Medically reviewed by Edmund Khoo, DDS A bump on the roof of the mouth can have a number of causes, including canker sores, fungal infections, or bony growths. The bump may be painless or sore.

While rare, a bump on the roof of your mouth could be a sign of oral cancer, especially if it lingers or grows. This type of cancer may appear as a persistent lump or sore that doesn't heal.

Rowan Steiner says 5 doctors examined the blue mass in her son's mouth before a specialist used a dental tool to pry it off.