Calcinoses

Calcinoses, or calcinosis, refers to abnormal deposition of calcium salts in soft tissues, most often in the skin and subcutaneous tissues. The deposits are typically calcium phosphate crystals (hydroxyapatite). Calcinoses are classified by mechanism into dystrophic, metastatic, iatrogenic, and idiopathic forms.

In dystrophic calcinosis, calcium and phosphate levels in the blood are normal, and deposits develop in areas of tissue damage or inflammation. It is commonly associated with connective tissue diseases such as systemic sclerosis, dermatomyositis, and lupus, and may follow trauma or chronic inflammation. Metastatic calcinosis results from elevated blood calcium or phosphate levels, due to conditions such as hyperparathyroidism, chronic kidney disease with secondary hyperparathyroidism, vitamin D excess, or other disorders of mineral metabolism. Iatrogenic calcinosis arises after medical procedures that introduce calcium-containing solutions or involve repeated injections. Idiopathic calcinosis lacks identifiable metabolic disturbance or preceding tissue injury.

Clinically, calcinoses present as firm, nodular subcutaneous deposits that can be painless or painful, and may ulcerate or become infected. Lesions are often radiopaque on plain X-ray imaging; ultrasound, CT, or MRI can help assess extent and guide treatment. Laboratory evaluation typically includes measurements of serum calcium, phosphate, parathyroid hormone, renal function, and assessment for underlying diseases.

Management focuses on treating the underlying condition and local care. Asymptomatic deposits may be observed, while symptomatic or cosmetically bothersome lesions can be surgically removed or debulked. Medical therapies have variable and limited evidence and may include agents such as calcium channel blockers or bisphosphonates, used on a case-by-case basis. Recurrence after treatment can occur, and prognosis depends largely on the associated underlying disease.