Obstructive uropathy caused by retroperitoneal fibrosis presents as a late manifestation of sarcoidosis

[Kidney involvement in sarcoidosis]

Sarcoidosis is a chronic multisystemic inflammatory disorder of unknown etiology, characterized by the presence of non-necrotizing epithelioid and giant cell granulomas. Various renal manifestations have been reported in patients with sarcoidosis. Disorders of bone and mineral metabolism related to the overexpression of 25-hydroxyvitamin-D1α-hydroxylase by alveolar and granuloma macrophages are frequently associated with sarcoidosis. Hypercalcemia and hypercalciuria are a major cause of renal injury predisposing to pre renal azotemia, acute tubular necrosis, nephrolithiasis and nephrocalcinosis. Therapeutic management of hypercalcemia includes preventive measures (limited sunlight exposure, limited vitamin D and calcium intakes, and adequate hydration) and specific treatment in cases of severe hypercalcemia (corticosteroid therapy, chloroquine or ketoconazole). Granulomatous tubulointerstitial nephritis is the most common renal lesion associated with sarcoidosis leading to end stage renal disease in some patients. In these cases, interstitial fibrosis seems to appear early in the course of sarcoidosis and is a major prognostic factor requiring rapid corticosteroid therapy to reduce the risk of severe renal impairment. Membranous nephropathy seems to be the most frequent glomerular disease that may occur in association with sarcoidosis. Among kidney allograft recipients, the risk of recurrence of granulomatous tubulointerstitial nephritis is high and may have a negative impact on the graft survival.

Urological manifestations of sarcoidosis

PURPOSE

We describe the urological manifestations of sarcoidosis and how the disease may affect the management of multiple urological conditions.

MATERIALS AND METHODS

We performed a PubMed® search using the query sarcoidosis and multiple urological terms.

RESULTS

Sarcoidosis is a disease that has variable manifestations. There is often genitourinary involvement that is clinically silent. However, sarcoidosis may cause symptoms, such as nephrolithiasis, which are sometimes the first manifestation of the disease. Renal function may be affected, and appropriate recognition and treatment may avert progressive functional decline. The presence of sarcoidosis may also confound the diagnosis and staging of various urological malignancies, particularly renal and testicular carcinoma.

CONCLUSIONS

Urologists should be aware of the urological manifestations of sarcoidosis to avoid misdiagnoses and the over staging of urological cancers, and to identify when it is an underlying cause of nephrolithiasis or obstructive uropathy.