Mitral annular calcification and liquefaction necrosis of this lesion mimicking intracardiac tumor because of secondary hyperparathyroidism have been described in adult patients with chronic renal failure, but have not been reported in children. Chronic renal failure is one of the predisposing factors of this condition. We report the case of a 13-year-old patient with continuous ambulatory peritoneal dialysis with severe hyperparathyroidism who was found to have intracardiac and rib lesions considered to be brown tumors.