Horizontal histological sections in the preliminary evaluation of basal cell carcinoma submitted to Mohs micrographic surgery,

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Anais

Brasileiros

de

Dermatologia

www.anaisdedermatologia.org.br

INVESTIGATION

Horizontal

histological

sections

in

the

preliminary

evaluation

of

basal

cell

carcinoma

submitted

to

Mohs

micrographic

surgery

夽,夽夽

Poliana

Santin

Portela

a,∗

_,

_Danilo

_Augusto

_Teixeira

b

_,

Carlos

D’Aparecida

Santos

Machado

c

_,

_Maria

_Aparecida

_Silva

_Pinhal

d

_,

Francisco

Macedo

Paschoal

c

a_Graduate_Program_in_Health_Sciences,_Faculdade_de_Medicina_do_ABC,_Santo_André,_SP,_Brazil

b_Department_of_Dermatology,_Hospital_de_Doenc_¸as_Tropicais,_Goiânia,_GO,_Brazil

c_Discipline_of_Dermatology,_Faculdade_de_Medicina_do_ABC,_Santo_André,_SP,_Brazil

d_Discipline_of_{Biochemistry,}_Faculdade_de_Medicina_do_ABC,_Santo_André,_SP,_Brazil

Received23July2016;accepted26November2017 Availableonline26October2019

KEYWORDS Carcinoma,basal cell; Mohssurgery; Pathology Abstract

Background: Mohs micrographic surgery is a surgical technique for the treatment of

non-melanomaskin cancer.Surgery beginsby removing thevisibletumor before excisionofthe tissuespecimensforevaluationofthetumormargins.

Objectives: Topresentanewwaytoevaluatethematerialobtainedfromdebulking,by

hori-zontalhistologicalanalysisofthefragment.

Methods: Descriptiveretrospectivecross-sectionalstudybasedonthemedicalrecordsand

his-tologicallamellaeofpatientswithprimarybasalcellcarcinomassmallerthan1.5cmsubmitted toMohsmicrographicsurgeryandwhohadthevisibletumoranalyzedbyhorizontalhistological sections.

Results: Thesampleevaluatedincluded16patientswithlesionslocatedontheface.Comparing

the histopathologicalexaminations ofincisional biopsyinvertical sectionsanddebulking in horizontalsections,therewasagreementinsevencases.Thehistologicalanalysisperformed inhorizontalsections allowedidentiﬁcation ofthetumorsite in13 cases,andthe relation betweentumorandmarginshowedthatin11cases,thelateralmarginwascompromised.

Studylimitations:Thetechniquewasbetter-appliedinlesionssmallerthan2cm.

夽 _How_to_cite_this_article:_Portela_PS,_Teixeira_DA,_Machado_CDS,_Pinhal_MAS,_Paschoal_FM._Horizontal_histological_sections_in_the_preliminary

evaluationofbasalcellcarcinomasubmittedtoMohsmicrographicsurgery.AnBrasDermatol.2019;94:671---6.

夽夽_Study_conducted_at_the_Faculdade_de_Medicina_do_ABC,_Santo_André,_SP,_Brazil. ∗_{Corresponding}_author.

E-mail:[email protected](P.S.Portela). https://doi.org/10.1016/j.abd.2017.11.001

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672 PortelaPSetal.

Conclusion: HorizontalhistologicalanalysisofdebulkinghasadvantagesforMohssurgery,since

itallowsvisualizationofalmostalltumorextensioninthesameviewplaneofthedermatoscopy, allowingbetterdeﬁnitionofthehistologicalsubtype,tumorsite,andtumor/marginoflesions lessthan1.5cm.

Introduction

Mohsmicrographicmurgery(MMS)isasurgicaltechniquefor thetreatmentofnon-melanomaskincancer.1_It_consists_of

a seriesof standardized steps with precise and complete histological control of tumor margins, with superior cure rates,andmaximumpreservationofnormaltissuein rela-tiontoconventionalsurgery.2_The_correlation_between_the

presenceof tumor in the histologicalexamination and its correctlocationonthesurgicalmapisessentialforcomplete resectionofthelesionandpreservationofnormaltissue.1

