Tumors that classically restrict diffusion (3)
Lymphoma (homoenous), GBM (heterogenous), medulloblastoma
Name
Benign or malignant?
Choroid plexus xanthogranuloma.
Totally benign cyst. Restricts diffusion.
Lesion characteristics (enhancement, diffusion, nuc medicine finding (thallium or gallium?)
CNS lymphoma
Periventricular. Dense on CT. Homogenous enhancement, can cross midline, Restrict diffusion, thallium positive.
Usually B-cell lymphoma. “melts” away w/ chemo treatment.
immunocompromised patient: enhancing periventricular mass that crosses midline.
Immunocompetent: enhancement without central necrosis.
Ddx for diffuse T2 hyperintensity in brain (4)
Gliomatosis cerebri, PML, HIV encephalopathy, Lymphoma
Tumors that calcify (Old elephants age gracefully is a mneumonic that goes in order of frequency)
Oligodendroglioma, ependymoma, astrocytoma, GBM.
Classic tumor that calcifies
Oligodendroglioma
Tumor name
demographics
imaging
location
prognostic factor
oligodendroglioma
Young to middle aged patient with seizures
Calcifies, cortically based, expands cortex
likes frontal lobe
Important prognostic factor is 1p.19q deletion.
Ddx Cortical based tumors (DOG)
Dysembryoplastic neuroepithelial tumor (DNET), Oligodendroglioma, Ganglioma
Name the lesion
Demographics
Imaging
Dysembryoplastic neuroepithelial tumor (DNET)
Kid w/ refractory seizures.
Bubbly, cortical, T2 bright lesion in temporal lobe.
Name the lesion:
epidemiology, imaging, enhancement
Bimodal (1-5 years (in posterior fossa) or >40 years (in spine)), soft/plastic tumor (toothpaste), low cellularity, Avidly enhances. Calcium and hemorrhage in 50%, origniate from floor of 4V)
Name the lesion
(Official name, WHO grade, association, histologic composition)
Corduroy/tiger striped lesion in cerebellar hemisphere
Lhermitte-Duclos (AKA dysplastic cerebellar gangliocytoma). T1 hypointense/nonenhancing. T2 - Tiger stripes.
WHO1
a/w cowden syndrome
Part hamartoma, part neoplasm.
Embryonal tumors. What are they. 2 types
WHO grade 4 Primitive neuroendocrine tumors.
ATRT, medulloblastoma
Atypical teratoid/rhabdoid tumor
WHO4, aggressive, looks like medulloblastoma but occurs in younger patients and is more aggressive
Medulloblastoma (age, CT characteristics, MR (T2, ADC,enhancement), classic enhancement pattern. Location. Difference in location if it arises in adult.
75% < 10yo, spherical, highly cellular which means it is slightly higher density on CT, hyperintense on T2, low on ADC. homogenous calcium, arises from medullary velum (roof of 4V), but it may arise eccentrically in cerebellum in an adult.
Cyst w/ a nodule (4)
JPA, hemangioblastoma, Pleomorphic xanthoastrocytoma, ganglioma
Cyst w/ nodule - breakdown by location
JPA (kid) and hemangioblastoma (adult) are infratentorial, PXA and ganglioma is supratentorial
Hemangioblastoma (WHO1), syndromic association, where, appearance, when in spinal cord, what is it associated with.
VHL, cerebellum, medulla, or spinal cord. Cystic mass with mural nodule. Vascular. When in spinal cord, a/w syrinx
PXA vs. ganglioma imaging distinction
PXA has dural tail, ganglioma has no dural tail
PXA (WHO2) (pleomorphic xanthroastrocytoma), location, appearance. Demographics/clinical presentation. What is an identical entity, but seen only in infants?
Temporal lobe, invades leptomeninges. Dural tail. It occurs in childhood and adolescents, a/o epilipsy. In infant it would be called a Desmoplastic infantile ganglioglioma
Ganglioma imaging.
