Granulomatous interstitial nephritis in a patient with Crohn's disease.

A case of granulomatous interstitial nephritis (GIN) associated with Crohn's disease (CD) was reported. GIN is a rare pathological finding in renal biopsy specimens. In a patient affected by CD, granulomas may be found in various tissues and organs such as lymph nodes, mesentery, liver, and lungs and occasionally in bones, joints, and skeletal muscle. Few cases of granuloma have been reported in the kidney, and it is not always possible to relate the presence of granuloma to CD, to other interstitial granulomatosis diseases, or to a drug-induced reaction. The issue has a remarkable clinical effect; indeed, the answer requires a completely different therapeutic approach. The diagnosis analysis on the basis of clinical-pathological evidences and on reports from literature is discussed.