chondromyxofibroma /kon′drōmik′sōfībrō″mə/ [Gk, chondros + myxa, mucus; L, fibra, fiber, oma, tumor] , a benign tumor that develops from cartilage-forming connective tissue. The lesion, typically a firm, grayish-white mass, tends to occur in the knee and small bones of the foot and may be confused with chondrosarcoma. Also called chondromyxoid fibroma.