Also known as Hereditary multiple exotoses.
Autosomal dominant disease.
Associated with inactivation of tumor suppressor genes located on chromosomes 8,11, and 19, locus EXT1, EXT2 and EXT3, respectively.
Radiographic studies demonstrate cortical and medullary continuity between the osteochondroma and parent bone.
Surgical resection of exotosis is required for symptomatic patients.
Malignant conversion to chondrsarcomas occurs in 1% of solitary lesions and 3-5% of hereditary cases.
Malignant transformation suggested by increasing bone pain or enlarging bone tumors, because osteochondromas do not enlarge during adulthood.
Malignant transformation suggested by radiographic bone border irregularities and adjacent tissue destruction.