Treatment of Bowen's disease with topical dinitrochlorobenzene and 5‐fluorouracil

“Bowen's disease” is a clinical and histologic diagnosis describing the lesions (single or multiple) of cutaneous in situ squamous cell carcinoma. The case of a 54‐year‐old man with 60 such intra‐epidermal carcinomas, and a history of arsenic ingestion, is presented. The patient was sensitized to dinitrochlorobenzene (DNCB), and his lesions were treated with a topical DNCB preparation. All lesions disappeared completely (demonstrated by biopsy of several sites) except for a large (12 × 7 cm) tumor on the flank which partially resolved. Total regression of this lesion was achieved by adding topical 5‐fluorouracil (5‐FU) therapy. This case demonstrates that the inflammatory reaction induced by DNCB (as evidenced by erythema and by a dense inflammatory cell infiltrate in biopsied areas of treated lesions) can lead to regression of extensive in situ epidermoid carcinoma, and that combined therapy with DNCB and 5‐FU can be more effective than DNCB alone. Both agents in appropriate concentrations led to selective destruction of neoplastic tissue with no effect on adjacent normal skin. No systemic toxicity was observed.