Typically, Bowen disease appears as a slow-growing, persistent reddish-brown patch or plaque of dry, scaly skin. These lesions may be flat or slightly raised. The lesions are normally not associated with any symptoms, but, occasionally, can itch, ooze pus (if infected), bleed or become crusted and/or tender. In some cases, the lesions may be warty (verrucous), split open (fissured) or, less often, darkly colored (pigmented). In most cases, there is only one lesion, but in approximately 10-20 percent of individuals multiple lesions may develop usually in more than one area of the body.
Although Bowen disease occurs most often on sun exposed areas of the skin, it can develop anywhere on the body, even areas of the skin that are not usually exposed to the sun. The disorder most often develops on the lower legs. Less commonly, the head, neck, palms, soles and genitals can be affected. The lesions can measure anywhere from a few millimeters to a few centimeters.
Individuals with Bowen disease are at risk of developing skin cancer. The risk is estimated to be less than 10 percent, but can be higher in individuals with a compromised immune system. Early signs of cancerous transformation in Bowen disease include the development of a fleshy nodule or bump in a skin lesion. This nodule may be tender and bleed easily. Ulceration or hardening (induration) of a skin lesion also indicates malignant transformation.
Bowen disease is classified as an early, noninvasive form of squamous cell carcinoma, a type of skin cancer that most often occurs on sun damage areas of the skin. Squamous cell carcinoma is the second most common form of skin cancer.