Neoplasms and Neurovascular, Bone, and Extra-Articular Disorders
Primary neoplasms of joints, tendon sheaths, and bursae are rare. Most neoplasms are benign, arising from the synovium. These benign tumors include lipoma, hemangioma, and fibroma and tumor-like lesions such as ganglion, bursitis, and synovial cyst. Malignant tumors include primary tumors, such as synovial and bone sarcomas, and secondary involvement as manifestations of joint invasion by leukemia, lymphoma, and myeloma or metas-tasis. Neoplasms may present as back or neck pain.
Neurovascular disorders include the compression syndromes, such as those with peripheral entrapment (carpal tunnel syndrome), radiculopathy, and spinal stenosis. Raynaud’s phenomenon or disease and erythromelalgia (throbbing and burning pain often affecting the hands and feet) are also included in this category.
Bone and cartilage disorders include osteoporosis, osteomala-cia, hypertrophic osteoarthropathy, diffuse idiopathic skeletal hyperostosis, Paget’s disease, osteonecrosis, avascular necrosis, costochondritis, osteolysis or chondrolysis, and biomechanical or anatomic abnormalities. Notably, these conditions involve re-sorption, destruction, infection, or remodeling of bone.
Extra-articular rheumatism is a descriptive term for a group of conditions affecting structures other than the joints. Included are general and regional pain syndromes, low back pain and inter-vertebral disk disorders, tendonitis and bursitis, and ganglion cysts.