A case of clear-cell Bowen's disease which may have developed following cryotherapy

Bowen's disease is a kind of squamous cell carcinoma in situ. In some cases, a pagetoid growth pattern can be observed with cytologically atypical clear cells arranged singly or in nests. The differential diagnosis of clear-cell Bowen's disease includes primarily Paget's disease and malignant melanoma in situ. A 66-year-old man presented with intermittently painful, solitary, well-demarcated, annular, erythematous, scaly plaque on the left fourth finger for 7 months. This had been treated by cryotherapy 8 months earlier, following the diagnosis of Bowen's disease. The skin biopsy specimen revealed nests of atypical clear cells in upper layer of the epidermis in addition to typical features of Bowen's disease. We, herein, report a rare case of clear-cell Bowen's disease, which is thought to have developed after cryotherapy.