c o m Nathan Andersona,b,∗, Claudia DiBellaa,b,c, Marcus Piantad, John Slavine, Peter Choonga,b,c a Department of Orthopaedics, St Vincent’s Hospital Melbourne, 41 Victoria Parade, Fitzr
Trang 1CASE REPORT – OPEN ACCESS
Contents lists available atScienceDirect
j o u r n a l h o m e p a g e :w w w c a s e r e p o r t s c o m
Nathan Andersona,b,∗, Claudia DiBellaa,b,c, Marcus Piantad, John Slavine,
Peter Choonga,b,c
a Department of Orthopaedics, St Vincent’s Hospital Melbourne, 41 Victoria Parade, Fitzroy, Victoria 3065 Australia
b Bone and Soft Tissue Sarcoma Service, Peter MacCallum Cancer Institute, Melbourne, Victoria 3002, Australia
c Department of Surgery, The University of Melbourne, Parkville, Victoria 3002, Australia
d Department of Radiology, St Vincent’s Hospital Melbourne, 41 Victoria Parade, Fitzroy, Victoria 3065, Australia
e Department of Pathology, St Vincent’s Hospital Melbourne, 41 Victoria Parade, Fitzroy, Victoria 3065, Australia
a r t i c l e i n f o
Article history:
Received 24 January 2015
Received in revised form 10 May 2015
Accepted 11 May 2015
Available online 14 May 2015
Keywords:
Aneurysmal bone cyst
Fibrous dysplasia
a b s t r a c t
INTRODUCTION:Aneurysmalbonecystoccurringinthesettingofpreviouslydiagnosedfibrousdysplasia
israre.Whilebotharebenignprocesses,pain,compressionofnearbystructuresandriskoffracturecan requiretreatment
PRESENTATIONOFCASE:Inthisreport,wedescribea56yearoldmalewhodevelopedanaggressive aneurysmalbonecystsecondarytofibrousdysplasiaintheproximaltibiaoveraperiodof8months
Herequiredanabovekneeamputationfordiseaseandsymptomcontrolduetotheaggressivenatureof diseaseandmedicalcomorbidities
DISCUSSION:Thediagnosisofasecondarylesioncanprovedifficult.Itisimportanttoexcludeamalignant diseaseprocess,particularlywhenimagingdemonstratesanaggressiveappearance.Inthiscase,repeat imaging,CTguidedbiopsiesandanopenbiopsywereperformedtoexcludemalignancypriortodefinitive surgicalmanagement
CONCLUSION:Inordertoexcludesecondarylesions,wesuggestfurtherinvestigationfornewonsetpain
inthesettingofabenignlesion
©2015TheAuthors.PublishedbyElsevierLtd.onbehalfofSurgicalAssociatesLtd.Thisisanopen accessarticleundertheCCBY-NC-NDlicense(http://creativecommons.org/licenses/by-nc-nd/4.0/)
Fibrous dysplasiais a benign process where normal bone is
replacedwithfibrous tissue.It represents2.5%ofprimary bone
tumoursand occurspredominantlyinthefirst3decadesoflife
[1].Thegenemutationatthe␣-subunitoftheG-proteinreceptor
resultsinanincreaseofcAMP[2,3],causinghyperproliferationof
abnormalosteoblastsaswellasstimulatingcytokinepathwaysthat
leadtoincreasedboneresorptionbyosteoclasts.Acombinationof
thesetwo pathwaysproducethecharacteristiclesion.It usually
affectsthelongbones,craniofacialbonesandribs,andcanoccur
asasinglelesion(monostotic,70%),multiplelesions(polyostotic,
30%),oraspartofMcCune–Albrightsyndromeinvolving
polyos-toticfibrousdysplasia,café-au-laitspotsandmultipleendocrine
dysfunction[3,4,5].Radiologically,theappearanceoffibrous
dys-plasiaincludesendostealscallopingof theinner cortexwithout
periostealreaction,bonyexpansionandaground-glassappearance
∗ Corresponding author Tel.: +61 438 229 045; fax: +61 03 9288 2644.
