Rev. Bras. Reumatol. vol.55 número4

r e v b r a s r e u m a t o l . 2015;55(4):381–383

w w w . r e u m a t o l o g i a . c o m . b r

REVISTA

BRASILEIRA

DE

REUMATOLOGIA

Case

report

Lipoma

arborescens

of

the

knee

in

a

patient

with

ankylosing

spondylitis:

case

report

and

literature

review

夽

Elisa

Fernandes

de

Melo

,

Lina

Maria

Saldarriaga

Rivera

,

Luis

Alberto

Delgado

Quiroz

_,

_Blanca

_Elena

_Rios

_Gomes

_Bica

a_{DepartmentofRheumatology,HospitalUniversitárioClementinoFragaFilho,UniversidadeFederaldoRiodeJaneiro,RiodeJaneiro,}

RJ,Brazil

b_{MedicalSchool,UniversidadeFederaldoRiodeJaneiro,RiodeJaneiro,RJ,Brazil}

a

r

t

i

c

l

e

i

n

f

o

Articlehistory:

Received15February2013 Accepted5June2013

Availableonline28November2014

Keywords:

Lipomaarborescens Ankylosingspondylitis Monoarthritis

a

b

s

t

r

a

c

t

Lipomaarborescens(LA)isdefinedasa villouslipomatousproliferationofthesynovial membranewithdiffusesubstitutionofthesynovialtissuebymaturefatcells.Theinjuryis veryrare,involvingthekneejoint(suprapatellarregion)andisassociatedwithdegenerative jointdisease.Wedescribethecaseofamalepatient,sufferingfromankylosingspondylitis withmonoarthritisoftherightkneeandswellinginsuprapatellarregionimportant.The diagnosisoflipomaarborescenswasconfirmedfromtheMRIoftherightknee.

©2014ElsevierEditoraLtda.Allrightsreserved.

Lipoma

arborescens

de

joelho

em

paciente

com

espondilite

anquilosante:

relato

de

caso

e

revisão

da

literatura

Palavras-chave:

Lipomaarborescens Espondiliteanquilosante Monoartrite

r

e

s

u

m

o

Lipomaarborescens(LA)édefinidocomoumaproliferac¸ãovilosalipomatosadamembrana sinovialcomsubstituic¸ãodifusadotecidosinovialporcélulasgordurosasmaduras.Alesão émuitorara,envolveaarticulac¸ãodojoelho(regiãosuprapatelar)eseassociaadoenc¸as articularesdegenerativas.Descrevemosocasodeumpacientedesexomasculino,portador deespondiliteanquilosantecomquadrodemonoartritedejoelhodireitoeaumentode vol-umeimportantenaregiãosuprapatelar.Odiagnósticodelipomaarborescensfoiconfirmado apartirdaressonânciamagnéticadojoelhodireito.

©2014ElsevierEditoraLtda.Todososdireitosreservados.

夽

StudyconductedatHospitalUniversitárioClementinoFragaFilho,MedicalSchool,UniversidadeFederaldoRiodeJaneiro,Riode Janeiro,RJ,Brazil.

∗ _{Correspondingauthors.}

E-mailaddresses:[email protected](E.F.deMelo),[email protected](B.E.R.G.Bica).

http://dx.doi.org/10.1016/j.rbre.2013.06.004

382

Introduction

Lipoma arborescens (LA) is defined as a villous lipoma-tous proliferationofthesynovial membranewithadiffuse substitution of synovial tissue by mature fatty cells.1 _The lesion isvery rare andmore oftenfoundin males, involv-ingthekneejoint(suprapatellarregion)asamonoarticular, slowly-developing,andbarelypainlesscondition.Ithasbeen described in other joints,such as the hip, shoulder, wrist, ankle,andelbow.2

The condition etiology is unclear. It is associated with degenerativejoint diseases,but whetherthe joint degener-ation iscause or consequenceofthe pathological synovial hyperplasiaisnotknown.3

Patients present a progressive and longstanding effu-sioninthe involved joint,withpain andreduced range of movementbeingpotentialfindings.Examinationoftheknee revealsaboggy,supra-patellarswelling.Osteoarthritis(OA), diabetes mellitus (DM) and a history of local trauma can coexist.4

Laboratorytestresults,includingESR,rheumatoidfactor, anduricacid,areinvariablynormal.Synovialfluidobtained byarthrocentesisdevoidcrystals.5

Plain radiographs can show suprapatellar soft tissue swellingandarehelpfultoruleoutothercausesofpainand swelling.ThelesiononMRIischaracteristic:appearanceof anintra-articularsynovialmasswithahighsignalintensity frond-likesynovialproliferation.6

It is histologically characterized by a proliferation of the synovial villous lipomatous layer and subsynovial fat hyperplasia.7_{LAdiagnosisusedtobehistologicalmostofthe} time,butMRIiscurrentlyenoughtoestablishthediagnosis.8 LAshouldbeconsidered inthe differential diagnosis of conditionswithkneepain.9

Case

report

Amalewhitepatient aged55,borninRiodeJaneiro, diag-nosed with ankylosingspondylitis since2002, developed a monoarthritisoftherightknee. Thearthritisstartedabout oneyearearlier,buthethoughtthatwasatypicalcomponent ofhisdiseaseandthereforenohelpwassought.

