Line-Field Confocal Optical Coherence Tomography for the Evaluation of Pigmented Skin Lesions of the Genital Area

<b>Background/Objectives:</b> Pigmented lesions of the genital area are of commonly occurrence, with population-based incidence estimated around 10-20%. Historically, invasive biopsy or surgical removal were recommended to obtain a definite diagnosis. Line-field confocal optical coherence tomography (LC-OCT) is a novel multimodality imaging tool, able to reproduce a "virtual biopsy" of skin lesions, offering vertical, horizontal, and three-dimensional (3D) imaging down to the mid-dermis with high-resolution real-time visualization. The aims of the study were (i) to describe the LC-OCT features in a series of benign and malignant pigmented genital lesions (PGLs), (ii) to investigate the impact of LC-OCT on the diagnostic accuracy, (iii) and to estimate the diagnostic concordance between LC-OCT and histopathology. <b>Methods:</b> This was a retrospective, cross-sectional study including histologically confirmed PGL investigated with LC-OCT over 2 years. Descriptive statistics were calculated for continuous and categorical variables. Diagnostic accuracy of LC-OCT and dermoscopy was compared, and the LC-OCT-histopathology diagnostic concordance was estimated. <b>Results:</b> A total of 96 PGLs were analyzed in 23 male and 57 female patients. Pathologic reporting consisted of 56 melanoses, 21 nevi (15 compound nevi and 6 atypical genital nevi), 10 melanomas, and 9 angiokeratomas. LC-OCT obtained higher diagnostic accuracy rather than dermoscopy; diagnostic concordance LC-OCT/histopathology was 91% (87/96; 95% CI 83.7-95.3). Melanoses were characterized by a continuous undulated junction. Common genital nevi were identified by the presence of regular dense nests, while dischoesive nests were seen in atypical genital nevi. Features of epidermal disarray with pagetoid cells, junctional atypia, and discohesive nests were observed in melanoma. Angiokeratomas showed the presence of dark vascular lacunae. <b>Conclusions:</b> Providing in vivo key clues with a resolution close to classic histopathology, LC-OCT may have a valuable role in the clinical management of PGLs, particularly when lesions involve large areas or are multiple in number.