Cyst w/ nodule. Variable appearance, but nodule usually enhances. in temporal lobe. Presents in adolescent w/ seizures.
Intraventricular tumors (5)
Central neurocytoma, chroroid plexus papilloma/carcinoma, intraventricular meningioma, subependymal giant cyst astrocytoma (SEGA), subependymoma
Central Neurocytoma (epidemiolgy/prognosis, typical imaging)
Low grade, good prognosis. Lobulated mass attached to septum pellucidum w/ numerous intratumoral cystic areas. Frequently calcified.
Choroid plexus papilloma(WHO1)/Carcinoma (WHO3) - epidemiology, MRI imaging. Most common location in Children and adults.
Papilloma is most common brain tumor in babies <1year old. T2 intense/heterogenous, enhances. In children it occurs in atrium and lateral ventricle. In adults ints in 4th ventricle. Choroid plexus carcinoma is not distinguishable.
Intraventricular meningioma - where? Epidemiology?
Trigone. Older patients.
Subependymoma, epidemiology, location/imaging.
Benign (who 1), adult, often incidental. Inferior aspect of 4th ventricle. Nonenhancing. (Subependymoma is not related to ependymoma or SEGA. And its pretty benign and found incidentally, like a substitute)
Tumor that occurs supratentorially in kids, and infratentrially in adults (opposite of rule)
Choroid plexux papilloma/carcinoma. Pediatric = lateral trigone. In adult = 4th ventricle. High enhancing. Calcified, hydrocephalus.
CNS lymphoma (etiology, general apperance)
Large B cell lymphoma. Lymphoid from cerebral blood vessels (because brain does not have native lymphoid), Periventricular highly cellular mass. Further imaging details depend on immune status)
CNS lymphoma in immunocompetent patient
Enhancing periventricular mass (no necrosis). Can cross midline
CNS lymphoma in immunocompromised patient.
Periventricular ring-enhancing lesion in basal ganglia. Ring enhancement due to central necrosis.
How to differentiate CNS lymphoma and Toxoplasmosis (4)
Empirical anti-toxo therapy, thallium scanning (CNS lymphoma takes up thallium), PET (Lymphoma is fdg avid), Perfusion scanning (lymphoma is hyprvascular, toxo is hypovascular.
Secondary CNS lymphoma (imaging)
Tends to involve meninges. May cause leptomeningeal carcinomatosis or epidural cord compression.
Mets to brain (most common ones, appearance)
Most common ones are lung, breast, melanoma. They occur at grey-white junction and enhance.
Meningioma (epidemiology, syndromic association and iatrogenic etiology)
in adults, femal predominance. NF2 has multiple meningiomas. Radiation therapy may cause meningiomas
Meningioma imaging (location, CT, MR
Can be intraventricular or intraosseous. CT hyperattenuating, 25% will calcify. On MRI T1 iso to hypo, variable T2. broad based attachment to dura. Enhancing Dural tail, extensive white matter edema, hyperostosis.
4 most common dural mets? (3 brain mets + 1 more)
Breast, lymphoma, SCLC, melanoma.
Posterior fossa mass in child (5)
Medulloblastoma, JPA, Ependymoma, hemangioblastoma, AT/RT
Posterior fossa mass in an adult (4)
Mets, hemangioblastoma, astrocytoma, medulloblastoma (young adult, lateral location).
Epidermoid
Follow CSF, but also bright on flair and restricts diffusion.
Intravascular (angiocentric) lymphoma
the other lymphoma, presentw w/ stroke like symptoms, microhemorrhage and multifocal infarcts.
Pituitary apoplexy (imaging on T1. Causes. Classic clinical presentation)
T1 bright, cause by bromocriptine and “sheehan’s syndrome” (postpartum no w can’t lactate)
Ependymoma vs .medulloblastoma
Medulloblastoma is more spherical, highly cellular, and arises from medullary floor of velum (roof of 4V). Ependymoma is soft/plastic, has low cellularity, and arises from floor of the 4th V.
