The presence of a neoplasm in bone is manifested in a variety of ways. Pain and localized swelling or pathologic fracture are the most frequent presenting complaints, but rarely is a bone tumor discovered as an incidental finding on radiographic…
Myositis Ossificans Definition Myositis ossificans is a reactive, self-limiting condition characterized by prominent heterotopic ossification. It predominantly occurs deep in soft tissue, and it undergoes zonal maturation. If the lesion is located in the vicinity of bone (i.e., involves the…
Modern understanding of rachitic syndromes, originally referred to as vitamin D-resistant rickets, is based on the identification of a novel phosphate-regulating homeostatic system and its underlying diverse genetic background. Essential to this understanding were discoveries of two mutated genes involved…
Sclerosing bone lesions represent a unique group of dysplastic anomalies with a wide range of clinical presentations, radiographic characteristics, and genetic backgrounds. They can be separated into two major groups with hereditary and nonhereditary clinical presentations. A comprehensive description of…
Synovial Chondromatosis Definition Synovial chondromatosis is a metaplastic condition involving articular or tendon sheath synovial membranes in which multiple nodules of cartilage are produced. Many of the nodules subsequently become detached from the synovial membrane and float in the joint.…
Bone is one of the most common anatomic sites for metastases, along with the lungs and liver, and metastases are the most commonly diagnosed neoplasms encountered in the skeleton. Although most metastases encountered in the adult skeleton are either carcinoma…
In evolutionary biology, the notochord or chorda dorsalis is typically discussed as a prototypic internal skeleton of prevertebrate animals. In vertebrates, the notochord exists transiently and in addition to providing structural integrity to the embryo, it secretes factors that are…
An epithelial neoplasm originating in the long bones of the skeleton, referred to as adamantinoma, which almost exclusively affects the tibia and fibula, and its relationship to a coexisting peculiar fibroosseus lesion, has been intriguing both pathologists and clinicians for…
Lipoma Definition Lipoma is a rare primary tumor of bone composed of mature adipose tissue. Lipomas involving bone are divided into three types: intramedullary (intraosseous), intracortical/subperiosteal, and parosteal. Lipomas involving synovial tissue are described in Chapter 20 . Incidence and…
Cystic lesions of bone represent a heterogeneous group of entities in which the common feature is de novo formation of unilocular or multilocular cavities filled with blood, serous fluid, mucinous content, or keratin debris. Secondary cystic changes in preexisting conditions,…