Fat Containing Masses of Brain FILEminimizer

8/19/2019 Fat Containing Masses of Brain FILEminimizer

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Fat and Cholesterol

Containing Intracranial

Lesions

Pat Farley, MD

Neuroradiology Division, UNC


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Objectives

• o na!e "at containing lesions o" the

brain#

•$ive di""erentiators o" these lesions#

• %ecogni&e associations and co!'lications

o" these lesions#

• %ecogni&e that der!oid and e'ider!oiddo not loo( ali(e, just sound ali(e#


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Der!oid Cyst

• Unilocular cyst )ith thic( )alls o" connective

tissue

•%are * +#- . o" intracranial tu!ors

• Clinical Issues

* Unco!'licated Der!oids/• 0eadache 12.3

• 4ei&ure 12.3


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Der!oids, Co!'lications

• %u'ture * his can cause a che!ical !eningitis as the "at

dro'lets s'read )ithin the subarachnoid s'ace )ithresultant in"la!!atory changes#

* Larger lesions are associated )ith higher ris( o"ru'ture#

• rans"or!ation * %arely can trans"or! in to a !alignant s5ua!ous cell

cancer#

• Der!al sinus * Can lead to in"ection#


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Der!oids, I!aging 6''earance

• 7ell8circu!scribed li'id containing !asses

• Location * Most o"ten in sellar9'arasellar9"rontonasal region

* Posterior "ossa: !idline ver!is ;


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Der!oids, C 6''earance

• Non Contrast C * Classic

• %ound9lobulated, )ell8delineated, cystic !ass

• Fat hy'odensity

• >. contain ca'sular calci"ications• %u'ture, dro'lets o" "at disse!inate in cisterns, !ay cause "at8"luid

level )ithin ventricles

* 6ty'ical• ?dense? der!oid/ 0y'er attenuating on C

• 4(ull9scal' der!oid e@'ands di'loic s'ace• Frontonasal 8 Ai"id crista galli, large "ora!en cecu! )ith

'ossible sinus tract

• Post Contrast 8 No enhance!ent


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Der!oids, M%I

• B and >/ * 0y'erintense !ass on B7I# 0eterogeneous

signal on >#

* Che!ical shi"t arti"act in "re5uency encodingdirection

* %u'tured Der!oid• Dro'lets very hy'erintense on B7I

* Fat su''ression se5uence con"ir!s

* Fat8"luid level in cyst, ventricles co!!on

* ?dense? der!oid also hy'erintense on B7I


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Der!oid 1large arro), le"t3 and "at dro'lets in 4641arro)s, right3 are clearly seen#


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Der!oids, M%I )ith Contrast

• Unru'tured * No enhance!ent

• %u'tured * Can have intense !eningeal enhance!ent

secondary to che!ical !eningitis#

• M% 4'ectrosco'y * 4trong and broad resonances "ro! !obile

li'ids at # and B#2 ''!


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Der!oids, 6ngiogra'hy9M%6

• =asos'as! !ay be 'resent )ith ru'ture

• =essels encased by der!oid have anincreased ris( o" ru'ture#


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Der!oids, Prognosis9hera'y

• Co!'lete !icrosurgical e@cision * %esidual ca'sule !ay lead to recurrence * %arely surgical re!nants !ay degenerate in to

s5ua!ous cell cancer

• 4ubarachnoid disse!ination o" contents !ayoccur during o'erative9'osto'erative course * Cause ase'tic !eningitis or other co!'lications

1hydroce'halus, sei&ures, CN de"icits3

* Disse!inated "at 'articles can re!ain silent )ithoutneurologic changes


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Der!oid vs# 'ider!oid

• 'ider!oid E congenital inclusion cyst• Usual a''earance is si!ilar to C4F

* 6''earance is not identical to C4F ho)ever

• FL6I% usually does not co!'letely su''ress

• B9> !ay be slightly o"", CI449FI46 sho) internal structures• Di""usion restriction is (ey

• Can see internal structures on CI44 i!aging

• Mass interdigitates in cisterns, and encases nerves

and vessels#• Most co!!on di""erential "or e'ider!oid is

arachnoid cyst#


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'ider!oid in le"t CP6 cistern is si!ilar to C4F but

not e@actly li(e it# Note internal structures#


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D7I sho)s high signal

"ro! this e'ider!oid in the

le"t CP6 cistern#


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'ider!oid that could be con"used

)ith Der!oid

• %are variant

* Unco!!only hy'erintense to brain 1?)hitee'ider!oid?3 due to high triglycerides ;

unsaturated "atty acids


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'ider!oid vs# 6rachnoid Cyst

• Di""usion is (ey

• 'ider!oid is restricted

• 6rachnoid cyst is not

• 6lso e'ider!oids insinuate into adjacent

tissues, arachnoid cysts tend to dis'lace

the!#


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Le"t !iddle cranial "ossa arachnoid cyst sho)s no

enhance!ent and no restricted di""usion on 6DC !a' 1right3#


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Cranio'haryngio!a

• Aenign e'ithelial tu!or derived "ro!

%ath(es 'ouch e'itheliu!

