A CT scan of a 43-year-old woman with a parathyroid adenoma and hyperparathyroidism reveals extensive calcium deposits in the lungs and kidney parenchyma. These radiologic findings are best explained by which of the following mechanisms of disease?

Metastatic calcification. Metastatic calcification is associated with an increased serum calcium concentration (hypercalcemia). Almost any disorder that increases serum calcium levels can lead to calcification in the alveolar septa of the lung, renal tubules, and blood vessels. The patient in this case had a parathyroid adenoma that produced large quantities of parathyroid hormone. Other examples of metastatic calcification include multiple opacities in the cornea of a child given large amounts of vitamin D and partially calcified alveolar septa in the lungs of a patient with breast cancer metastatic to bone. Breast cancer metastases to bone are often osteolytic and, therefore, accompanied by hypercalcemia. Dystrophic calcification (choice B) has its origin in direct cell injury. Arteriosclerosis (choice A) is an example of dystrophic calcification.Diagnosis: Hyperparathyroidism, metastatic calcification