Braz. j. . vol.82 número4

BrazJOtorhinolaryngol.2016;82(4):487---490

www.bjorl.org

Brazilian

Journal

of

OTORHINOLARYNGOLOGY

CASE

REPORT

Extramedullary

relapse

of

acute

myeloid

leukemia

mimicking

a

necrotizing

external

otitis:

could

mononuclear

leukocyte

scintigraphy

be

the

best

diagnostic

method?

夽

Recidiva

extramedular

de

leucemia

mieloide

aguda

mimetizando

otite

externa

necrotizante:

a

cintigrafia

com

leucócitos

mononucleares

pode

ser

o

melhor

método

diagnóstico?

Roberta

Laurindo

_,

_Sergio

_Souza

,

Jaqueline

Moura

,

Shiro

Tomita

,

Lea

Barbosa

da

Fonseca

_,

_Bianca

_Gutfilen

a_{ServiceofOtolaryngology,DepartmentofClinicalMedical,HospitalUniversitárioClementinoFragaFilho,UniversidadeFederal}

doRiodeJaneiro(UFRJ),RiodeJaneiro,RJ,Brazil

b_{DepartmentofRadiology,LaboratóriodeMarcac¸ãodeCélulaseMoléculas,UniversidadeFederaldoRiodeJaneiro(UFRJ),}

RiodeJaneiro,RJ,Brazil

Received26January2015;accepted23April2015 Availableonline7September2015

Introduction

Necrotizing external otitis (NEO) is an invasive infec-tious disease involving the cartilaginous and/or bony external auditory canal (EAC) that particularly affects immunocompromised patients.1 _{Patients usually present}

withunrelentingotalgiathatisdisproportionatetothe clin-ical signsand purulent otorrhea. The diagnosis of NEO is based ona combination of clinical, laboratory,and imag-ing findings.2 _{Current tools used todiagnose NEO include}

夽 _{Pleasecitethisarticleas:LaurindoR,SouzaS,MouraJ,Tomita}

S, da Fonseca LB, Gutfilen B. Extramedullary relapse of acute myeloid leukemia mimickinga necrotizing external otitis: could mononuclearleukocytescintigraphybethebestdiagnosticmethod? BrazJOtorhinolaryngol.2016;82:487---90.

∗_{Correspondingauthor.}

E-mail:[email protected](S.Souza).

computed tomography (CT), magnetic resonance imaging (MRI),andscintigraphy.Thecombinationofradiologicaland radionuclideexamsiscrucial inboth, theinitial diagnosis andthefollow-upoftreatmentresponse.

Case

report

A19-year-oldmandiagnosedwithacutemyeloidleukemia (AML)inremissionpresentedwithsevereotalgia,aural full-ness,rightfacialpalsy(scoringVontheHouse-Brackmann scale).Otoscopicfindingsincluded,edemaoftheposterior wallof theexternal earcanal and otorrhea. Diagnosis of NEOwasconsidered,andthepatientwastreatedempirically withimipenemfor12days.Thepatienthadapoorresponse toimipenem, leading the medicalteam toreplace it for cefepime.Evenafterthechangeofthetreatmentregimen thepatient’ssymptomsdidnotshowanyimprovement.

http://dx.doi.org/10.1016/j.bjorl.2015.04.003

488 LaurindoRetal.

Figure1 High-resolutioncoronalcomputedtomographyimagesofthemastoids(AandB).(A)Erosionoftheposteriorwallofthe externalauditorycanal(EAC;whitearrow)andthickeningandenhancementofthesofttissueintheregionoftheEAC(redarrow). (B)Erosionofthemastoidcortex(blackarrow)anddestructionofthebonyseptae.Magneticresonanceimagingofthemastoids (CandD).(C)Axial,T1-weightedimagedemonstratinginfiltrationofthesofttissuesaroundtheEAC,subcutaneoustissue,and parotidgland.(D)Axial,T2-Flairimageshowingthetympanicandmastoidcavity,withtissuecontrastuptakespreading anteroin-feriorly.

ComplementaryexamsrevealedhighreactiveC-protein levelsandopacificationofmastoidcellsandmiddleearinCT images,whichwasassociatedwitherosionoftheposterior wallofthe EAC(Fig.1AandB)T2-weighted MRIrevealed gadolinium enhancement inside the tympanic cavity and around the carotid canal, extending to the ear pavilion andadjacent soft tissues (Fig.1C andD). The findings of

99m_{Tc-MDPbonescintigraphywereconsistentwithan}

inflam-matory/infectiousprocessoccurringinthetemporalbone. However,99m_{Tc-mononuclearleukocytecintigraphydidnot}

showanyevidenceofaninflammatoryprocess.

