Added value of <scp>LC</scp> ‐ <scp>OCT</scp> in equivocal melanocytic lesions: A prospective study

BACKGROUND: Dermoscopy achieves high sensitivity for melanoma detection but remains limited by low specificity in equivocal melanocytic lesions, leading to unnecessary excisions. Line-field confocal optical coherence tomography (LC-OCT) is an emerging non-invasive imaging technique combining vertical and horizontal high-resolution imaging, with potential to improve diagnostic accuracy in daily practice. OBJECTIVES: To evaluate the added diagnostic value of LC-OCT when used as a second-line triage tool after clinical and dermoscopic assessment of equivocal melanocytic lesions in a real-world high-risk setting. METHODS: This prospective diagnostic accuracy study included consecutive adult patients presenting with clinically and/or dermoscopically equivocal melanocytic lesions in a tertiary referral centre. All lesions underwent clinical and dermoscopic examination followed by LC-OCT imaging. Reflectance confocal microscopy-guided management decisions independently of LC-OCT. Histopathology served as the reference standard for excised lesions, while stability during digital dermoscopic follow-up was considered indicative of benignity. Diagnostic performance of dermoscopy alone and dermoscopy combined with LC-OCT was assessed using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy. RESULTS: A total of 227 lesions from 178 patients were included, of which 76 (33.5%) were melanomas. Dermoscopy alone showed high sensitivity (96.1%) but low specificity (32.5%). The addition of LC-OCT maintained high sensitivity (94.7%) while significantly improving specificity (65.6%) and overall accuracy (75.3%). PPV increased from 41.7% to 58.1%, whereas NPV remained high (≥94%). Among lesions managed by follow-up, two melanomas were diagnosed after interval changes. No advanced invasive melanomas were missed with the combined approach. CONCLUSIONS: In a high-risk real-world setting, LC-OCT significantly improves the specificity and overall diagnostic accuracy of dermoscopy for equivocal melanocytic lesions while maintaining high sensitivity. As a second-line triage tool, LC-OCT may reduce unnecessary excisions and support safer non-invasive management strategies in melanoma surveillance.