Synovial-based lesions encompass both reactive and neoplastic processes. Although any joint may be affected, the most common site of disease is the knee. Pathologic changes in the small joints of the fingers are typically due to rheumatoid disease or localized…
The term crystalline arthropathy is a general term that refers to the presence of crystalline deposits in or around joints, sometimes within tendon sheaths and bursae as well. Essentially three crystalline substances may be found in articular and periarticular tissues.…
Osteoarthritis Definition and Synonyms Bone morphogenetic protein (BMP): a member of a superfamily of proteins that promotes the formation of bone and the skeleton Collagen IX: a fibrous protein that is a heterodimeric molecule expressed mainly in cartilage Collagen X:…
The notochord is a rod-shaped structure that forms during the third week of gestation and organizes formation of the axial skeleton. As vertebral bodies undergo ossification, the notochord becomes fragmented, and by the second month of development, notochordal tissue is…
Overview Metastases to bone of tumors from nonosseous primary sites account for the largest percentage of bone tumors. The host bone responds either by osseous resorption (osteolytic), osseous formation (osteoblastic), or often both processes. This chapter will cover the clinical…
Benign “Soft Tissue” Tumors Primary in Bone Schwannoma Definition and Synonyms Schwannoma, also known as neurilemmoma and neurinoma, is a benign nerve sheath tumor that occurs primarily in soft tissue but can also occur primarily within bone or secondarily involve…
Cystic lesions of bone comprise a diverse number of entities, including simple or unicameral bone cyst, aneurysmal bone cyst (ABC), epidermal cyst, and intraosseous ganglion. Simple bone cysts are typically lesions of boys in the long bones and are relatively…
Permeative lesions involving the bone represent many different disease processes and radiographically may mimic one another. The permeative lesions discussed in this chapter represent a diverse group that include benign tumors, malignant tumors, a variety of histiocytic disorders, hematolymphoid-derived tumors…
Vascular tumors of bone are defined as a neoplastic proliferation of endothelial cells that are biologically benign or malignant. This is a heterogeneous group of tumors; it includes a wide variety of different clinicopathologic entities whose biological potential ranges from…
Fibro-osseous Lesions Fibrous Dysplasia Overview Fibrous dysplasia of bone was historically thought to be a developmental anomaly of fibrous tissue and bone but is now known to be secondary to defined mutations in the GNAS gene. Histologically, the osseous component…