Bowen's Disease, sometimes simply known as Bowen's among dermatologists, most often looks like a bright-red or pink scaly patch, located on previously or presently sun-exposed skin.

Many doctors and authorities regard Bowen's as a form of squamous cell carcinoma; though some regard it as a precancer. The cells in Bowen's are extremely unusual or atypical under the microscope and in many cases look worse under the microscope than the cells of many outright and invading squamous-cell carcinomas. The degree of atypia (strangeness, unusualness) seen under the microscope best tells how cells may behave should they invade another portion of the body.