neoplasms Oral tonsil in the floor of mouth: Ectopic oral tonsillar tissue simulatingbenign Oral Science International

OralScienceInternational9 (2012) 29–31

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Oral Science International

j ou rna l h o m e p a g e :w w w . e l s e v i e r . c o m / l o c a t e / o s i

Case report

Oral tonsil in the floor of mouth: Ectopic oral tonsillar tissue simulating benign neoplasms

Koji Kashima

, Koichi Takamori, Kaori Igawa, Izumi Yoshioka, Sumio Sakoda

DepartmentofOralandMaxillofacialSurgery,MiyazakiMedicalCollege,5200Kihara,Kiyotake-choMiyazaki889-1692,Japan

a r t i c l e i n f o

Articlehistory:

Received4May2011

Receivedinrevisedform12January2012 Accepted17January2012

Keywords:

Oraltonsils Floorofthemouth Lymphoepithelialcyst

a b s t r a c t

Oraltonsils,ectopicsublingualtonsillartissue,manifestasanasymptomatic,nonulcerated,freelymov- ablenodule.Wepresentacaseofa28-year-oldfemalewithectopictonsillartissueintheanteriorfloorof themouth.Thelesionwastotallyremovedunderlocalanesthesia.Themicroscopicexaminationshowed welldemarcatedandencapsulatedlymphoidtissuewithlymphoidfolliclesandcentrallacuna-likesqua- mousepitheliumcoveringspace.Thesefindingsaresimilartotonsillartissue,andthecasewasfinally diagnosedassublingualoraltonsil.Thisarticleunderlinesthatoraltonsilsoccurmorefrequentlythanis generallyrecognized,andtheimportanceofdifferentialdiagnosisofsofttissuenodulesintheoralfloor.

© 2012 Japanese Stomatological Society. Published by Elsevier Ltd. All rights reserved.

Oraltonsils,theoccurrenceofectopictonsillartissue,arefound intheoralcavity,andmanifestasanasymptomatic,nonulcerated, freelymovablenodulegenerallylocatedontheanteriorfloorof themouth[1,2].It hasalsobeenconsideredasrepresentingan earlystagein thedevelopmentofa lymphoepithelialcyst[3,4].

Weherewithreporta caseofa28-year-oldfemalewithectopic tonsillartissuetoremindoralsurgeonsofitsoccurrenceandthe needtoconsiderthelesioninthedifferentialdiagnosisofsofttissue noduleswhenfoundintheanteriorfloorofthemouth.

1. Casereport

A female patient aged 28years visited us complaining of swelling in the anterior floor of the mouth, because 2weeks previouslyherdentistnoticedthepresenceofa swellinglesion duringaroutineoralexamination.Hermedicalhistoryandfam- ilyhistorywereunremarkable.Shedidnotusetobaccoanddrank a small amount of alcohol. Careful inspection revealed a well- circumscribed,smooth,round,painless,swellingcoveredbyintact normal-appearingmucosa,freelymovablefromtheunderlining tissue,measuring4mm indiameterin theanteriorfloorofthe mouth(Fig.1).Ageneralphysicalexaminationrevealedneither lymphadenopathynorevidenceof systemicdiseases.Thelesion wasclinicallydiagnosedassalivaryglandtumor,andtheclinical differentialdiagnosisincludedmucocele,lipoma,lymphoepithe- lial cyst,and epidermoid cyst. The lesion was totally removed

∗ Correspondingauthor.Tel.:+81985853786;fax:+81985857190.

E-mailaddresses:kojikash@post.miyazaki-med.ac.jp, qq954eh9k@vega.ocn.ne.jp(K.Kashima).

underlocalanesthesia.Duringremoval,it wasfoundtobewell circumscribedandnotadherenttotheoverlyingmucosa(Fig.2).

Thewoundwasclosedprimarilyandhealedwithoutcomplication.

Norecurrencewasobservedaftera1-yearfollow-upperiod.The microscopeexaminationshowedwelldemarcatedlymphoidtis- sueencapsulatedwithfibrousconnectivetissue,whichconsistedof abundantreactivelymphoidaggregateswithwell-formedgermi- nalcenters.Therewasanon-dilatedcentralcryptlinedbystratified squamousepitheliumandcontainingdesquamatedepithelialcells andkeratindebrisinacentrallacuna-likespace.Serialsectionsof thelesiondidnotrevealcontinuityoftheliningepitheliumwiththe superficialepithelium.Nocysticformationwasfoundinthespec- imen.Thesefindingsaresimilartothoseoftonsillartissuerather thanlymphoepithelialcyst,andthecasewasfinallydiagnosedas sublingualoraltonsil(Figs.3and4).

2. Discussion

Itiswellknownthatlymphoidtissuesuchaspalatine,lingual tonsilsandpharyngealadenoidsconstituteWaldeyer’sringinthe pharynxandtheoralcavity.Itislessorganizedandthesmallerlym- phoidaggregationcanoccurcommonlyinthefloorofthemouth, theventralsurfaceofthetongue,andthesoftpalate[3].Although lymphoid tissueaggregates occurfrequentlyintheoral floor,a searchoftheliteraturesuggeststhatlesionsoriginatingfromlym- phoidtissuesuchasectopictonsillartissueorlymphoepithelialcyst arerare[1].Thispaucityintheliteratureofreportedcasesisprob- ablyduetothesmallsizeandasymptomaticnatureofthelesion, andcanbeeasilyoverlookedinconsequence[5].