NF-1
Optic pathway pilocytic astrocytomas, antermedial tibial boweing, lateral meningocele, RAS, sphenoid dysplasia
NF-2 (miss me? MSME)
Multiple schwanomas, meningiomas, ependymomas (NO NEUROFIBROMAS W/ NF2)
Tuberous sclerosis
subependymal nodules (T1bright, T2 dark), cortical tubers (T2 bright bands), SEGA (can cause hydrocephalus), AMLs, LAM
VHL (3, 3, 3)
3 in pancreas: Serous Cystadenoma, regular cysts, islet cell tumors.
3 in rest of belly: Pheo, RCC (younger age/clear cell), Renal cysts.
3 in CNS. Hemangioblastoma in brain, hemangiomioblastoma in spine, Endolymphatic sac tumor.
males get epidydypal cysts
Cowden symdrome
Hamartoms, breast cancer, thyroid cancer.
Cowden Cold Syndrome
Cowden sydrome + lhermitte-duclos (enlarged cerebellar hemisphere w/ striated appearance)
Important CPA structures (3 nerves and a vessel)
CNs 5,7,8. AICA .Most CPA lesions are extra-axial.
Ddx for CPA (3 main ones) (one that goes into IAC, one that doesn’t, and one that restricts diffusion)
schannoma, Schwannoma, Epidermpoid.
Describe CPA Schwannoma (most common CPA mass)
Invades IAC, hyperintense T2 enhances. If bilateral, think NF-2. Its usually CN8 schannoma. Trigeminal nerve schwannoma may extend to meckels cave
Describe CPA meningioma
Doesn’t go into IAC, dural tail. Enhances homogenous, calcifies
CPA Epidermoid (congenital lesion from ectopic ectodermal epithelial tissue)
Follow CSF, but also bright on flair and restricts diffusion. Cauliflower like.
What is a “white epidermoid”
Rare epidermoid that is T1 bright.
Other CPA lesions
intra-axial neoplasm. Arachanoid cyst, aneurysm (PICA, AICA, basilar, vertebral. Look for flow void)
Possible CPA intra-axial neoplasms
Exophytic brainstem glioma, mets, medulloblastoma, ependymoma, hemangioblastoma, endolymphatic fat sac tumor.
What do anterior and posterior pitutiatries secrete?
anterior: ACTH, prolactin, TSH, FSH, LH. Posterior is from neuroectoderm and secretes vasopressin and oxytocin.
What is posterior pituitary bright spot?
T1 brightness of posterior pituitary.
Most sellar region masses are extrinsic to pituitary. Lesions that are intrinsic to pituitary include (just 2 main ones)
Adenoma, hypophysisits, rathke’s cleft cyst (sometimes). (cranyopharyngioma is usually outside the gland).
Pituitary Microadenoma, imaging/presentation.
less than 10mm, enhances less than normal gland. Will present with hormone changes
Pituitary macroadenoma. Imaging/presentation
More than 10mm. Will present with mass symptoms of vision changes.
Pituitary autoimmune inflammatory disorder in peripartum women. Name, clinical presentation, imaging treatment.
Lymphocytic hypophysisits. May affect pitutary and infundibulum. Presents w/ DI, visual impairment, headache, endocrine dysfunction. There is thickening and enhancement of pituitary stalk. Treated with steroids.
Granulomatous hypophysisitis
imaging is similar to lymphocytic hypohpysitis, but it is due to sarcoid, wegner, tb, or LCH.
SATCHMO
Sarcoid/suprasellar adenoma, aneurysm, teratoma/Tolosa Hunt. Craniopharyngioma/rCC, hypothalmic glioma (adults, Hypothalmic haratoma (children). Meningioma/mets. Optic nerve glioma.
Craniopharyngioma
Most common suprasellar tumor of childhood. Bimodal age presentation. Childhood type calcifies. In adults it is solid. Squamous epithelium. Usually separate from pituitary. MRI shows complex cystic mass that is hyperintense on T1 due to protein, blood, cholesterol. avid enhancement of solid dlements and cyst walls.