E-mail addresses: nathananderson9@gmail.com (N Anderson),
resultingfromtheradiolucentboneproducingnovisible trabecu-larpattern.Thereisaclassichistologicalappearancewithalow
tomoderatecellularfibrousstromasurroundingirregular trabec-ulaeofwovenbone,arranged ina “Chinesecharacters”pattern [4,6,7].Inmildcases,treatmentconsistsofsurveillanceand mainte-nanceofbonedensitythroughdiet,exercise,andbisphosphonates [2,3].Inseverecases,surgicalreinforcementorcorrectionmaybe requiredwithinternalorexternalfixation,sometimeswiththeuse
ofcorticalallografts[2] Aneurysmalbonecystsappearasablood-filledcavityseparated
byconnectivetissueseptawithfibroblastsandosteoclast-likegiant cells.Theyexpandtheaffectedbone,usuallyoccurringatthe meta-physisoflongbones,flatbonesorspinalcolumn[7,8].Aneurysmal bone cystsare benign, but canbe locally aggressiveand cause weakeningofthebonystructure,andexpansioncancausepain, swelling,deformity,neurologicalsymptomsandpathological frac-ture[9,10].Radiologically,theyappearasaneccentricexpansile lesion;CTandMRIcanshowinternalseparationsandfluidlevels [8].Whilepathogenesisisnotcompletelyunderstood,the develop-mentofaneurysmalbonecystshasbeenlinkedtotumour-induced vascularprocessesorasaconsequenceoftrauma[6],andcanoccur
asasecondaryvascularphenomenoninareasofapreviouslesion [11]
http://dx.doi.org/10.1016/j.ijscr.2015.05.019
2210-2612/© 2015 The Authors Published by Elsevier Ltd on behalf of Surgical Associates Ltd This is an open access article under the CC BY-NC-ND
Trang 2Fig 1. Initial presentation of right tibial diaphyseal lesion:
Radiolucent lesion with medullary expansion and endosteal scalloping shown in: (A) AP radiograph; (B) Coronal CT scan showing a well circumscribed lesion with endosteal scalloping; (C) Coronal T1 with fat saturation MRI; (D) Thallium scan showing moderate heterogeneous uptake in the right proximal tibia on delayed 4 h planar imaging; (E) Core biopsy showing spindle cell proliferation (red arrow) and fibrous stroma with immature bone formation (green arrow), consistent with fibrous dysplasia.
A56yearoldmalepresentedwithrightproximaltibialpain
Hehadswellingandlocalizedtendernessinhisproximalleg,and
requiredcrutchesduetopain;hehadnoskinpigmentationsor
neurovascularcompromise.Twomonthspriortohispresentation,
a drug eluting stent had been inserted for treatment of
coro-naryarterydisease.Hehadbeencommencedonclopidogreland
aspirin
Imagingwas consistentwithfibrous dysplasia in the
proxi-maltibia;thelesionmeasured15cminlengthanddemonstrated
endostealscalloping,ground-glassopacityandmedullary
expan-sion without periosteal reaction (Fig 1) A skeletal survey
performedpriortoreferraltoourhospitalrevealedmultiple
radi-olucentlesionsthroughoutbothfemoralandrighttibialdiaphysis,
consistentwithpolyostoticfibrousdysplasia.Thalliumscan,which
highlightsmetabolicactivity[6,12],showedheterogeneousmild
uptakewithinthetibiallesionandnouptakeinotherlesions.Core
biopsywasperformed underCT guidancetargeting theareaof
thalliumavidity,andpathologyshowedspindlecellproliferation
andfibrousstromawithimmatureboneformation(Fig.1).There
werenofeaturesofmalignancyandthelesionwasplacedunder
surveillanceafterthediagnosisoffibrousdysplasiawasmade
Fivemonthslater,here-presentedwithincreasedpaininthe rightleg.Plain radiographsshowedcorticalthinningassociated with a pathological fracture of the anterior cortex of the tibia andanincreaseinlesionsize(Fig.2).CTshowedcorticalbreach andperiostealreaction.Therewasconcernofmalignantchange withMRIfeaturesofheterogeneousT2hyperintensityaswellas medullarysofttissueexpansion.Fluid-fluidlevelswerealsonoted (Fig.2).A CT guided corebiopsy was performed targeting the areaof uptake onarepeat thalliumscan Thisshoweda cellu-larlesionwithnumerousmulitnucleatedgiantcellstogetherwith smallermononuclearcells,haemorrhage,fibrinandgranulation tis-sue(Fig.2).Thesefeatures weresuggestiveofsolidaneurysmal bonecyst,however,anopenbiopsywasperformedduetoclinical concernofmalignancy.Intra-operativelyitwasnotedthatthere wasextensivethinningofthebonycortexandreplacementofthe bonyarchitecturewithhaematoma.Curettagewasperformedand analysed,andshowedasimilarlesiontothepreviousbiopsy.This wasconsistentwithsolidaneurysmalbonecyst
