Relationship between dermoscopy and pathology in a case of clonal-type pigmented Bowen's disease: Observation with vertical-view dermoscopy.

Pigmented Bowen's disease (pBD) is a subtype of Bowen's disease, which presents clinically as a well-circumscribed, hyperpigmented plaque. Its clinical manifestations are not fully characterized, and differential diagnoses include various pigmented skin lesions. Dermoscopy could be useful for the diagnosis, although nothing has been reported on the dermoscopic features of clonal-type pBD. We herein report a first case of clonal-type pBD on the sole and its dermoscopic features. Dermoscopy showed brown to blue-gray dots/globules and focally anastomosing lines on the non-weight-bearing area, while the weight-bearing area had a brown to blue-gray fibrillar-like pattern. To investigate the relationship between dermoscopy and histopathology, we focused on the melanin distribution in the horny layer of the epidermis, and used vertical dermoscopy observation. We investigated the relationship between dermoscopy and pathology by melanin depth estimation using a color lightness value.