Bowen's disease, also known as squamous cell carcinoma in situ, is a type of skin disorder characterised by the presence of precancerous or intra-epidermal squamous cell carcinoma. It was named after John T. Bowen, the dermatologist who first described the condition in 1912. Bowen's disease primarily affects the outermost layer of the skin (epidermis) and is considered a form of non-invasive skin cancer. Bowen's disease most commonly occurs on sun-exposed areas of the skin, such as the face, neck, head, hands and forearms. However, it can also occur in areas not exposed to the sun. In this episode, Dr Roger Henderson looks at how best to diagnose and manage Bowen’s disease, as well as looking at its prognosis and prevention.