Introduction:
Sarcoidosis is a multisystemic granulomatous disease involving most commonly the lungs (90%) followed by lymph nodes, skin, and eyes. Renal involvement is rare <1% (Judson MA et al, ACCESS Research Group). The diagnosis of renal sarcoidosis should be suspected in patients who present with renal failure and have either a known diagnosis or extrarenal features of sarcoidosis. Renal sarcoidosis usually manifests with nephrocalcinosis/nephrolithiasis. The characteristic renal biopsy finding is the presence of non-caseating granulomas with tubulointerstitial nephritis. A workup to exclude other causes of granulomatous inflammation of the renal parenchyma is essential.
Methods:
We describe a 32-year-old male patient who presented with vague symptoms of cough without expectoration, generalized weakness and significant weight loss for 2 months.
Results:
Because of respiratory symptoms, a chest X-ray was performed, which showed bilateral lung opacities. CECT revealed multiple mediastinal conglomerated lymph nodes, cavitation in the right lower lobe and centrilobular nodules with ground-glass opacities. On evaluation, he was found to have mild renal failure, subnephrotic proteinuria, hypercalcemia, and anemia. There were no renal calculi. He had no other systemic symptoms like fever, joint pain, or skin rashes. The possibility of active Koch’s or fungal etiology was ruled out by appropriate microscopy and culture. A myeloma workup, done because of hypercalcemia and altered Albumin:Globulin ratio, was negative. Endobronchial biopsy was performed keeping in mind differential of lymphoma or infective etiology, showed non-caseating granulomas. The renal biopsy, performed due to proteinuria, revealed non-caseating granulomas with tubulointerstitial nephritis. The stain for acid-fast bacilli was negative. A diagnosis of sarcoidosis was considered, and Serum ACE level was estimated, which was found to be increased (>140 nmol/ml/min). The patient was started on systemic steroids, to which he responded well.
Conclusions:
Renal sarcoidosis is rare and often a diagnostic challenge. A timely kidney biopsy can help diagnose it and improve outcome.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.