Thyroid lipoadenoma: a case report of a rare condition

BrazJOtorhinolaryngol.2014;80(6):542---543

Brazilian

Journal

of

OTORHINOLARYNGOLOGY

www.bjorl.org

CASE

REPORT

Thyroid

lipoadenoma:

a

case

report

of

a

rare

condition

夽

Lipoadenoma

de

tireoide:

relato

de

caso

desta

rara

apresentac

¸ão

Giulianno

Molina

de

Melo

,

Natalya

de

Andrade

Bezerra

,

Lais

Pacca

Nicolellis

,

Bruno

Costa

Fontainha

_,

_Ricardo

_Antenor

_de

_Souza

_e

_Souza

a_{‘‘JorgeFairbanksBarbosa’’DepartmentofClinicandHeadandNeckSurgery,HospitalBeneficênciaPortuguesadeSãoPaulo,}

UniversidadeFederaldeSãoPaulo(UNIFESP),SãoPaulo,SP,Brazil

b_{HospitaldaBeneficênciaPortuguesadeSãoPaulo,BrazilianSocietyfortheProgressofScience(SBPC),SãoPaulo,SP,Brazil}

Received2December2012;accepted8April2013 Availableonline4July2014

Introduction

Lipoadenoma,thyrolipoma, or adenolipoma is an exceed-inglyrarebenignlesionformedbyfatandthyroidtissue.1---3

Its origin is unknown; a number of authors explain it as

anabnormalityarisingduringthyroidencapsulationorfrom

fibroblastmetaplasiafollowing hypoxia.3---5 _{The distinction}

betweenthyroidandparathyroidlipoadenomaissubtleand

requiresconfirmationwithapositivethyroglobulintest.The

clinicalpresentationisoneofthyroidnodules,withor

with-outcompressivesymptoms.2,3

Case

report

L.R.,a 53-year-oldfemalepatient,presentedwitha

one-yearhistoryofasolitaryenlargingthyroidmass.Onphysical

夽 _{Pleasecitethisarticleas:deMeloGM,BezerraNA,NicolellisLP,}

FontainhaBC,deSouzaeSouzaRA.Thyroidlipoadenoma:acase reportofararecondition.BrazJOtorhinolaryngol.2014;80:542---3.

∗_{Correspondingauthor.}

E-mail:[email protected](G.M.deMelo).

examination, a 2-cm fibroelastic nodule on the left

thy-roid lobe and 4-mm nodules and cysts on the right lobe

werefound.Laboratorytestswerenormal,andfine-needle

aspirationof the2-cmnodulerevealed thelesion tohave

a follicular pattern. Total thyroidectomy was performed

and frozen sections confirmed a follicular lesion.

Follow-ingimmunohistochemicalstaining,thediagnosiswasthyroid

lipoadenoma(Fig.1).

Discussion

Fattissueinthethyroidglandisnotcommon;itismoreoften

found macroscopicallyor microscopically3---5 _{inparathyroid}

glands, breast, thymus, salivary glands, and pancreas2,3

in a diffuse or encapsulated arrangement. Itsbehavior is

benign, but as it increases in size it can cause cervical

enlargement and compressivesymptoms,such asdyspnea

anddysphagia.1---3 _{Inthepresent report,thesymptomwas}

aslowlyenlargingcervicalswelling.Ultrasonographyisthe

mostcommonprocedureusedinthework-up,followedby

fine-needleaspiration,asrecommendedintheATAandLATS

guidelines,3,5 _{but the lesion is souncommon, there is no}

differentialdiagnosislistedforlipoadenoma.

http://dx.doi.org/10.1016/j.bjorl.2014.05.023

Thyroidlipoadenoma 543

Figure1 Lipoadenomainthyroidglandencapsulatednodule. HE 100×, Thickshorter arrow, adipocyte accumulation; thin

longerarrow,benignfollicularcells.

Therearefewerthan30reportsofadenolipomasinthe

literature,andmostcasesarethatoffemalesintheirfifties,

similartothecasereportedhere.2,5,6_{Inaliteraturereview}

on MEDLINE, using lipoadenoma as the indexer between

November of 1971 and January of 2012, 46 reports were

retrieved, but none of them assessed thyroid gland

ade-nolipoma.ByusingtheLILACSplatform between1982and

2000, three reports with the keyword adenolipoma were

retrieved,butnoneofthemdiscussedthyroidadenolipoma

orlipoadenoma.ThesearchusingadiposetissueANDthyroid

glandtissueencompassesfourdifferentialdiagnoses:

papil-larycarcinoma,intrathyroidalthymiclipoma,intrathyroidal

parathyroidlipoma,andlipoadenoma.1,3,5,6

In the literature, patients with lipoadenoma had

nor-mal thyroid glandfunction and scans,as didour patient,

inwhomthefine-needleaspirationdiagnosisrevealedonly

a follicular-pattern lesion and did not show the

pres-ence of adipose tissue. A lack of cytological criteria

differentiatingathyroidlipoadenomafromathyroid

follic-ularlesionwaslikelythecause.2,5,6_{Thedefinitivediagnosis}

from the pathology and immunohistochemical staining

reportswasmadeonlyaftersurgery,asistypicalforcases

described in the literature.1,2 _{In our report, total}

thy-roidectomywasperformedconsistentwiththecriteriafrom

the literature for thyroid gland nodules, since the

speci-menswerefrombilateral nodulesand requireddiagnostic

elucidation.3,4_{Thepatientcurrentlymaintainsnormal}

thy-roidhormonelevelsthroughlevothyroxinereplacement.

Thepresentreportaimedtoaddmoredatatothe

liter-ature,withthepurposeofbetterunderstandingofthisrare

condition,andpossiblytopromoteamanagementchangein

ordertoavoidsurgicalapproachinselectedcases.

Final

remarks

Thepresentreportconcludesthatthecorrectpreoperative

diagnosisofthyroidlipoadenomaisstilldifficultduetothe

rarityofthiscondition.Thedefinitivetreatmentconsistsof

totalsurgicalresectionand,duetoitsbenignhistology,the

outcomeisveryfavorable.Furtherstudieswithcytological

criteriaarerequiredtore-evaluatetheneedforsurgeryin

thesecases.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

References

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2.VelozaA,ManitaI,CoelhoC,SaraivaC,NascimentoI,OliveiraA, etal.Adenolipomadatiroide.ActaMedPort.2010;23:277---80.

3.HjorthL,ThomsenLB,NielsenVT.Adenolipomaofthethyroid gland.Histopathology.1986;10:91---6.

4.BorgesA,CatarinoA.Adenolipomaofthyroidgland.Radiology. 2002;225:746---50.

5.DaboinKP,PerezV,LunaM.Adenolipomaoftheheadandneck: analysisof6cases.AnnDiagnPathol.2006;10:72---6.