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
a,∗,
Natalya
de
Andrade
Bezerra
a,
Lais
Pacca
Nicolellis
a,
Bruno
Costa
Fontainha
a,
Ricardo
Antenor
de
Souza
e
Souza
ba‘‘JorgeFairbanksBarbosa’’DepartmentofClinicandHeadandNeckSurgery,HospitalBeneficênciaPortuguesadeSãoPaulo,
UniversidadeFederaldeSãoPaulo(UNIFESP),SãoPaulo,SP,Brazil
bHospitaldaBeneficênciaPortuguesadeSãoPaulo,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:giulianomolina@hotmail.com(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.2,5,6Inaliteraturereview
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.2,5,6Thedefinitivediagnosis
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.3,4Thepatientcurrentlymaintainsnormal
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.