Bowen Disease · What Is It, Symptoms, Treatment, and More

Bowen disease is an early stage of squamous cell carcinoma, a form of skin cancer that involves a group of cells called squamous keratinocytes. 

Squamous cell carcinoma is the second most common type of skin cancer, after basal cell carcinoma. It can be divided into three stages: actinic keratosis, Bowen disease, and invasive squamous cell carcinoma. Actinic keratosis is a precancerous lesion where keratinocytes are damaged by radiation and begin to overproduce keratin. Over time, these damaged keratinocytes can become malignant and develop into squamous cell carcinoma. On the other hand, Bowen disease is considered to be a form of squamous cell carcinoma in situ because cancer cells can be found in the epidermis but have not yet invaded the basement membrane. As squamous cell carcinoma becomes more invasive, it can breach the basement membrane and access blood vessels and lymphatics; from there, it can metastasize to other parts of the body.  

Diagnosis of Bowen disease starts with skin examination assessing the characteristics of the lesion as well as a detailed history of the current skin lesion, time of onset, duration, location, and evolution. Dermoscopy typically follows, which is a noninvasive technique that uses a magnifying lens to visualize skin structures that would otherwise not be visible to the naked eye. If Bowen disease or another form of skin cancer is suspected, a tissue biopsy including the subcutaneous tissue may be performed to confirm the diagnosis. On skin biopsy, Bowen disease reveals atypical keratinocytes that involve the full thickness of the epidermis without infiltration into the dermis.  

In the anogenital area, Bowen disease should be distinguished from bowenoid papulosis, a premalignant lesion that presents as solitary or multiple small pink, brown, or violaceous papules that can resemble genital warts. Bowenoid papulosis is considered a sexually transmitted infection caused by high-risk human papillomavirus, particularly HPV 16. 

There are several treatment options for Bowen disease, both surgical and non-surgical. Surgery is the preferred treatment for Bowen disease and squamous cell carcinoma. Options include standard surgical excision and Mohs surgery, a very precise technique used on high-risk sites, such as the face or genitalia.  

Non-surgical treatments may be performed in selected cases and include curettage and electrodesiccation, cryotherapy, photodynamic therapy, and topical medications. Curettage and electrodesiccation is one of the simplest, safest, and most effective treatments for Bowen disease; however, it can only be performed on small, solitary lesions that have a low risk of progression to invasive disease. It typically involves scraping out the lesion with a curette and then applying light cautery to stop the bleeding.  

Another alternative is cryotherapy, where the tumor is frozen off with liquid nitrogen. This technique is typically used in individuals with multiple superficial lesions where confirmation of the diagnosis has been obtained via a prior biopsy. Side effects of the procedure can include local discomfort and pain, ulceration, and long healing times, as well as hyper- or hypopigmentation, so it is preferred in areas where cosmesis is not a major concern.  

Next, photodynamic therapy is a treatment that uses photosensitizing agents that are activated with light to treat cancer cells. Finally, topical therapy with fluorouracil or imiquimod creams may be used to treat Bowen disease, especially for lesions that are larger than 3 centimeters in diameter and in situations where healing after the other treatment options would be compromised (e.g., lesions that involve the lower legs in older individuals or those with venous stasis disease). 

After successful treatment, individuals should follow up with their clinician to detect any recurrences. Follow-up time may vary between 3 to 6 months to a year, depending on the chosen treatment and the characteristics of the lesion. Because UV radiation is the main risk factor for Bowen disease and skin cancer, individuals may be advised to avoid or minimize sun exposure, use broad spectrum sunscreens daily, and wear protective clothing to protect the skin from the sun.