Duetotheanticoagulantspreventingdefinitivesurgical inter-vention, angiographic embolisation was attempted but was unsuccessful[13].Thepatientwasthereforetemporarilyplaced intoabi-valvedthermoplasticsplintandcommencedonzoledronic acidinanattempttocontrolthegrowthofthelesion[3,14,15].His
Trang 3CASE REPORT – OPEN ACCESS
54 N Anderson et al / International Journal of Surgery Case Reports 12 (2015) 52–56
Fig 2.Presentation at 5 month mark:
(A, B) AP and lateral plain radiographs showing cortical erosion, soft tissue extension and minimally displaced pathological fracture (arrow); (C) Coronal STIR weighted MR image showing cortical destruction and medullary soft tissue expansion with associated internal fluid-fluid level (arrow); (D) Thallium scan demonstrates peripheral thallium avidity within the proximal right tibia; (E) Open biopsy showing mulitnucleated giant cells (red arrow) together with smaller mononuclear cells, haemorrhage, fibrin and granulation tissue Also an area of fibrous stroma is seen (green arrow) These features are consistent with aneurysmal bone cyst in the setting of fibrous dysplasia.
symptomswerecontrolledwiththistherapyandhewasableto
mobilisewithcrutches
Overatime-periodof3monthshedevelopedincreasingpain
requiringadmissionandthiswasunabletobecontrolleddespite
maximalanalgesia.Repeatimagingshowedextensivedisease
pro-gressionwithincreasedlesionsize,corticaldestruction,softtissue
extensionintoallcompartmentsofthelegandencapsulationofthe
neurovascularbundle(Fig.3).Itwaselectedtoperformanabove
kneeamputationforlocalcontrolasitwasfeltalimbsalvage
proce-durewasnotpossible.Histologyonthewholespecimenconfirmed
extensiveaneurysmalbonecystinassociationwithfibrous
dyspla-siaextendingintosofttissue,againwithnofeaturesofmalignancy
(Fig.3)
Aneurysmalbone cystoccurringin thesetting of previously
diagnosedfibrousdysplasiaisararepresentation.Wedescribea
patientwithknownpolyostoticfibrousdysplasiawhodeveloped
anaggressivesecondary aneurysmalbonecystthatpresented a diagnosticandmanagement dilemma.Sarcomawasincludedin thelistofdifferentialdiagnosesduetothedevelopmentofnew symptoms,aggressiveradiologicalappearanceand rapidrateof change.It hasbeenwelldocumentedthatfibrousdysplasiacan undergo malignant transformation;osteosarcoma, fibrosarcoma andmalignantfibroushistiocytomaarethemostcommonly diag-nosed [2,16,17].Ruggieri et al [17] reported 28 sarcomas in a reviewof1122histologicallydiagnosedcasesoffibrousdysplasia, andtherateofmalignanttransformationwashigherforpolyostotic diseasethanformonostoticdisease(6.7%versus1.9%).Suspicion for malignant changein a patient with known fibrous dyspla-siaisraisedwhenthereis increasedpainorradiologicchanges seenonroutinefollow-up[17],andthisshouldpromptre-staging; however,thesechangescanalsobecausedbypathological frac-tureorothersecondarybenignlesionssuchasaneurysmalbone cyst
Trang 4Fig 3. Presentation at 8 month mark:
(A, B) AP and lateral plain radiographs showing large radiolucent lesion with cortical erosion and soft tissue extension; (C) Coronal STIR weighted MR image demonstrates marrow replacement by soft tissue lesion with soft tissue extension; (D) Thallium scan demonstrates peripheral thallium avidity of the proximal right tibia on 4 h planar images; (E) Histology confirms aneurysmal bone cyst; (F) Clinical photo of resection specimen showing bony replacement and soft tissue expansion.
Aneurysmal bone cyst can originate from other precursor
lesions,eitherastheresultoftraumaoratumour-induced
vas-cularprocess Approximately30%of casesarise as a secondary
lesionin thepresence ofa primarylesion[18].We found
radi-ologicalandpathologicalevidenceoffibrousdysplasiabeingthe
primary diagnosis Our patient presented multiple times with
newsymptoms requiring repeatinvestigation,and serial
imag-ing showed the change from a benign lesion to an aggressive
lesion, butwe were unableto differentiate betweenmalignant
andbenigndiseasebasedonimagingalone.However,by
perform-ingrepeatedbiopsieswehaveshowntheclearprogressionfrom
fibrousdysplasiatoaneurysmalbonecyst,supportingthe
precur-sortheoryofsecondaryaneurysmalbonecystdevelopment.From
oursearchoftheliterature,wewereunabletofindothercasesthat
clearlyshowthedevelopmentofthesecondaryaneurysmalbone
cyst
Nguyen[18]presentedacasewithsecondaryaneurysmalbone cystoccurringinknownfibrousdysplasiaoftheproximalradius Thereweredifficultieswiththediagnosisduetoaggressivebut non-specificimagingfindings.Thispatientwassuccessfullytreated withcurettage after frozensection wasperformed onan open biopsy.Montalti[7]alsopresentedacaseofapatientwho devel-oped aneurysmal bone cyst in knownfibrous dysplasia of the proximalfemur ImagingandCT-guided biopsywereunable to excludemalignancy,buttrocharbiopsyconfirmedthediagnosis Thesecases,alongwithourcase,showthedifficultiesofearly accu-ratediagnosis,aswellasthebenefitswhenthiscanbeachieved.In ourpatient,attemptsweremadetotreatthelesionconservatively butwewereunabletocontroldiseaseprogression.Itcanbeseen thatoveratimeperiodof8monthsthelesionspreadstoinvolve all compartmentsof the legas wellas theneurovascular bun-dle.This,togetherwithmedicalcomorbidities,leadtoaboveknee
Trang 5CASE REPORT – OPEN ACCESS
56 N Anderson et al / International Journal of Surgery Case Reports 12 (2015) 52–56
amputation.Asfarasweareaware,thisistheonlyreportedcase
ofabovekneeamputationforcontrolofrapidlyprogressiveand
destructiveaneurysmalbonecyst.Oneothercaseofamputation
forbenigndiseasewasreportedbyDiercksetal.,inwhichabove
kneeamputation wasrequired fora functionless limbresulting
frommultiplefracturesduetopolyostoticfibrousdysplasia[19]
Literaturereviewrevealed35casesofaneurysmalbonecyst
occur-ringsecondarytofibrousdysplasia.Theselesionswereintheskull,
maxilla,mandible,ribs,ilium,femurandradius.Tothebestofour
knowledgethisisthefirstpublishedcaseofaneurysmalbonecyst
complicatingfibrousdysplasiaofthetibia
Wedescribe a rarecase of aggressiveaneurysmalbone cyst
occurringinthesettingofpreviouslydiagnosedfibrousdysplasia
Duetothepotentialforaggressivesecondarylesions,we
encour-agepromptfurtherinvestigationinpatientswithfibrousdysplasia
whodevelopnewsymptoms,particularlyincreasedpainor
frac-ture,orwhodevelopchangesonroutinefollow-upimaging.Early
interventionmayavoidtheneedforamputation
Theauthorsstatethattheyhavenoconflictofinterest
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NathanAnderson
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ClaudiaDiBella
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data
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MarcusPianta
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JohnSlavin
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PeterChoong
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data
Group2-Criticalrevisionofthearticle
Group3-Finalapprovaloftheversiontobepublished
Consent
Writteninformedconsentwasobtainedfromthepatientfor publicationofthiscasereportandaccompanyingimages.Acopy
ofthewrittenconsentisavailableforreviewbytheEditor-in-Chief
ofthisjournalonrequest
Guarantor
TheguarantorforthisprojectisNathanAnderson
References
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