The Role of Imaging Techniques in Pigmented Bowen Disease and Lentigo Maligna of the Head and Neck: A Comparative Dermoscopic and Reflectance Confocal Microscopy Study

Pigmented Bowen disease (pBD) may closely mimic lentigo maligna (LM) both clinically and dermoscopically. Accurate differentiation between these entities is clinically crucial, as misclassification may lead to overtreatment or undertreatment. Noninvasive imaging techniques, including dermoscopy and reflectance confocal microscopy (RCM), have improved diagnostic accuracy, but direct comparative data between pBD and LM remain limited. This observational cohort study included 10 consecutive cases of pBD and 10 consecutive cases of LM diagnosed between January and July 2024 at a tertiary referral dermatologic oncology center. All lesions were located on the head and neck and underwent dermoscopic and/or RCM evaluation prior to definitive diagnosis. Epidemiological, clinical, dermoscopic, and confocal features were retrospectively analyzed and compared between groups. The median age at diagnosis did not differ significantly between pBD and LM (64 vs. 56 years; p = 0.29). Surface scale was significantly more frequent in pBD (70.0% vs. 10.0%; p = 0.020). Dermoscopy showed substantial overlap between groups, although follicular-centric gray patterns were more commonly observed in LM. RCM demonstrated the highest discriminatory value: disarrayed keratinocytes were present in all pBD lesions compared with 30.0% of LM lesions (p = 0.003), while pagetoid cells were significantly more frequent in LM (70.0% vs. 10.0%; p = 0.020). In conclusion, a multimodal imaging approach integrating dermoscopy and RCM improves diagnostic discrimination between pBD and LM. RCM provides decisive cellular-level information and represents a valuable second-level tool in the evaluation of equivocal pigmented lesions.