Related Experiment Video
Updated: Nov 4, 2025
Identification of OTX1 and OTX2 As Two Possible Molecular Markers for Sinonasal Carcinomas and Olfactory Neuroblastomas
Published on: February 28, 2019
DEK-AFF2 Carcinoma of the Sinonasal Region and Skull Base: Detailed Clinicopathologic Characterization of a
Lisa M Rooper1,2, Abbas Agaimy3, Brendan C Dickson4,5
1Departments of Pathology.
Abstract:
A novel DEK-AFF2 fusion was recently reported in 4 nonkeratinizing squamous cell carcinomas of the sinonasal region and skull base, including 1 with exceptional response to immunotherapy, but it is not yet clear if this rearrangement defines a unique clinicopathologic category or represents a rare event. This study aims to characterize a larger cohort of carcinomas with DEK-AFF2 fusions to assess whether they truly constitute a distinctive entity. Among 27 sinonasal and skull base nonkeratinizing squamous cell carcinoma that were negative for human papillomavirus and Epstein-Barr virus, RNA sequencing identified DEK-AFF2 fusions in 13 cases (48%). Nine were centered in the nasal cavity, 2 in the middle ear/temporal bone, 1 in the nasopharynx, and 1 in the orbit. These tumors displayed recurrent histologic features including (1) complex endophytic and exophytic, frequently papilloma-like growth, (2) transitional epithelium with eosinophilic to amphophilic cytoplasm, (3) absent or minimal keratinization with occasional compact keratin pearls, (4) monotonous nuclei, and (5) prominent tumor-infiltrating neutrophils or stromal lymphocytes. This appearance not only overlaps with high-grade basaloid sinonasal carcinomas but also with benign papillomas and tumors reported as low-grade papillary Schneiderian carcinoma. However, DEK-AFF2 carcinomas showed frequent local recurrence, cervical lymph node metastases, and distant metastasis with 2 deaths from disease, confirming they are aggressive malignancies despite relatively bland histology. Overall, the distinctive molecular, histologic, and clinical features of DEK-AFF2 carcinomas suggest they represent a unique entity in the sinonasal region. This tumor merits increased pathologic recognition to better understand its prognostic and therapeutic implications.
Insights
A newly identified DEK-AFF2 fusion defines a unique aggressive cancer in the sinonasal region. This discovery highlights a distinct tumor entity with specific histologic and clinical features, crucial for better diagnosis and treatment.
Area of Science:
- Oncology
- Pathology
- Genetics
Background:
- A novel DEK-AFF2 fusion was recently identified in sinonasal and skull base nonkeratinizing squamous cell carcinomas.
- It remains unclear if this genetic rearrangement represents a rare event or a distinct clinicopathologic entity.
Purpose of the Study:
- To characterize a larger cohort of carcinomas with DEK-AFF2 fusions.
- To assess if these fusions define a distinctive tumor entity in the sinonasal region.
Main Methods:
- RNA sequencing was performed on 27 sinonasal and skull base nonkeratinizing squamous cell carcinomas negative for HPV and EBV.
- Histologic features and clinical outcomes were analyzed for tumors with identified DEK-AFF2 fusions.
Main Results:
- DEK-AFF2 fusions were identified in 13 out of 27 cases (48%).
- Recurrent histologic features included papillary-like growth, transitional epithelium, minimal keratinization, monotonous nuclei, and prominent inflammatory infiltrates.
- These tumors demonstrated aggressive behavior with frequent recurrence, metastasis, and disease-related deaths, despite relatively bland histology.
Conclusions:
- The distinctive molecular, histologic, and clinical features of DEK-AFF2 carcinomas suggest they represent a unique entity.
- Increased pathologic recognition is needed to understand the prognostic and therapeutic implications of this tumor.
