When Kidney and Calcium Speak: A Rare Presentation of Sarcoidosis: A Case Report

Though classic pulmonary and constitutional symptoms are present in many cases of sarcoidosis, sarcoidosis can still be clinically silent and limited to the kidneys. This case report presents a 45-year-old Saudi male who presented with non-specific symptoms in the form of fatigue only and significant laboratory findings of PTH-independent hypercalcemia as well as acute kidney injury. Screening for sarcoidosis by chest imaging demonstrated bilateral hilar lymphadenopathy consistent with early sarcoidosis, necessitating renal biopsy to confirm, which then revealed granulomatous interstitial nephritis most likely caused by renal sarcoidosis. This patient was managed mainly by oral prednisone and bisphosphonate, with partial improvement in his serum creatinine, hypercalcemia, and estimated glomerular filtration rate. This case report encourages clinicians to think beyond common causes for presentation such as hypercalcemia, particularly in the presence of acute kidney injury, to avoid irreversible complications caused by unrecognized sarcoidosis.