Delayed Bilateral Adrenal Enlargement in a Patient With Disseminated <i>Mycobacterium Avium Complex</i> Infection

Bilateral adrenal lesions account for 20% of adrenal incidentalomas and have a broad differential diagnosis. We present a case of a 56-year-old woman with HIV on antiretroviral therapy (ART), internal jugular vein thrombus on anticoagulation, and recent diagnosis of disseminated <i>Mycobacterium avium-intracellulare complex</i> (MAC) infection, who presented with enlarging bilateral adrenal nodules 6 months after starting treatment for MAC. Imaging was consistent with lipid-poor adrenal lesions. Given the clinical context, diagnoses considered included mycobacterium and fungal infections, lymphoma, pheochromocytoma, and adrenal hemorrhage. Biochemical testing was negative for pheochromocytoma and other adrenal hormone overproduction. Clinically significant adrenal insufficiency was excluded. Infectious work-up was also unremarkable. Of note, her ART was adjusted when she initiated MAC treatment with significant improvement in CD4 count. Adrenal biopsy was pursued and showed granulomatous inflammation likely secondary to MAC. This case demonstrates that delayed bilateral adrenal enlargement can be seen in patients with HIV and disseminated MAC infection who also have CD4 count improvement during treatment. Although rarely indicated, adrenal biopsy can be crucial in making the right diagnosis and directing clinical management.