Frozen Section Library: Appendix, Colon, and Anus Forfurthervolumes: http://www.springer.com/series/7869 Frozen Section Library: Appendix, Colon, and Anus Nicole C. Panarelli, MD WeillMedicalCollegeofCornellUniversity,NewYork,NY Rhonda K. Yantiss, MD WeillMedicalCollegeofCornellUniversity,NewYork,NY 123 NicoleC.Panarelli RhondaK.Yantiss WeillMedicalCollege WeillMedicalCollege CornellUniversity CornellUniversity 525East68thSt. 525East68thSt. 10065NewYork,NY 10065NewYork,NY USA USA [email protected] [email protected] ISSN1868-4157 e-ISSN1868-4165 ISBN978-1-4419-6583-7 e-ISBN978-1-4419-6584-4 DOI10.1007/978-1-4419-6584-4 SpringerNewYorkDordrechtHeidelbergLondon LibraryofCongressControlNumber:2010930654 ©SpringerScience+BusinessMedia,LLC2010 Allrightsreserved.Thisworkmaynotbetranslatedorcopiedinwholeorinpart withoutthewrittenpermissionofthepublisher(SpringerScience+BusinessMedia, LLC,233SpringStreet,NewYork,NY10013,USA),exceptforbriefexcerptsin connectionwithreviewsorscholarlyanalysis.Useinconnectionwithanyformof informationstorageandretrieval,electronicadaptation,computersoftware,orby similarordissimilarmethodologynowknownorhereafterdevelopedisforbidden. Theuseinthispublicationoftradenames,trademarks,servicemarks,andsimilar terms,eveniftheyarenotidentifiedassuch,isnottobetakenasanexpressionof opinionastowhetherornottheyaresubjecttoproprietaryrights. Whiletheadviceandinformationinthisbookarebelievedtobetrueandaccurate atthedateofgoingtopress,neithertheauthorsnortheeditorsnorthepublisher canacceptanylegalresponsibilityforanyerrorsoromissionsthatmaybemade. Thepublishermakesnowarranty,expressorimplied,withrespecttothematerial containedherein. Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) Preface Despitemanyrecentadvancesinancillarytechniques,intraopera- tivepathologyconsultationremainsoneofthemostdiagnostically and technically challenging areas of surgical pathology. Frozen sections are usually performed while the patient is under general anesthesia and often form the basis for making immediate treat- ment decisions. Therefore, pathologists must render a diagnosis quickly, despite the pitfalls and artifacts associated with frozen section preparation. Unfortunately, most standard pathology text- books largely ignore the topic of frozen section, and the value ofgrossexaminationofsurgicalresectionspecimensisnolonger emphasizedinmanytrainingprograms. Frozen Section Library: Appendix, Colon, and Anus is a vol- ume in the Frozen Section Library Series. The book is divided into seven chapters, each of which discusses the clinical context in which a frozen section consultation may be requested. The chaptersemphasizegrosscharacteristicsofdisordersofthelower gastrointestinaltract,addresscommonquestionspathologistsmust answer during frozen section examination, and discuss pitfalls encountered during frozen section analysis. Recommendations regardingspecimenhandlingarealsoprovided. We hope that this monograph satisfies the need for practical guidelines for the handling and interpretation of resection spec- imens and facilitates communications between surgical patholo- gistsandoursurgicalcolleagues. NewYork,NY NicoleC.Panarelli RhondaK.Yantiss v Series Preface For over 100 years, the frozen section has been utilized as a tool fortherapiddiagnosisofspecimenswhileapatientisundergoing surgery, usually under general anesthesia, as a basis for making immediate treatment decisions. Frozen section diagnosis is often a challenge for the pathologist who must render a diagnosis that has crucial import for the patient in a minimal amount of time. In addition to the need for rapid recall of differential diagnoses, there are many pitfalls and artifacts that add to the risk of frozen section diagnosis that are not present with permanent sections of fully processed tissues that can be examined in a more leisurely fashion. Despite the century-long utilization of frozen sections, moststandardpathologytextbooks,bothgeneralandsubspecialty, largely ignore the topic of frozen sections. Few textbooks have ever focused exclusively on frozen section diagnosis and those textbooksthathavedonesoarenowout-of-dateandhavelimited illustrations. The Frozen Section Library Series is meant to provide conve- nient, user-friendly handbooks for each organ system to expedite use in the rushed frozen section situation. These books are small andlight-weight,copiouslycolorillustratedwithimagesofactual frozen sections, highlighting pitfalls, artifacts, and differential diagnosis.Theadvantagesofaseriesoforgan-specifichandbooks, in addition to the ease-of-use and manageable size, are that (1) a series allows more comprehensive coverage of more diagnoses, both common and rare, than a single volume that tries to high- lightalimitednumberofdiagnosesforeachorganand(2)aseries vii viii SeriesPreface allows more detailed insight by permitting experienced authori- tiestoemphasizethepeculiaritiesoffrozensectionforeachorgan system. Asahandbookforpracticingpathologists,thesebookswillbe indispensableaidstodiagnosisandavoidingdangersinoneofthe mostchallengingsituationsthatpathologistsencounter.Rapidcon- siderationofdifferentialdiagnosesandhowtoavoidtrapscaused