Diagnostic Challenges in a Case of Refractory Severe Hypercalcemia Due to Splenic Sarcoidosis.

Hypercalcemia is frequently encountered in clinical practice; however, sarcoidosis-induced hypercalcemia is relatively uncommon and requires careful evaluation, particularly when initial investigations are inconclusive or the hypercalcemia is refractory to standard treatment. We present a complex case of a 60-year-old female with chronic stage IV diabetic nephropathy who presented with acute severe asymptomatic hypercalcemia resulting from splenic sarcoidosis confirmed on splenic biopsy. Despite commencement of prednisone therapy, her hypercalcemia persisted. IV fluid therapy was complicated by fluid overload from chronic renal disease. Ketoconazole was trialed as second-line therapy with no initial improvement. Our case illustrates the diagnostic and therapeutic challenges associated with asymptomatic hypercalcemia attributed to systemic sarcoidosis on a background of chronic renal impairment. It underscores the importance of considering systemic sarcoidosis as a potential etiology in cases of acute PTH-independent hypercalcemia resistant to initial therapy.