Thesuccessofmicrographicsurgeryisinherentlylinked tothereliabilityofeachofthemanystepsthatmakeupthe technique.3_Since_its_ﬁrst_description_by_Frederic_E._Mohs,4

micrographicsurgeryhas beenundergoingaconstant pro-cessofmodiﬁcationsandadaptations,withtheobjectiveof developingtechnicalvariationsthatbestadapttothedaily routineofdermatologicsurgeons.However,thebasicsteps oftheprocedurearepreserved4_:

(1) Tumorremoval;

(2) Delimitationofamarginrangingfrom2---5mmdepending onhistologicaltypeandtumorlocation;

(3) Removalofthintissuelayercontainingthelateral mar-ginsandtumorbed;

(4) Mappingofthesurgicalspecimen;

(5) Microscopicanalysiswithtotalcontrolofmargins; (6) Selectiveexcisionofareaswithresidualtumor; (7) End of the excision after obtaining free margins and

posteriorreconstructionofthesurgicalwound. Beforesurgicalprocedurebegins,thetumorsiteis iden-tiﬁed and marked with a dermatoscope. This allows the precisedelimitationof thevisible tumor andthecreation ofasurgicalmargin of1---5mm,dependingontumor type. Surgery begins with debulking or enucleation, involving removalofthevisibletumorpriortoexcisionoftissue spec-imensforevaluationoftumormargins.Therearedifferent waysofperformingenucleation.Somesurgeonsmakevisible tumorcurettageinordertobetterdelimitatethemargins, othersopttohistologicallyevaluatetheexcisedmaterial.5

Traditionally, the histological analysis of the material from enucleation is performed by conventional incisions, i.e.,in verticaltransverse sections.This is madefor doc-umentation andtoidentify speciﬁc tumor growthpattern withinthetissue,especiallyifthebiopsywasnotdeﬁnitive.5

However,thedisadvantages ofthis analysisfallunderthe sameconditionsoftheconventionalpathology,whereonly averysmallsampleofthetumorisstudied.6_Serial_vertical

incisionsaremadeat2---4mmintervalsintheconventional method of evaluation (bread-loaf method). This leaves

marginal areas between sectionsthatare not microscopi-callyvisualized,andlessthan1%ofthetumormarginsare evaluated.5

Basedonreﬂectanceconfocalmicroscopy,whereimages areparalleltothesurfaceathorizontalorientation,which allows a broader analysis of the tumor architecture, this studyaimedtopresentanewwayofevaluatingthetumor enucleationmaterialfromthehorizontalhistological analy-sisofthefragmentresultingfromtheremovalofthevisible tumorobtainedbyenucleationintheﬁrststepofMMS.7,8

Objectives

To comparethehistologicaltypeofhorizontalhistological analysisoftheenucleationwiththeverticalhistologicaltype ofthepreoperative biopsyandtoevaluatetherelation of thetumorwiththemarginoftumorresection.

Methods

This wasa descriptive retrospective cross-sectional study basedonthe medicalrecordsandhistologicallamellae of patientswithprimarybasalcellcarcinomas(BCCs)smaller than1.5cmsubmittedtoMMSandwhohadthevisibletumor analyzedbyhorizontalhistologicalsections.Thestudywas submittedandapprovedbytheethicscommittee. Epidemi-ologicaldatawerecollectedfrompatients’records,suchas sex,age,histologicaltypedefinedbypreviousbiopsybythe pathologist,histologicaltypedefinedbyhorizontal histolog-icalincision,tumorsize,initialandfinalsizeofthesurgical defect, numberofphases necessary for complete surgical excision, and type of reconstruction adopted. Data were collectedandenteredintoanExceltable.Thehistological slidesfromsurgerieswerereviewedandanalyzed,defining thehistologicalsubtype ofthe tumorand itsproximity to theexcisedmargins.

Inallcases,thefollowingstepswereperformed: (1) Preoperativedelineation(ormarking)ofthetumor

mar-ginswithalightingandimagemagniﬁcationinstrument, thedermatoscope3GENDermLiteIIhybridm.

(2) After the steps of asepsis, antisepsis, and inﬁltrative anesthesia,thesurgicalprocedurebeganwiththe enu-cleationstage. This stepconsists of the excision of a thinlayeroftheentirevisiblelesion(areadelimitedby dermoscopy)forhorizontalhistologicalanalysis. (3) Afterenucleation,amarginof2mmwasaddedtothe

areathatwasremovedandotherMMSstageswere per-formed.

(4) Horizontalhistologicalsectionsweretakenfromthe sur-facetothedepthandtheauthorsevaluateddatasuch

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Figure1 Clinicalanddermatoscopicaspect(×20magniﬁcation)ofbasalcellcarcinomalocatedintheleftmalarregion.

Figure2 Tumordelimitationwithdermatoscope.

ashistologicalsubtype,initial tumor size,and tumor-marginrelationship.

The casepresented inFigs.1---5illustratesthe step-by-stepineachoftheevaluatedcases.

Results

Thesampleevaluatedincluded16patients,fourmalesand 12 females, aged between 50 and 84 years (Table 1). All lesionswerelocatedontheface,allofthemsmallerthan 1.5cm in diameter. The predominant subtype of BCC in preoperativebiopsyanalysiswasnodularor solidform(six cases),followedbyinﬁltrativesclerodermiform(fourcases), nodular and micronodular (four cases), and micronodular (twocases).Comparingthehistopathologicalexaminations

of incisionalbiopsy in vertical sections and the debulked pieceinhorizontalsections,therewasagreementinseven casesanddisagreementinninecases.Vertical histopatho-logical analysis(preoperative punch biopsy)wasincorrect infourcasesofthe16evaluatedandfailedtoidentify inﬁl-trativeforms ofBCCsin twocases,whichwerediagnosed as nodular and micronodular BCCs, but in the horizontal histological analysis of the debulking, they corresponded tomicronodular BCCs. In thesecases, even though there wasnototalagreement,thepreoperativebiopsydiagnosed themicronodular inﬁltrative portion. In oneof the slides evaluatedbyhorizontalincisions,itwasnotpossibleto iden-tifythepresenceoftumortissue.

The histological analysis of the visible tumor of each patient performed by horizontal incisions allowed identi-ﬁcation of the tumor site in 13 cases, and the relation

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674 PortelaPSetal.

Figure3 Debulkingimageanddemonstrationofhowtheincisionsweremade(horizontalincisionsfromthesurfacetothedepth ofthetumor).

Figure4 Horizontalhistologicalsectionsofthedebulking(hematoxylin-eosin,×20).Topleftimagecorrespondingtothesurface incisionandlowerrightimagetothedeepestincision.Highlightedlateralmargininvolvement(redrectangle).

between tumor and margin showed that in 11 cases, the lateralmargin wascompromised.Eight casesneeded only onesurgical phase,six patients hadto undergo a second phase,andonepatientrequiredfourphasesfor totalBCC excision.

Discussion

Traditionalpre-operative biopsies of cutaneous malignan-ciesareperformedtoprovideaccuratediagnosisofclinically

diagnosedtumorsandhencetoindicatethebesttreatment. Whenthesetumorsaredeﬁnitivelytreatedbysimple exci-sion, the piece is sent to the pathology department and the general architecture of the central tumor nodule is furtherhistologicallyevaluated,duringwhichany inconsis-tenciesareobserved.Ifthesametumorisexcisedthrough Mohstechnique,thesurgicalmarginreceivescomplete eval-uationbythesurgeonhimself,allowingthepreservationof tissue,resultingin highercurerates. However,the tumor itselfwillneverbeseeniftheﬁrstphaseoftheMohssurgery

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Figure5 Microscopicviewofthehorizontalhistological inci-sionwithcompromisedmargin(hematoxylin-eosin,×100).

hastumor-freemargins,andthepreoperativebiopsyisthe onlysampleoftheactualtumor.Inrarecases,initialbiopsy sampling error and/or limitations in the dermatopatholo-gist’s ability toassess the overall morphology of a tumor basedonasmallbiopsymaylimittheabilitytomakea cor-rectdiagnosis.Thismayhavediagnosticand/ortherapeutic implications.6

WhenthevisibleportionoftheBCCisremovedby curet-tageor excisionofthetumorfor conventionalhistological evaluation, the question is whether or not some tumor characteristic is missed by not performing the complete histologicalanalysis.Inmostcases,theanswertothis ques-tion is no.6 _However, _the _horizontal _incision_serves _as_an

important guideline in the planning processof MMSor in subsequentphases.Inthisway,thesurgeonhasavisionof 100%ofthetumor,andthuscandeﬁnemorecharacteristics, suchasitshistologicalsubtype,lateralmargininvolvement, andlateralgrowthpattern.