by frozen section artifacts are emphasized in these handbooks. A series of concise, easy-to-use, well-illustrated handbooks alle- viatestheoftenfrustratingandtime-consuming,sometimesfutile, process of searching through bulky textbooks that are unlikely to illustrate or discuss pathologic diagnoses from the perspective of frozen sections in the first place. Tables and charts will provide guidance for differential diagnosis of various histologic patterns. Touchpreparations,whichareusedforsomeorganssuchascentral nervoussystemorthyroidmoreoftenthanothers,areappropriately emphasizedandillustratedaccordingtotheneedforeachspecific organ. This series is meant to benefit practicing surgical patholo- gists,bothcommunityandacademic,andpathologyresidentsand fellows; and also to provide valuable perspectives to surgeons, surgery residents, and fellows who must rely on frozen section diagnosisbytheirpathologists.Mostofall,wehopethatthisseries contributestotheimprovedcareofpatientswhorelyonthefrozen sectiontohelpguidetheirtreatment. PhilipT.Cagle SeriesEditor Contents 1 Intraoperative Evaluation of Colorectal SpecimensContainingCancer . . . . . . . . . . . . 1 2 IntraoperativeEvaluationforExtracolonic DiseaseinColonCancerPatients . . . . . . . . . . . 21 3 MetastasesandMimicsofColorectalCarcinoma . . 35 4 Non-epithelialTumorsoftheColorectum . . . . . . 59 5 Frozen Section Assessment of the Colorectum in the Pediatric Population . . . . . . . . . . . . . . . . . . . . . . . 77 6 FrozenSectionEvaluation oftheAppendix . . . . . . . . . . . . . . . . . . . . 85 7 FrozenSectionEvaluationofAnalDisease . . . . . 113 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 ix Chapter 1 Intraoperative Evaluation of Colorectal Specimens Containing Cancer Abstract Intraoperative assessment of colon cancer resec- tion specimens may influence immediate surgical management. Indications for evaluation include determining the depth of inva- sion,presenceofserosalpenetration,statusofmargins,andintact- ness of the mesorectum, when present. Pathologists may also be asked to identify residual carcinoma in neoadjuvantly treated patients, or document the presence of other lesions, such as ade- nomas, polypectomy sites, or underlying colitis. Estimating the depthofinvasionintothecolonicwallisbestachievedbymacro- scopic examination in combination with frozen section analysis, whereasdetectingserosalinvolvementmayrequiretouchorscrape preparationsoftheserosalsurface.Assessmentofmarginsismost challenging in rectal specimens, particularly when patients have receivedneoadjuvanttherapy. Keywords Colonic adenocarcinoma · Serosa · Margins · Mesorectum·Neoadjuvanttherapy Introduction Colorectal carcinoma is the most common carcinoma of the gastrointestinal tract, and more than 150,000 cases are diagnosed in the United States each year [1]. Surgical excision remains N.C.Panarelli,R.K.Yantiss,FrozenSectionLibrary:Appendix, 1 Colon,andAnus,FrozenSectionLibrary4,DOI10.1007/978-1-4419-6584-4_1, (cid:2)C SpringerScience+BusinessMedia,LLC2010 2 1 IntraoperativeEvaluationofColorectalSpecimens the mainstay of therapy, and pathologic assessment of resection specimens is critically important to the subsequent management of the patient. Pathologic evaluation is necessary to determine the extent of disease, which is the single most powerful predic- tor of outcome among colorectal cancer patients, and use of the TNMstagingsystemisnowstandardpracticeintheUnitedStates [2].Intraoperativeassessmentofcancer resectionspecimensmay influence immediate management, and indications for evaluation include determining (1) the depth of invasion, (2) presence of serosal penetration, (3) status of margins, and (4) intactness of the mesorectum; identifying residual carcinoma in neoadjuvantly treated patients; and documenting the presence of other lesions, suchaspolyps,dysplasiainchroniccolitis,andtattoosfromprior procedures. AssessingLocalExtentofColorectalCarcinoma The designations for pathologic tumor stage (pT) describe the deepest point of tumor penetration within the colonic wall [2]. Althoughfinalstageclassificationisdeferredtoreviewofperma- nentsections,pathologistsmaybeaskedtoprovideintraoperative staging information in some cases, such as assessment of appar- entlysuperficiallesions,whichmaybeamenabletolocalexcision. Gross assessment of tumor invasion is best achieved by serially sectioningatcloseintervals,whichusuallyallowsonetoestimate whether it is limited to the lamina propria, or penetrates the sub- mucosa,muscularispropria,orserosa.Invasivecarcinomasappear astan-white,ill-definedmassesthatobliteratenormaltissuelayers ofthecolonicwall,andthedeepestinvasionusuallyoccursinthe tumorepicenter[3](Fig.1.1). Theterm“carcinomainsitu”isgenerallyavoidedasadiagnos- tic category in colorectal neoplasia because it encompasses both intraepithelialcarcinomaandtumorsthatareinvasiveofthelamina propriabutconfinedtothemuscularismucosae.Mostpathologists prefer the term “adenoma with high-grade dysplasia” to describe a neoplastic proliferation confined to the basement membrane