Major distintions of RC and craniopharyngioma
Craniopharyngioma is squamous, it is bimodal but more common in kids, it avidly enhances, and it is almost always distinct from pituitary.
Rathke’s cleft cyst
Remnant of rathke’s pouch,e precurson of anterior lobe of pituitary. Columnar/cuboidal cells. More common in adults/females. Does not enhance, may sometimes be inseperable from pituitary. T1 imagies varies depending on protein content.
Optic pathway glioma (astrocytoma)
T1 isoinense, T2 hyper, enhance. This is the 2nd most common suprasellar mass in kids (after craniopharyngioma). It is low grade if in children, but aggressive in adults.
Suprasellar Germinoma
80% are in pineal gland, but 20% are in parasellar region. Seen in childrend and adolescents. Homogenous, intensly enhanceing midline mass. Hypointense on T2, dark on ADC.
Complication of suprasellar dermoid cyst
Contains intracystic fat which can cause chemincal meingitis or ventriculitis with rupture.
Mass in hypothalmus (aunt minie), classic history
Hypothalmic hamartoma. Classic history is Gelastic seizures (laughing seizures) or precoucious puberty. Sessile mass between pituitary stalk and mamillary bodies. Does not enhance.
Pituitary apoplexy
T1 bright, cause by bromocriptine and “sheehan’s syndrome” (postpartum no w can’t lactate)
Most common met to parasellar region
breast cancer.
Ddx suprasellar mass in child (5)
Craniopharygioma, optic pathway glimoa, germ cell tumor (germinoma or dermoid), hypothalmic hamartoma, LCH hypophysitis.
Ddx suprasellar mass in adult (6)
macroadenoma extension, meningioma, craniopharyngioma, RCC, aneurysm, lymphocytic or granulomatous hypophysitis.
What structures surround the pineal gland?
in between thalami and posterior aspect of 3rd vent. Internal cerebral veins and vein of galen are superior and posterior respectivly.
Pineal gland cell and function
Pinealocyte. Releaces meltomin.
Complications of pineal mass lesion
midbrain compression, cerebral aqueduct, compression of tectal plate causing parinaud syndrome (upward gaze paralysis, pupillary light dissociation, nystagmus)
How to tell pineal lesion vs. tentorial meningioma
Pineal tumors lift internal cerebral veins. Tentorial meningiomas depress them.
Germinoma (extra-gonadal seminoma)
highly cellular, iso on T1 and T2, avidly enhances, dark on ADC. Slightly dense on CT. Engulphs pineal gland. Imaging of neuroaxis is recommended for leptomeningeal meds.
2 Germ cell tumors
Germinoma, teratoma.
Intrinsic Pineal masses (5)
Germ cell tumor, pineal cyst, pineocytoma, pineoblastoma, mets
pineal cyst
Most common pineal lesion. Differential includes pineocytoma, but this is much more rare.
Enhancing mass in pineal gland with cystic changes.
Pineocytoma. WHO 1 or 2.
Pineal lesion with peripheral calcificatino “exploded calcification”
Pineoblastoma. WHO4. Tumor of young children. Can present with obstructive hydrocephalus. Poorly defined pineal mass which may invade adjacent structures. Restricted diffusion due to high cellularity. Leptomeningeal mets may occur. Trilateral retinoblastoma is for pinoblastoma and bilateral retinoblastomas. Quadrilateral retinoblastoma if the Sella is also involved.
What is trilateral retinoblastoma and quadrilateral retinoblastoma
trilateral; bilateral retinoblastomas and also pineoblastoma (3 light sensing organs). If Sella is also involved, then its quadrilateral.
Extra-pineal masses (4)
Glioma, vein of galen aneurysm, meiningioma, quadrigeminal plate lipoma
association with quadrigeminal plate lipoma
agenesis of hypoplasia of corpus callosum.
The name “vein of galen “aneurysm” is really a what?
dilatation of vein of galen due to av fistula b/w anterior or posterior circulation and the venous plexus leading to the vein of Galen.
