Faculty, Staff and Student Publications

Language

English

Publication Date

9-23-2024

Journal

Head and Neck Pathology

DOI

10.1007/s12105-024-01690-x

PMID

39312022

PMCID

PMC11420419

PubMedCentral® Posted Date

9-23-2024

PubMedCentral® Full Text Version

Post-print

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.

Keywords

Adult, Aged, Female, Humans, Male, Middle Aged, Biomarkers, Tumor, Carcinoma, Squamous Cell, Chromosomal Proteins, Non-Histone, Oncogene Proteins, Oncogene Proteins, Fusion, Paranasal Sinus Neoplasms, Poly-ADP-Ribose Binding Proteins, Retrospective Studies, Squamous Cell Carcinoma of Head and Neck, DEK:AFF2 fusion, DEK, AFF2, Sinonasal papilloma, Sinonasal carcinoma, Immunohistochemistry, Fluorescence in situ hybridization

Published Open-Access

yes

Download

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.