Cartilage choristoma (soft tissue chondroma): a rare presentation in the lower lip.

Cartilage choristoma (soft tissue chondroma) is an ectopic cartilaginous tissue that is rarely found in oral mucosa. Awareness of such disease entity will guide proper diagnosis and treatment. A case of cartilage choristoma occurring in the lower lip of an 8-year-old child is reported. Potential pathogenetic mechanism and the histologic features of this unusual condition are further discussed.