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Abstract

Case Presentation: A 55-year-old female with type 2 diabetes and hypertension was initially seen for evaluation of a physical exam remarkable for a dorsocervical fat pad, moon facies, abdominal striae, and hirsutism. An elevated morning cortisol level of 24.8 μg/dL (normal: 4.3–22.4 μg/dL) was subsequently found. Further biochemical evaluation revealed a 24-hour urinary free cortisol of 302 μg/24 hours (normal: 3.5–45 μg/24 hours), an inappropriately normal adrenocorticotropic hormone (ACTH) level of 49 pg/mL (normal: 6–58 pg/mL), and a 1-mg overnight dexamethasone suppression test with a cortisol level of 31.9 mcg/dL (normal: <1.8 μg/dL). An abdominal computed tomography (CT) scan (Fig. 1) showed normal adrenal glands with no hyperplasia or nodules, and pituitary magnetic resonance imaging (MRI) showed a partially empty sella without evidence of an adenoma. She was lost to follow-up, so treatment was not initiated for the ACTH-dependent Cushing syndrome. Six years later, she was admitted for septic shock with a morning cortisol level of 3.2 μg/dL and ACTH of 82 pg/mL. Stress dose steroids were started. Pituitary MRI was negative for pituitary adenoma or hemorrhage. Abdominal CT scan (Fig. 2) showed diffusely enlarged adrenal glands, each measuring 6 cm. A follow up brain MRI showed a small focus of hypoenhancement. