The costal cartilages in health and disease.

The costal margin, although imaged in many routine radiologic examinations, has been ignored in the radiology literature. Calcification of the costal cartilages follows gender-related patterns and is generally not evident radiographically until after the age of 30 years. Diffuse enlargement of the costochondral junctions may alert the astute observer to the presence of systemic diseases such as acromegaly and rickets. Focal masses have a subtle appearance on plain radiographs and may be better imaged with computed tomography (CT) or magnetic resonance imaging. Chondrosarcoma of the costal margin typically appears as an expansile mass with coarse calcifications and an associated soft-tissue mass. Radiographic and CT features of costochondritis include chondral enlargement or destruction, low-attenuation cartilage at CT, associated soft-tissue swelling, and localized peripheral cartilage calcification. There appears to be an association between heavy premature costal cartilage calcification and certain systemic conditions, such as malignancy, autoimmune disorders, chronic renal failure, and thyroid disease, particularly Graves disease.