Extra-skeletal calcifications An overview of soft tissue calcifications and ossifications

Extraskeletal calcifications is a common radiographic finding. The classification of the deposition of calcium and phosphorous salts in the soft tissues includes metastatic calcification, dystrophic calcification and calcinosis. Metastatic calcification develops when the calcium-phosphorous levels are elevated and implicate normal tissues. Conditions associated with metastatic calcifications are hyperparathyroidism, malignancies, hypervitaminosis D and milk-alkali syndrome. Dystrophic calcification is the calcification occurring in degenerated or necrotic tissues without imbalance in the metabolism of calcium and phosphorous. It is associated with multiple clinical conditions such as venous insufficiency, granulomatous infection, cysticercosis, neoplasms (primary bone forming tumors: osteosarcoma, other sarcomas especially synovial sarcoma), tumor necrosis, scleroderma, dermatomyositis and CREST syndrome, as well as with trauma (heterotopic ossification and injection granuloma). Calcinosis, also known as dystrophic calcification, is a distinct type of extra-skeletal calcification and it is usually not associated with calcium and phosphorus abnormalities. Calcinosis reveals most often in subcutaneous tissues, skin, and related connective tissues. It has been described in inflammatory connective-tissue diseases, including SLE, scleroderma and dermatomyositis. Other associated disorders include: calcinosis universalis, calcinosis circumscripta and tumoral calcinosis.