Hypercalcemia Due to Progressive Disseminated Histoplasmosis

Hypercalcemia is a relatively common clinical problem, and evaluation for its etiology may often prove to be challenging. However, a thorough etiological workup can guide effective therapy and can often prove to be lifesaving. We describe a 61-year-old man who presented with fever, anorexia, and weight loss for 3 months, and altered sensorium for around 1 week. His evaluation revealed severe hypercalcemia, correction of which led to improvement in his symptoms. Workup for the cause revealed that he had parathyroid hormone-independent hypercalcemia with elevated levels of 1,25-dihydroxyvitamin D, suggesting a granulomatous disease. Radiological evaluation was suggestive of a multisystem disorder with bilateral adrenal enlargement, generalized lymphadenopathy, and hepatosplenomegaly. Biopsy from the adrenal gland and bone marrow clinched the diagnosis of progressive disseminated histoplasmosis, which required treatment with liposomal amphotericin B for a total duration of 4 weeks, followed by oral itraconazole. The effective treatment was associated with normalization of serum calcium and disappearance of symptoms. Histoplasmosis represents a rare cause of hypercalcemia, with only around 22 such cases having been reported worldwide.