Walsh & Hoyt: Sarcoidosis: Renal Manifestations

Although granulomas may arise in the kidneys of patients with sarcoidosis, they usually are asymptomatic. Instead, the renal dysfunction that occurs in patients with sarcoidosis is caused by disturbed calcium metabolism leading to chronic hypercalcemia and hypercalciuria that may cause formation of renal calculi. Some patients have hypercalciuria without hypercalcemia, and this also is sufficient to produce renal calculi. The calculi, in turn, may produce secondary hydronephrosis, pyelonephritis, nephrocalcinosis, and, ultimately, renal failure.