Given these results and the fact that symptoms were present after 6 weeks of antibiotic therapy, the medical team considered the hypothesis that the patient had a neoplasticdisease(Fig.2).Consequently,thepatient under-went a tympanomastoidectomy. Myeloid sarcoma (MS), a typeofextramedullary recurrenceofAML, wasconfirmed

byhistopathological study.There werenosignsof disease in the bone marrow. We initiated a chemotherapy proto-coland observedrapid improvementinterms of painand by otoscopy. The facial palsy regressed to scoring III on the House-Brackmann scale after the treatment. Heterol-ogous transplantation wasrecommended,and thepatient completelyrecovered.

Discussion

MS isa rarecondition characterizedby theoccurrence of oneormoretumorscomposedofimmaturemyeloidcellsin anextramedullarysite.Thisdiseaserarelyaffectsthe tem-poral bone,and itis mostcommonly found in bones,soft tissue,skin,andthecentralnervoussystem.3_Symptomsof

Mononuclearleukocytescintigraphyandnecrotizingexternalotitis 489

Figure2 99m_{Tc-mononuclearleukocyte scintigraphy(A---C).Planar scintigraphsfrom one,three, and24hafterlabeled}

mono-nuclearleukocyteadministrationindicatenouptakealongthemastoidtopographyovertime.

palsy,tinnitus,earfullness,earpain,andretrauricularand externalauditorycanalswellingthatcanmimic otomastoidi-tisor NEO.ImagingfindingsintheearlystagesofNEOare frequentlysubtle,andeveninadvancedcases,theimaging findingsmaynotberecognizedasNEOunlessthediagnosis isalreadyunderconsideration.

Nuclearimagingplaysamajorroleinthediagnosisand follow-up of patients who have NEO. In fact, bone scans using99m_{Tc-MDPprovidebetterinformationabout}

inflamma-tionbecausetheyhighlightareaswithosteoblasticactivity. Abonescancanshowpositiveresultsbeforeapparent radio-logicalchangesoccurandmaybeusefulinearlydetection ofthedisease.However,99m_{Tc-MDPisnotspecificfor}

infec-tion,asitcanalsobepositiveinmalignantdiseaseanddoes not detect soft tissue spread without bone involvement.4

Bonescansalsoremainpositiveafterthediseaseisresolved and arenot useful for monitoring response totreatment. Gallium-67scintigraphyhasbeenshowntobe70%sensitive and93% specific todiagnose osteomyelitis; thus, it is the investigativetechnique of choice for monitoring response totreatment. CTishighlyeffectiveatdefiningtheextent ofbonydestructionintheearcanalwallorthebaseofskull bydelineatingnormalfatplanesandbonecortices,andthe importanceofCTfordiagnosingNEOiswell-established.MRI isconsideredmoresensitivethanCTfordelineatingsoft tis-sueplanes.Mostskullbaseabnormalitiesexhibitalowsignal on T1-weighted images and a high signal onT2-weighted images.5

99m_{Tc-mononuclearleukocytescintigraphyisusedto}

diag-nosisinfection,osteomyelitis,graftrejection,andfeverof unknownorigin.Itis stillconsideredthegold standardfor chronicposttraumaticorpostoperativeosteomyelitis.6,7_To

the bestof the authors’ knowledge, this is the first time

that a patient with suspected NEO has undergone 99m

Tc-mononuclearleukocytescintigraphy.Inthiscase,thebone scintigraphywaspositive,CTdemonstratederosionofthe bone inthe earcanal wall, andMRI wascompatible with an inflammatory response. The only finding that did not corroborate an inflammatory/infectious etiology was the

99m_{Tc-mononuclearleukocytescintigraphy,whichwasmore}

compatiblewithaneoplasticetiology.

Conclusion

NEO has a variety of clinical presentations and, conse-quently, a broad range of radiological appearances. In the case reported here, the clinical findings and most of the radiological examinations led this group to diag-nose the patient with NEO and to initiate treatment. The99m_{Tc-mononuclearleukocytescintigraphywastheonly}

radiologicalexaminationthatmorecloselyalignedwiththe eventual histopathologicalfindings. Additional studies are underwaytodetermineifleukocytescintigraphycouldbea betteroptionfordiagnosingNEOthanothermethodsmore commonlyappliedinclinicalpractice.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

References

490 LaurindoRetal.

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4.Chen CN, Chen YS, Yeh TH, Hsu CJ, Tseng FY. Outcomes of malignant otitis: survival vs mortality. Acta Otolaryngol. 2010;130:89---94.

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