Animportantquestion isthis:Whatstepscanbetaken tominimizediagnosticinadequaciespriortoMohssurgery?6

One way to minimize the diagnostic inaccuracies for the Mohs surgeon is to evaluate the intraoperative debulk-ing specimens obtained in horizontal sections. Horizontal histologicalanalysis,i.e.,paralleltothesurfaceofthe epi-dermis,providesabetterstudyoftumorshape,beingableto mapitandbetterdelimitthesurgicalmargin.Thisisbecause somesubtypesofBCCshavesmallextensionsorrootsthat maynotbeseeninconventionalverticalincisions.9

Conclusion

MMS has come to minimize diagnostic inaccuracies while providing the patient with optimal treatment for many cutaneous neoplasms. Horizontal histological analysis of debulking has advantages for Mohs surgery, since it pro-videsthesame viewof thetumor asconfocal microscopy anddermoscopy,allowingbetterdeﬁnitionofthe histolog-icalsubtype,a moredeﬁnite view ofthe tumor siteand, in lesionssmaller than 1.5cm,visualization of the entire tumor,providingagoodideaofthetumor’srelationshipwith themarginofthelesion.

Table1 Clinicaldata,histologicalﬁndings,andtumorcharacteristicsofthe16casesanalyzed

Case Sex Age

(years)

Location Size(cm) BCCsubtypeof previousbiopsy (histology) BCCsubtype ofdebulking (histology) Number ofMMS phases Involvement oflateral margins Adequate identiﬁcation oftumorsite

1 M 64 Forehead 0.8×0.7 Sclerodermiform Sclerodermiform 2 Involved Yes

2 F 82 Cheek 1.9×1.9 Nodular Nodular 1 Involved Yes

3 F 57 Inferior

eyelid

2.0×1.5 Nodular Micronodular 1 Involved Yes

4 M 51 Inferior

eyelid

1.0×0.8 Nodular Nodular 1 Involved Yes

5 F 69 Nose 0.6×0.5 Micronodular Micronodular 1 Free Yes

6 F 64 Nose 0.8_×0.7 Nodularand

micronodular

Micronodular 1 Involved Yes

7 F 84 Nose 0.7×0.6 Sclerodermiform Sclerodermiform 1 Involved Yes

8 M 53 Nose 1.0×1.0 Nodular Notumor 1 Free No

9 F 64 Nose 1.3×0.9 Sclerodermiform Micronodular 1 Involved Yes

10 F 79 Nose 0.8_×0.7 Nodularand

micronodular

Micronodular 5 Free Yes

11 F 50 Inferior

eyelid

0.9_×0.6 Nodularand micronodular

Micronodular 2 Involved Yes

12 M 70 Nose 1.2×1.2 Sclerodermiform Superﬁcial 2 Free No

13 F 79 Cheek 0.7×0.6 Nodularand

micronodular

Nodular 2 Involved Yes

14 F 68 Nose 0.4_×0.3 Micronodular Micronodular 2 Involved No

15 F 60 Nose 1.0×0.7 Nodular Nodular 2 Involved Yes

16 F 63 Inferior

eyelid

0.45_×0.45 Nodular Micronodular 1 Involved Yes

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676 PortelaPSetal.

Financial

support

Nonedeclared.

Author’s

contribution

Poliana Santin Portela: Conception and planning of the study;elaborationandwritingofthemanuscript;obtaining, analyzing and interpreting the data; intellectual partici-pationin propaedeuticand/or therapeuticconduct ofthe cases studied; critical review of the literature; critical reviewofthemanuscript.

Danilo Augusto Teixeira: Elaboration and writing of themanuscript; intellectual participation inpropaedeutic and/ortherapeuticconductofthecasesstudied.

Carlos ´DAparecida SantosMachado:Effective participa-tioninresearchorientation.

Maria AparecidaSilva Pinhal: Effective participationin researchorientation.

FranciscoMacedoPaschoal:Approvaloftheﬁnalversion of themanuscript; conception and planningof the study; obtaining, analyzing and interpreting the data; effective participation in research orientation; intellectual partici-pationin propaedeuticand/or therapeuticconduct ofthe cases studied; critical review of the literature; critical reviewofthemanuscript.

Conﬂicts

of

interest

Nonedeclared.

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