Differentiating Sinonasal Tumor Entities with Fluorescein-Enhanced Confocal Laser Endomicroscopy: A Step Forward in Precision Diagnostics

<b>Background/Objectives</b>: Sinonasal malignancies are rare and highly diverse cancers that pose significant diagnostic challenges due to their variable histological features and complex anatomical locations. Accurate diagnosis is critical for guiding treatment, yet conventional methods often require multiple biopsies. This study aimed to evaluate the potential of confocal laser endomicroscopy (CLE) for real-time imaging of sinonasal tumors to characterize specific features of different entities and improve diagnostic precision. <b>Methods</b>: Ten patients with various sinonasal malignancies, including squamous cell carcinoma, adenocarcinoma, sinonasal undifferentiated carcinoma, olfactory neuroblastoma, sinonasal mucosal melanoma, and endonasal lymphoma, were examined using CLE during diagnostic endoscopy. CLE images were compared descriptively with histopathological cross-sections to identify unique imaging patterns for each tumor type. <b>Results</b>: CLE was feasible across all cases, with high-quality images obtained despite anatomical challenges in some cases. Characteristic features, such as vascular clusters in undifferentiated carcinoma, mucin-filled bubbles in adenocarcinoma, and small round cells in neuroblastoma, were identified and corresponded well with histopathological findings. CLE also helped guide biopsies by revealing areas with diagnostic relevance. <b>Conclusions</b>: CLE demonstrates promise as an adjunct diagnostic tool in sinonasal malignancies, offering real-time imaging that correlates with histopathological findings and aids in targeted biopsies. While this study provides preliminary insights into the utility of CLE, further research with larger cohorts and statistical validation is necessary to establish its diagnostic reliability and broader clinical application.