Dermoscopic Features of Pigmented Bowen Disease in Phototype IV Patients

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.

We sought to describe the clinical and dermoscopic characteristics of 21 cases of pBD in a skin phototype IV population.

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).

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.

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.