myxochondroma noun1 •An unusual benign tumor of cartilaginous skeletal tissues (bones, ligaments, and tendons) that is a type of chondroma with myxoid (mucoid) degeneration of chondrocytes.Microscopically the tumour is a myxochondroma, with mucoid degeneration affecting the cartilage cells. — 1929 formsmyxochondromas · myxochondromata