Case Presentation:
A 26 year old African-American male with past medical history of pancytopenia and hepatosplenomegaly was transferred to our facility for evaluation of his acute kidney injury. Patient presented with nausea, vomiting, anorexia and weight loss. The hepatosplenomegaly and pancytopenia was found in spring 2011. At that time lymph node, bone marrow and liver biopsies were nondiagnostic. He was found to have a serum creatinine of 4 mg/dL, his creatinine the year before was 1.4 mg/dL. There was no improvement of creatinine with hydration.
Upon presentation to our facility, he was found to be normotensive and physical exam revealed pallor, hepatosplenomegaly but no lymphadenopathy, skin lesions or ocular involvement. His labs showed pancytopenia, elevated alkaline phosphotase and creatinine but normal calcium and angiotensin converting enzyme levels. The urinalysis indicated sterile pyuria, low specific gravity, proteinuria and significant eosinophiluria. The chronic kidney disease workup was negative. Imaging indicated nephromegaly and a normal CT of the chest. Bone marrow and kidney biopsies were obtained. The bone marrow biopsy showed extensive noncaseating granulomatous inflammation. Stains for acid fast bacilli and fungal elements were negative. Kidney biopsy revealed granulamotous interstitial nephritis with focal tubular injury. Patient was started on pulse dose steroids: solumedrol IV daily for three days and then switched to prednisone. He was also started on Bactrim for PCP prophylaxis. He had excellent response to the treatment with improvement in his pancytopenia and creatinine.
Discussion:
Sarcoidosis received its name because the condition causes lesions resembling a sarcoma. It is an idiopathic multisystem granulomatous disorder primarily involving the reticuloendothelial system. It is pathologically characterized by the presence of noncaseating epithelioid granulomas in affected organs. A definitive diagnostic test for sarcoidosis does not exist. Instead, the diagnosis requires three elements – exclusion of other diseases that may present similarly, compatible clinical and radiographic manifestations and histopathologic detection of noncaseating granulomas. Renal involvement, defined by either histologic changes in the kidney or a decline in renal function in the absence of a biopsy, occurs in approximately 15 to 35 percent of patients. The classic renal lesion is noncaseating granulomatous interstitial nephritis, but this rarely causes clinically significant renal disease.
Conclusions:
Renal involvement in sarcoidosis can occur in a variety of ways most common of which include abnormal calcium metabolism, nephrolithiasis and nephrocalcinosis. Glomerular disease, obstructive uropathy, and end-stage renal disease may occur infrequently. It can also present as a rare form of interstitial nephritis with noncaseating granulomas. Typical tubular manifestations include mild proteinuria, sterile pyuria and impaired ability to concentrate urine. Early recognition and initiation of therapy is critical to avoid morbidity and mortality. This particular case presentation had several interesting features viz., absence of overt systemic sarcoidosis, normal serum calcium and angiotensin converting enzyme levels, dramatic response to corticosteroid therapy and most importantly no pulmonary involvement.