an early on phase of skin cancer that develops from squamous cells (the level, scale-like cells into the external level of the skin). The characteristic is a persistent, modern, somewhat raised, red, scaly, or crusted plaque that could occur anywhere on the skin area or on mucosal areas, eg in the mouth. Under a microscope, atypical squamous cells are noticed having proliferated through the entire thickness of epidermis (the external layer of your skin) but not past. Squamous mobile carcinoma in situ is often brought on by sun visibility, but could be from prolonged experience of arsenic. Also referred to as Bowen infection.