Bowen Disease. Bowen disease is also called squamous cell carcinoma in situ.. It is a type of skin cancer that spreads outward on the surface of the skin. By contrast, invasive squamous cell carcinomas can grow inward and spread to the interior of the body.owen Disease. Bowen disease is also called squamous cell carcinoma in situ.. It is a type of skin cancer that spreads outward on the surface of the skin. By contrast, invasive squamous cell carcinomas can grow inward and spread to the interior of the body.