Adrenal Insufficiency due to Disseminated Cryptococcus in an Immunocompetent Individual

Primary adrenal insufficiency due to infiltrative fungal infections, such as Cryptococcus neoformans, is rare, particularly in immunocompetent patients. We present a case of an immunocompetent 61-year-old man who presented with bilateral adrenal enlargement and adrenal insufficiency, with a 3-month history of generalised fatigue, weight loss and dizziness, as well as initial hyponatraemia and hyperkalaemia. Adrenal computed tomography (CT) revealed bilaterally enlarged adrenals, and fluorodeoxyglucose positron emission tomography (FDG-PET) revealed increased peripheral metabolic surrounded by a photopenic core suggestive of central necrosis. Adrenal biopsies were consistent with Cryptococcus. Serum cryptococcal antigen (CrAg) testing was strongly positive (titres 1:1280) as was cerebrospinal fluid analysis (titre 1:160). The patient was commenced on hydrocortisone and fludrocortisone, with improvement in symptoms. Treatment involved induction therapy with intravenous liposomal amphotericin-B 4 mg/kg daily and 5-flucytosine 25 mg/kg four times daily for 2 weeks, followed by consolidation therapy with fluconazole. This case highlights the importance of considering disseminated cryptococcosis in immunocompetent individuals presenting with adrenal insufficiency. Early diagnosis and appropriate antifungal therapy are crucial.