Granulomatous intersticial nephritis secondary to sarcoidosis

Granulomatous interstitial nephritis is a rare condition, in which renal involvement is uncommon. Its etiology is variable, and may be medicinal, infectious or inflammatory origin. This is a 65-year-old male patient with renal lesions of unknown etiology, associated with hypercalcaemia. During the investigation, cardiac insufficiency with diastolic dysfunction and interstitial lung involvement on chest tomography were evidenced. Renal function (glomerular filtration rate) has partially improved with clinical measures. Renal biopsy was performed, which showed moderate interstitial lesion with tuberculoid granulomas without caseous necrosis. The objective of the article was to describe a case of NIG and to alert to the importance of its clinical investigation. In this case, renal biopsy, associated with systemic clinical manifestations, contributed to the diagnosis of sarcoidosis.