 The informal term "canker sore" is sometimes used, mainly in North America, either to describe this condition generally, or to refer to the individual ulcers of this condition, or mouth ulcers of any cause unrelated to this condition. The origin of the word "canker" is thought to have been influenced by Latin, Old English, Middle English and Old North French. In Latin, cancer translates to "malignant tumor" or literally "crab" (related to the likening of sectioned tumors to the limbs of a crab). The closely related word in Middle English and Old North French, chancre, now more usually applied to syphilis, is also thought to be involved. Despite this etymology, aphthous stomatitis is not a form of cancer but rather entirely benign.
