Calcification and bone marrow formation in ureteropelvic junction obstruction

Abnormal deposits of calcium in ischemic and necrotic tissue is a common finding in human pathological conditions. Calcium is found in 1 to 2 per cent of renal cysts and 10 per cent of renal cell carcinomas. Calcification in hydronephrosis secondary to ureteropelvic junction obstruction is rare. No cases of bone marrow arising within a calcified renal mass have been reported.