Arsenic keratosis and pigmentation accompanied by multiple Bowen's disease and genitourinary cancer in a psoriasis patient.

We report a case of arsenic keratosis and pigmentation accompained by multiple Bowen's disease and genitourinary cancer in a 64-year-old man. He was a psoriasis patient with a history of herbal medication for about thirty years. He showed multiple hyperkeratotic plaques on the bilateral palms, soles, and multiple, brownish, scaly, elevated papules on the back in addition to diffuse hyperpigmentation. Biopsy confirmed arsenic keratosis and Bowen's disease. Transitional cell carcinoma was also detected on his ureter and bladder during follow-up. The skin lesions were treated with topical 5-fluorouracil, etretinate, and excision with improvement.