Hypercalcemia Due to Progressive Disseminated Histoplasmosis

Area of Science:

• Internal Medicine
• Infectious Diseases
• Endocrinology

Background:

• Hypercalcemia presents a common yet diagnostically challenging clinical issue.
• Identifying the underlying etiology of hypercalcemia is crucial for effective and potentially life-saving treatment.

Observation:

• A 61-year-old male presented with constitutional symptoms and altered sensorium, revealing severe hypercalcemia.
• Laboratory results indicated parathyroid hormone-independent hypercalcemia with elevated 1,25-dihydroxyvitamin D levels, suggesting a granulomatous etiology.
• Radiological findings showed a multisystem disorder including adrenal enlargement, lymphadenopathy, and hepatosplenomegaly.

Findings:

• Diagnosis of progressive disseminated histoplasmosis was confirmed via adrenal gland and bone marrow biopsy.
• Treatment involved liposomal amphotericin B followed by itraconazole, leading to serum calcium normalization and symptom resolution.
• This case highlights histoplasmosis as an infrequent cause of hypercalcemia, with fewer than 22 reported instances globally.

Implications:

• This case underscores the importance of considering rare infectious etiologies in the workup of hypercalcemia.
• Effective antifungal therapy can successfully resolve hypercalcemia and associated symptoms in histoplasmosis.
• Raising awareness of histoplasmosis as a cause of hypercalcemia can improve diagnostic timeliness and patient outcomes.