THE PRESENCE of calcification in soft tissues and its radiological appearance may aid in the diagnosis and treatment of certain systemic disorders. When the soft-tissue calcification occurs with an elevated serum calcium-phosphorus ion product, it is termed metastatic calcification. In these patients, amorphous calcium phosphate and calcium hydroxyapatite crystals are deposited in multiple locations. The appearance of metastatic calcification is typical but not disease specific. Microscopically, the deposition of calcium salts may be observed in the lung, stomach, and kidney. Vascular calcification is also present, as are large, periarticular soft-tissue masses.
When soft-tissue calcification occurs in altered, necrotic, or dead tissue in patients whose serum calcium and phosphorus levels are normal, it is called dystrophic calcification, which is influenced by multiple physiological factors. These include serum calcium, phosphorus and alkaline phosphatase,pH of the tissue, vitamin D, hormonal balance, blood supply, and injury of soft tissues.1