• )o y'es/

* 6da!antino!atous ty'e 1classic3

• hy'erintense cyst and heterogeneous nodule

• More co!!on in children 1"irst age 'ea(3

* Pa'illary ty'e 1!ore rare3• isointense solid co!'onent

• More co!!on in adults 1second age 'ea(3


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I!aging o" 6da!antino!atous

Cranio'haryngio!a

• C/ Partially calci"ied, 'artially solid, cystic

su'rasellar !ass

• M% /

* B )ithout $d

• 0igh signal intensity su'rasellar !ass on 're8

contrast B7I 1'rotein, cholesterol, blood 'roducts

in "luid3

* B )ith $d/

• 4olid 'ortions enhance heterogeneously, cyst )alls

enhance strongly#


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Nearly cystic cranio'haryngio!a in the su'rasellar s'ace#


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Cranio'haryngio!a, Locations

• %elation to 4ella * 4u'rasellar 1G-.3

* 4u'rasellar and intrasellar co!'onents 1>B.3

* ntirely intrasellar 12.3, 'osterior and9orretroclival 1>.3

• %are locations / * O'tic chias!, 2rd ventricle

* Naso'haryn@, 'ineal gland, s'henoid 1sinus, clivus3


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Cranio'haryngio!a, Other

I!aging 6''earances• =ariable si&e

*o"ten large at 'resentation 1H - c!3

• ""ect on surrounding brain

* 0y'erintense signal in brain 'arenchy!a

adjacent to tu!or

• $liosis, tu!or invasion, irritation "ro! lea(ing cyst

"luid

• de!a "ro! co!'ression o" o'tic chias!9tracts


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erato!a

• Midline !ass

* calciu!, so"t tissue, cysts, and "at

• Locations/

* Midline "ro! o'tic chias! to 'ineal gland

* 4u'ratentorial !ost co!!only


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erato!a, C

• C )ithout contrast

* 0y'er, iso8 and hy'o8dense co!'onents o"

"at, "luid, so"t tissue, and calci"ication

• Post Contrast

* 4o"t tissue co!'onents enhance


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erato!a, M%I

• B7I

* 0y'erintense signal "ro! "at

* =ariable signal "ro! calciu!

• M% hel's characteri&es relationshi' o"

terato!a to !idline structures


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)o e@a!'les o" !ature 2rd

ventricular and su'rasellarterato!as sho) cysts, solid co!'onents, and "at on non

contrast studies#


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erato!a, Prognosis

• De'ends on si&e and location

• Aenign vs# Malignant

* - year survival "or !alignant terato!as is

B.


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erato!a, =ariant

• 0olocranial

erato!a in

ne)borns

• Ae sus'icious o" it in

a ne)born )ith an

intracranial !ass

re'lacing nearly allnor!al brain tissue#


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Li'o!as

• Mass !ade u' o" !ature non8neo'lastic

adi'ose tissue

• Congenital !al"or!ations, not true

neo'las!

• 6rise "ro! !al"or!ation o" cells in

'ri!itive subarachnoid s'ace 1!enin@

'ri!itiva3


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Li'o!as, Location

• Midline location co!!on * 4u'ratentorial .

•


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Li'o!as, I!aging

• C * 8- to 8B 0 1"at density3

* Calci"ication varies "ro! none to e@tensive

• M%I * 0y'erintense on B7I

* 0y'ointense )ith "at su''ression

* 4tri(ing che!ical shi"t arti"act on >7I• nhance!ent

* None


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)o e@a!'les o" 'ericallosal li'o!as# Le"t/ nodular ty'e )ithcallosal agenesis# %ight/ tubular )ith nor!al cor'us callosu!#


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Li'o!as, =ascular I!aging

• Angiographic Findings

• Conventional

* 6C6 courses directly su'eriorly i" CC agenesis

'resent * 6rteries ; veins o"ten e!bedded )ithin li'o!a

• 4i!ilar "indings !ay also be seen )ith

M%6


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Li'o!as, Mor'hology

Interhemispheric lipomas

* Curvilinear ty'e

• hin, curves around CC body, s'leniu!

* ubulonodular ty'e

• Aul(y !ass "re5uent calci"ication, usually

associated )ith cor'us callosal dysgenesis


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Neo'las!s )ith Fat

• Lipomatous differentiation/transformation of

neoplasm

* Neuroectoder!al tu!ors

• PNs, e'endy!o!a, glio!as is rare * Cerebellar li'oneurocyto!a

• Mi@ed !esenchy!al9neuroectoder!al 'osterior "ossa

neo'las!

• Pri!arily hy'ointense on B7I, !i@ed )ith hy'erintense "oci

)ith 'atchy, irregular enhance!ent

* Meningio!a

• li'o!atous trans"or!ation is unco!!on


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Li'o!atous rans"or!ation o"

Meningio!a

• Mature adi'ocytes "ro! !eta'lasia and!eningio!a or "ro! 'roduction o" triglyceridesby cells

• %are variant o" !eningio!a• C * 0eterogeneous )ith heterogeneous enhance!ent

* Can !i!ic necrotic !alignant tu!ors

* De!onstration o" "at attenuation suggests a benign'rocess but di""erential diagnosis o" an e@tra8a@ial "at8containing tu!or should include li'o!atous!eningio!a#


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4u!!ary

Der!oid * 0y'erintense on B can be heterogeneous on ># No

enhance!ent#

• Li'o!a

* 0y'erintense on B, no enhance!ent, can have calci"ications,loo( "or CC dysgenesis

• Cranio'haryngio!a

* Contains hy'erintense B cholesterol9blood 'roducts, so"t tissue,

cystic structures and calci"ication, enhances

• erato!a

* Contains hy'erintense B "at, so"t tissue, cystic structures and

calci"ication, enhances

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Fat Containing Masses of Brain FILEminimizer