Dermoscopic Features of Pigmented Bowen Disease in Phototype IV Patients

Introduction: Research on the dermoscopic features of pigmented Bowen disease (pBD) in individuals with phototype IV skin is limited and consists primarily of case reports or small studies. Objectives: We sought to describe the clinical and dermoscopic characteristics of 21 cases of pBD in a skin phototype IV population. Methods: We conducted a multicenter retrospective analysis of 21 histopathologically confirmed cases of pBD under the auspices of the Dermoscopy Chapter of the Ibero-Latin American College of Dermatology (CILAD). Results: A total of 21 pBD cases in phototype IV patients (57% male, mean age 63.1 years) were analyzed. Lesions were most frequently located on the upper extremities and head and neck area (29% and 24%, respectively) and exhibited brown (90.5%) and pink (90.5%) coloration, with a higher prevalence of gray, black, and blue compared to lighter phototypes. Structureless areas (90.5%) and pigmented dots in a linear arrangement (71.4%) were the most frequent dermoscopic findings. Non-specific dermoscopic findings were observed in 23.8% (N=5) of cases. Conclusion: PBD in phototype IV presents with a distinct dermoscopic pattern, including a higher proportion black and blue colors and fewer vascular structures than observed in lighter phototypes. The most prominent dermoscopic findings were structureless areas and pigmented dots, either in a central or peripheral linear arrangement; however, in a quarter of the cases, no specific clue was observed. These findings emphasize the need for tailored diagnostic approaches and the importance of biopsy when specific dermoscopic features are absent.