Renal insufficiency in sarcoidosis is usually associated with hypercalcemia and hypercalciuria.1-4 These abnormalities of calcium metabolism most frequently result from enhanced gastrointestinal absorption of calcium induced by an increased sensitivity to vitamin D,5 but occasionally occur because of hyperparathyroidism secondary to a parathyroid adenoma.6 The elevated levels of serum and urine calcium ultimately produce renal failure by means of nephrocalcinosis or nephrolithiasis or both with their various sequelae. The occurrence of overt clinical renal disease in sarcoidosis without associated hypercalcemia or hypercalciuria is extremely rare despite the relative frequency of granulomatous renal involvement at necropsy2,4,7 or biopsy material.2,8 Cases of symptomatic nonhypercalcemic sarcoid nephropathy4,7,9-15 have been reported, however. Most have shown a histologic picture of pronounced interstitial inflammation and formation of granulomas,4,9-15 but several cases of membranous glomerulonephritis have been associated with sarcoidosis.16-19
This report describes a patient without hypercalcemia or nephrocalcinosis