Musculoskeletal Key

Diagnostic Studies. The lesion commonly develops in the metaphysis of the distal femur or distal tibia and is eccentrically located, usually within or adjacent to the cortex. Radiographs reveal a…

Monostotic lesions generally occur in the proximal femur, proximal tibia, mandible, and ribs. Polyostotic disease, which usually presents earlier, may be unilateral or widespread, affecting long bones, hands, feet, facial…

Diagnostic Studies. The radiographic hallmark is an epiphyseal radiolucent lesion with fine punctate calcifications suggestive of a cartilaginous lesion. The tumor is usually bordered by a well-defined margin of reactive…

The initial clinical sign is a hard, painless mass fixed on the bone. Symptoms, when present, are usually due to irritation of the overlying soft tissues that may or may…

Diagnostic Studies. Periosteal chondromas appear on radiographs as a radiolucent oval or oblong defect visualized as a crater-like deformity of the periphery of the cortex. The lesion is underlined by…

Enchondromas can occur anywhere in the skeleton. In very rare cases, a benign enchondroma undergoes malignant transformation into secondary chondrosarcoma (see Plate 6-17). However, aggressive appearing lesions in the hands…

Diagnostic Studies. Plain radiographs show a relatively radiolucent, bone-forming (osteoblastic) lesion that is osteolytic and often has an aneurysmal, or blown-out, appearance. It is surrounded by a thin margin of…

Diagnostic Studies. An intense bony reaction to a small nidus is the radiographic hallmark of osteoid osteoma. Radiographs reveal an oval radiolucent nidus only 3 to 5 mm in diameter…

Central Nervous System Manifestations. CNS involvement is thought to affect 10% to 50% of patients, with a mortality rate of up to 20%. In general, CNS involvement is one of…

DIAGNOSTIC CRITERIA Many different criteria are used for diagnosis of Behçet syndrome, but the International Study Group criteria are the most used. Recurrent oral ulcers are required along with two…