<prompt> Which of the following represents an example of metastatic calcification?Old foci of tuberculosis in the lymph nodesMitral valve damaged by rheumatic feverPulmonary calcification in chronic renal failureBreast cancer visible by mammography  <response>: End-stage renal failure leads to hyperparathyroidism and secondarily to hypercalcemia. The latter results in metastatic calcification. Old foci of tuberculosis, a calcified mitral valve damaged previously by rheumatic fever, and calcification within breast cancer are all examples of dystrophic calcification. 