Isolated sarcoid renal granulomatous tubulointerstitial disease

A 37-year-old lady presented with hypercalcemia and acute renal impairment. She had no previous medical problems apart from the use of non steroidal anti-inflammatory drugs for nonspecific body pains. Her abdominal ultrasound scan as well as urine studies were nonspecific. Further workup for hypercalcemia (skeletal survey,high resolution computed tomography (CT) of the chest and abdomen,purified protein derivative (PPD) test,serum protein electrophoresis,tumor markers,immunology screening,and Bence Jones proteinuria) was negative. Serum angiotensin converting enzyme was high. Renal biopsy showed extensive lymphocytes and multinucleated giant cells infiltration forming interstitial non necrotizing granulomata. Immune staining as well as staining for acid fast bacilli was negative. The possibility of sarcoid renal granulomata was raised and the patient was started on oral prednisolone with subsequent normalization of renal functions and serum calcium after one month of treatment.