An ecchondroma is a type of chondroma that is subperiosteal. Based upon location, a chondroma can be described as an enchondroma or ecchondroma. Extraskeletal chondroma is a cutaneous condition, a rare benign tumor of mature cartilage. The benign tumors are called chondroma, the malignant ones chondrosarcoma. A chondroma is a benign cartilaginous tumor, which is encapsulated with a lobular growing pattern.