Osteochondroma: A cartilage-capped benign tumor that often appears as a stalk on the surface of bone. It is probably a developmental malformation rather than a true neoplasm and is usually found in the metaphysis of the distal femur, proximal tibia, or proximal humerus. Osteochondroma is the most common of benign bone tumors.Exostoses, Multiple Hereditary: Hereditary disorder transmitted by an autosomal dominant gene and characterized by multiple exostoses (multiple osteochondromas) near the ends of long bones. The genetic abnormality results in a defect in the osteoclastic activity at the metaphyseal ends of the bone during the remodeling process in childhood or early adolescence. The metaphyses develop benign, bony outgrowths often capped by cartilage. A small number undergo neoplastic transformation.Chondroma: A benign neoplasm derived from mesodermal cells that form cartilage. It may remain within the substance of a cartilage or bone (true chondroma or enchondroma) or may develop on the surface of a cartilage (ecchondroma or ecchondrosis). (Dorland, 27th ed; Stedman, 25th ed)Exostoses: Benign hypertrophy that projects outward from the surface of bone, often containing a cartilaginous component.Bone Neoplasms: Tumors or cancer located in bone tissue or specific BONES.Scapula: Also called the shoulder blade, it is a flat triangular bone, a pair of which form the back part of the shoulder girdle.Mandibular Neoplasms: Tumors or cancer of the MANDIBLE.Spinal NeoplasmsOsteochondromatosis: A condition marked by the presence of multiple osteochondromas. (Dorland, 27th ed)AxisRibs: A set of twelve curved bones which connect to the vertebral column posteriorly, and terminate anteriorly as costal cartilage. Together, they form a protective cage around the internal thoracic organs.Cervical Atlas: The first cervical vertebra.Spinal Cord Compression: Acute and chronic conditions characterized by external mechanical compression of the SPINAL CORD due to extramedullary neoplasm; EPIDURAL ABSCESS; SPINAL FRACTURES; bony deformities of the vertebral bodies; and other conditions. Clinical manifestations vary with the anatomic site of the lesion and may include localized pain, weakness, sensory loss, incontinence, and impotence.Chondrosarcoma: A slowly growing malignant neoplasm derived from cartilage cells, occurring most frequently in pelvic bones or near the ends of long bones, in middle-aged and old people. Most chondrosarcomas arise de novo, but some may develop in a preexisting benign cartilaginous lesion or in patients with ENCHONDROMATOSIS. (Stedman, 25th ed)N-Acetylglucosaminyltransferases: Enzymes that catalyze the transfer of N-acetylglucosamine from a nucleoside diphosphate N-acetylglucosamine to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.Neoplasms, Adipose Tissue: Neoplasms composed of fatty tissue or connective tissue made up of fat cells in a meshwork of areolar tissue. The concept does not refer to neoplasms located in adipose tissue.Mandibular Condyle: The posterior process on the ramus of the mandible composed of two parts: a superior part, the articular portion, and an inferior part, the condylar neck.Laminectomy: A surgical procedure that entails removing all (laminectomy) or part (laminotomy) of selected vertebral lamina to relieve pressure on the SPINAL CORD and/or SPINAL NERVE ROOTS. Vertebral lamina is the thin flattened posterior wall of vertebral arch that forms the vertebral foramen through which pass the spinal cord and nerve roots.