Definition: A papilloma is a small, harmless tumor that can occur on a bird's skin. Much like warts, they are caused by a viral infection, and can be crusty or have slight protrusions. Most papillomas require no treatment unless the bird is causing trauma to the area through plucking.
Common Misspellings: pappiloma
A papilloma will usually resolve itself eventually, provided that the bird ignores it.