FUNGAL SHADOWS

DIAGNOSTIC AND MANAGEMENT CHALLENGES OF ADRENAL HISTOPLASMOSIS IN AN IMMUNOCOMPETENT ADULT

Abstract

INTRODUCTION/BACKGROUND
Histoplasmosis is a fungal infection caused by Histoplasma capsulatum. Disseminated histoplasmosis involving bilateral adrenal glands and resulting in adrenal insufficiency is rare, particularly in immunocompetent individuals. The non-specific symptoms often mimic other diseases, making timely diagnosis difficult, especially in resource-limited settings. We report a case of disseminated histoplasmosis with adrenal insufficiency in an immunocompetent individual presenting with bilateral adrenal masses.

CASE
A 69-year-old previously healthy male presented with generalized body weakness, intermittent fever and significant weight loss of 20 kg over three months. There were no other remarkable symptoms. Initial PET-CT scan revealed large bilateral adrenal masses with hypermetabolic rims and central metabolism (right: 8.3 x 6.6 x 8.8 cm; left: 8.6 x 6.6 x 9.7 cm) as well as hepatosplenomegaly and right lung changes suggestive of infection or malignancy. The investigations for tuberculosis and HIV were negative. Tissue biopsies of the masses revealed acute granulomatous lesions indicative of fungal infection. The patient was started on intravenous Amphotericin B, followed by maintenance therapy with oral itraconazole. An ACTH stimulation test showed inadequate adrenal response, and steroid replacement therapy was initiated. Despite nine months of antifungal therapy, he showed minimal clinical improvement. Repeat imaging demonstrated increased adrenal mass size, prompting bilateral adrenal drainage following a multidisciplinary team discussion. Histopathology confirmed ongoing fungal infection, and fungal sequencing identified Histoplasma capsulatum.

A second course of IV liposomal Amphotericin B was administered, followed by itraconazole. The patient’s fever resolved, and follow-up imaging showed reduction in adrenal mass size. He remains on drainage and long-term antifungal therapy, planned for at least 18 months.

CONCLUSION
This case highlights the diagnostic challenges of adrenal histoplasmosis in immunocompetent individuals presenting with vague systemic symptoms and large bilateral adrenal masses. Early recognition and a multidisciplinary approach are crucial for timely diagnosis and optimal management.