On physical examination, the patient had an impor-tant swelling not only in the right knee, but also in the soft tissue of the suprapatellar region, with normal joint motionrange.Laboratorydatademonstratedaworseningin inflammatoryactivity tests notcorrelated with his inflam-matory condition that was in remission according to the historytaken,physicalexamination,aswellasimaging stud-ies.

Synovial fluid analysis for crystals, bacteria, fungi, and mycobacteria, inaddition toculturestorule out other dif-ferential diagnoses of knee monoarthritis, was negative. Imagingstudybymagneticresonanceimaging(MRI) ofthe rightkneeshowedalesionsuggestiveoflipomaarborescens (Fig.1).

Delayindiagnosiscausedanenlargementofthemass,with synovectomybeingindicated,adecisionmadeinconjunction withthedepartmentoforthopedics.

Fig.1–Axialmagneticresonanceoftherightkneeshows thearborescentlesion.

Discussion

Lipoma arborescens is a rare benign intra-articular lesion of unknown etiology in which a diffuse substitution of synovial tissue by mature fatty cells is associated with degenerative conditions, such as osteoarthritis or joint trauma, diabetes mellitus, and, in 20% of cases, popliteal cysts.10

Patientswithlipomaarborescensusuallyhave longstand-ing symptoms, suchasprogressiveswelling,joint effusion, pain,andreducedrangeofmovement.

The differential diagnosis of suprapatellar swelling includespigmentedvillonodularsynovitis,xanthoma, chon-dromatosis, rheumatoid arthritis, synovial hemangioma, amyloidarthropathy, lipomaarborescens. Computed tomo-graphy(CT)orMRIarehelpfulindifferentiatingitfromother conditions.11

Treatment is performed by intra-articular injections of radioactive compounds, such as Yttrium 90 or steroids, which alleviate symptoms for short to moderate periods of time. Surgicalmanagement is usuallyrecommended by an open or arthroscopic approach and includes a total synovectomy.12

Ankylosing spondylitis is a chronic, progressive, and inflammatorydiseaseprimarilyinvolvingsacroiliacjointsand theaxialskeleton(spine),withperipheraljointsbeingless fre-quentlyaffected.Itsonsetusuallyrangesfromthesecondto thirddecades,predominatinginCaucasianHLA-B27-positive males.13

Ofnoteinthecasereportedistheconcomitantoccurrence oflipomaarborescensandankylosingspondylitis.Todate,the rareassociationoftheseconditionshasneverbeendescribed intheliterature.

Conflicts

of

interest

r e v b r a s r e u m a t o l . 2015;55(4):381–383

383

r

e

f

e

r

e

n

c

e

s

1. HallelT,LewS,BansalM.Villouslipomatousproliferationof

thesinovialmembrane(lipomaarborescens).JBoneJoint

SurgAm.1998;70:264–70.

2. VilanovaJC,BarceloJ,VillalonM,AldomaJ,DelgadoE,

ZapaterI.MRImagingoflipomaarborescensandthe

associatedlesions.SkeletalRadiol.2003;32:504–9.

3. MartínS,HernándezL,RomeroJ,LafuenteJ,PozaAI,RuizP,

etal.Diagnosticimagingoflipomaarborescens.Skeletal

Radiol.1998;27:325–9.

4. BejiaI,YounesM,MoussaA,SaidM,TouziM,BergaouiN.

Lipomaarborescensaffectingmultiplejoints.SkeletalRadiol.

2005;34:536–8.

5. DawsonJS,DowlingF,PrestonBJ,NeumannL.Casereport:

lipomaarborescensofthesub-deltoidbursa.BrJRadiol.

1995;68:197–9.

6. MinkJH,ReicherM,CruesJ,DeutschA.Magneticresonance

imagingoftheknee.2ed.NewYork:RavenPress;1993.p.

344–53.

7.RodriguesCF,DosSantosE.LipomaArborescensdeJoelhos.

RevBrasReumatol.2008;48:192–4.

8.SivaC,BrasingtonR,TottyW,SoteloA,AtkinsonJ.Synovial

lipomatosis(lipomaarborescens)affectingmultiplejointsin

apatientwithcongenitalshortbowelsyndrome.JRheumatol.

2002;29:1088–92.

9.GolderosMA,PastorC.Lipomaintraarticularcon

presentaciónclínicademeniscopatia.Rehabilitación(Madr).

2011;45:71–4.

10.LiddleA,SpicerDDM,SomashekarN.ThonseChirag.Lipoma

ArborescensofbothKnees.JOrthopCaseRep.2012;2:

3–7.

11.KloenP,KeelSB,ChandlerHP,GeigerRH,ZarinsB,Rosenberg

AE.Lipomaarborescensoftheknee.JBoneJointSurg.

1998;80:298–301.

12.DaviesAP,BlewittN.Lipomaarborescensoftheknee.The

Knee.2005;12:394–6.

13.VieiraRMRA,EliasJR,BarbosaMHN,VoltarelliJC.Espondilite

anquilosante:investigac¸ãofamiliardeaspectosclínicos,

imunogenéticoseradiológicos.RevBrasReumatol.