Thelymphoepithelialcystisasofttissueepithelialcystasso- ciatedwithlymphoidtissue.Itisasymptomaticandsmall,rarely 1348-8643/$–seefrontmatter © 2012 Japanese Stomatological Society. Published by Elsevier Ltd. All rights reserved.

doi:10.1016/S1348-8643(12)00006-7

30 K.Kashimaetal./OralScienceInternational9 (2012) 29–31

Fig.1. Smallswellingonthefloorofthemouth(arrows).

Fig.2. Grossviewofthetonsillartissue,smooth,encapsulatedandmeasured 5mm×4mm×4mminsize.

Fig.3.Lowpowerphotomicrographshowswell-circumscribedcollectionoflym- phoidtissuewithnumerousfolliclesandcentralepithelium-linedspacefilledwith parakeratoticmaterial.(Hematoxylinandeosin.Originalmagnification×20.)

Fig.4.Higherpower photomicrographdisplays lymphoidfolliclesandcentral epithelium-linedspaceareacontainingepithelialandkeratindebrisinmoredetail.

(Hematoxylinandeosin.Originalmagnification×100.)

exceedingadiameterover15mm.Thefloorofthemouthisthe mostcommonsitewithaproportionof65.3%,followedby13.7%

ofcasesofposterolateralportionofthetongue[3].Thislesionhas beenalsocalledabranchialcyst,abranchiogeniccyst,oralym- phoepitheliallesion[1].Theetiopathogenesisoflymphoepithelial cystsisamatterofdebateintheliterature,butsomeauthorshave consideredthelymphoepithelialcystintheoralfloorasthesame entityoranearlierstageofsublingualtonsil[3,4].Knappsuggested thatlymphoepithelialcystoftheoralcavityrepresentsadilated, obstructedcryptoftheoraltonsilwitheitherpurulentmaterialor desquamatedkeratinocytes[3].Furthermore,BuchnerandHansen had classifiedoral tonsilsinto4 groups;fromthenormal, nar- rowcrypt,through themoderatelydilated crypt,tothewidely dilatedcrypt,andsuggestedthatoraltonsilsmayrepresentanear- lierstageinthedevelopmentofalymphoepithelialcystthatthe liningepitheliumofthecystseparatesfromthesuperficialepithe- liumatlaterstages[4].Inthepresentcase,thelymphoidelements wereprominent,thecryptwasnotdilatedandnocysticformation wasfound.Serialsectionsofthelesiondidnotrevealcontinuity oftheliningepitheliumwiththesuperficialepithelium,probably duetomissingthefindingoftheconnectionbetweenlumenand oralcavity.AcevedoandNelsondidnotfindanycommunicationor continuitybetweenthemucosalepitheliumandliningepithelium ofthecrypts[6].Buchneretal.alsoreportedthattherewereonly twocasesinaseriesof38cases,inwhichtheliningandthesurface epitheliumwerecontinuous[4].Anotherpossibleexplanationthat hasbeensuggestedislocaltraumaandobstructedtonsillarcrypts.

BuchnerandHansensuggestedthatinflammationthataccompa- niestraumaleadstothedevelopmentofthelymphoepithelialcyst, andthepresenceofpolymorphonuclearleukocytesinthelumenof thelymphoepithelialcystcouldsupportevidenceofinflammation thatledtotheobstructionofthecryptoftheoraltonsilandthe developmentofthecyst[4].Inourcase,therewasnohistoryofan accidentaltraumainthefloorofthemouthaswellasthepresence ofpolymorphonuclearleukocytesinthelumen.

Minutelymphoidtissueaggregatesarenormallyfoundinthe floorofthemouth[3].Pathologicchanges,commonlyhyperplasia fromantigenicstimulation,cancausetheselymphoidaggregations tobecomemore clinically evident. Theynormallyappear clini- callyasasymptomatic,small,soft,swellingssituatedimmediately beneaththesurfaceepithelium,anditisimpossibletodetermine thetruenaturefromtheirclinicalappearance[2,7].Thedifferen- tialdiagnosisincludesmucocele,lipoma,amyloidalnodule,salivary

K.Kashimaetal./OralScienceInternational9 (2012) 29–31 31

glandtumor,neuraltumor,andlymphoma,andthetreatmentof oraltonsilsconsistsofconservativesurgicalremoval.Microscopic examinationisindicatedtoruleouta developmentalprocessof malignancy[2,4,7].

Finally, this article underlines that oral tonsils occur more frequentlythanisgenerallyrecognized,andtheimportanceofdif- ferentialdiagnosisofsofttissuenodulesintheoralfloor.

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[3]KnappMJ.Pathologyoforaltonsils.OralSurgOralMedOralPathol1970;29:

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[4]BuchnerA,HansenLS.Lymphoepithelialcystsoftheoralcavity.Aclinico- pathologicstudyofthirty-eightcases.OralSurgOralMedOralPathol1980;50:

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[5] MogiK.Ectopictonsillartissueinthemucosaofthefloorofthemouthsimulating abenigntumour.Casereport.AustDentJ1991;36:456–8.

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