Sara E Amin, James S Lewis, Julia A Bridge, Jen-Fan Hang, Udit Naik, Justin A Bishop, Karan Saluja
{"title":"DEK::AFF2 Fusion-Associated Squamous Cell Carcinoma: A Case Series with Literature Review on an Emerging and Challenging Entity.","authors":"Sara E Amin, James S Lewis, Julia A Bridge, Jen-Fan Hang, Udit Naik, Justin A Bishop, Karan Saluja","doi":"10.1007/s12105-024-01690-x","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>DEK::AFF2 fusion-associated squamous cell carcinoma (DEK::AFF2 SCC), also reported in the literature as low-grade papillary sinonasal (Schneiderian) carcinoma (LGPSC), is a rare, primarily bland-appearing, but locally aggressive neoplasm. Morphologically, these tumors can closely resemble sinonasal papilloma (SP), especially on small or limited biopsy, often leading to misdiagnosis. DEK::AFF2 SCC is devoid of the underlying mutually exclusive EGFR or KRAS driver mutations of SP, suggesting it may represent a distinct unique entity.</p><p><strong>Methods: </strong>In this study, we conducted a retrospective search of \"unusual\" SP reported either as atypical, dysplastic, or suspicious for malignant transformation at our institution in the last 13 years (2010-2023), to identify potential cases of DEK::AFF2 SCC.</p><p><strong>Results: </strong>Of the 201 SP cases during this time period, 30 \"unusual\" SP cases were identified. On morphologic review of these 30 cases, 6 were worrisome for DEK::AFF2 SCC and were selected for AFF2 immunohistochemical stain (IHC), of which 3 cases were positive. All 3 AFF2 IHC positive cases were also positive for DEK::AFF2 fusion by fluorescence in situ hybridization (FISH), thereby, confirming IHC results.</p><p><strong>Conclusions: </strong>This study highlights that AFF2 IHC can be an invaluable surrogate marker to FISH in identifying DEK::AFF2 SCC in challenging cases to avoid misdiagnosis. Detailed clinical and pathologic data were collected to gain a better understanding of this emerging challenging entity. A literature review was performed to enrich our knowledge of DEK::AFF2 SCC.</p>","PeriodicalId":47972,"journal":{"name":"Head & Neck Pathology","volume":null,"pages":null},"PeriodicalIF":3.2000,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11420419/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Head & Neck Pathology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/s12105-024-01690-x","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PATHOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: DEK::AFF2 fusion-associated squamous cell carcinoma (DEK::AFF2 SCC), also reported in the literature as low-grade papillary sinonasal (Schneiderian) carcinoma (LGPSC), is a rare, primarily bland-appearing, but locally aggressive neoplasm. Morphologically, these tumors can closely resemble sinonasal papilloma (SP), especially on small or limited biopsy, often leading to misdiagnosis. DEK::AFF2 SCC is devoid of the underlying mutually exclusive EGFR or KRAS driver mutations of SP, suggesting it may represent a distinct unique entity.
Methods: In this study, we conducted a retrospective search of "unusual" SP reported either as atypical, dysplastic, or suspicious for malignant transformation at our institution in the last 13 years (2010-2023), to identify potential cases of DEK::AFF2 SCC.
Results: Of the 201 SP cases during this time period, 30 "unusual" SP cases were identified. On morphologic review of these 30 cases, 6 were worrisome for DEK::AFF2 SCC and were selected for AFF2 immunohistochemical stain (IHC), of which 3 cases were positive. All 3 AFF2 IHC positive cases were also positive for DEK::AFF2 fusion by fluorescence in situ hybridization (FISH), thereby, confirming IHC results.
Conclusions: This study highlights that AFF2 IHC can be an invaluable surrogate marker to FISH in identifying DEK::AFF2 SCC in challenging cases to avoid misdiagnosis. Detailed clinical and pathologic data were collected to gain a better understanding of this emerging challenging entity. A literature review was performed to enrich our knowledge of DEK::AFF2 SCC.
期刊介绍:
Head & Neck Pathology presents scholarly papers, reviews and symposia that cover the spectrum of human surgical pathology within the anatomic zones of the oral cavity, sinonasal tract, larynx, hypopharynx, salivary gland, ear and temporal bone, and neck.
The journal publishes rapid developments in new diagnostic criteria, intraoperative consultation, immunohistochemical studies, molecular techniques, genetic analyses, diagnostic aids, experimental pathology, cytology, radiographic imaging, and application of uniform terminology to allow practitioners to continue to maintain and expand their knowledge in the subspecialty of head and neck pathology. Coverage of practical application to daily clinical practice is supported with proceedings and symposia from international societies and academies devoted to this field.
Single-blind peer review
The journal follows a single-blind review procedure, where the reviewers are aware of the names and affiliations of the authors, but the reviewer reports provided to authors are anonymous. Single-blind peer review is the traditional model of peer review that many reviewers are comfortable with, and it facilitates a dispassionate critique of a manuscript.