Asia Oceania Journal of Nuclear Medicine and Biology

Asia Oceania Journal of Nuclear Medicine and Biology

Bilateral adrenal histoplasmosis incidentally detected on 18F-FDG PET/CT in an immunocompetent man with primary adrenal insufficiency: A case report

Document Type : Case report

Authors
Dr Nitin Gupta 1
Amit Rana 2
1 Department of Nuclear Medicine, Dr Rajendra Prasad Government Medical College (RPGMC), Tanda, Kangra, Himachal Pradesh, India
2 Department of Oncology, Dr Rajendra Prasad Government Medical College (RPGMC), Tanda, Kangra, Himachal Pradesh, India
10.22038/aojnmb.2026.92421.1683
Abstract
Adrenal histoplasmosis is an uncommon manifestation of Histoplasma capsulatum infection and may closely mimic malignancy or granulomatous diseases on imaging. We describe an immunocompetent 51 year old man with 5 months of constitutional symptoms who underwent 18F-FDG PET/CT for evaluation of occult disease. The scan revealed intensely FDG avid bilateral adrenal masses with necrotic components, with no other abnormal sites. Biochemical testing confirmed primary adrenal insufficiency. CT guided adrenal biopsy, targeted to the most FDG-avid viable component, demonstrated necrotizing granulomatous inflammation with intracellular yeast forms consistent with Histoplasma capsulatum. Antifungal therapy with itraconazole plus glucocorticoid replacement led to clinical improvement and interval regression of adrenal lesions on follow-up. This case highlights the value of 18F-FDG PET/CT for detecting unsuspected adrenal histoplasmosis, localizing optimal biopsy targets, and facilitating timely treatment even in immunocompetent patients presenting with nonspecific symptoms.
Keywords
Adrenal histoplasmosis
18F-FDG PET/CT
Adrenal insufficiency
Fungal infection
Subjects
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Asia Oceania Journal of Nuclear Medicine and Biology
Volume 14, Issue 2
July 2026
Pages 209-212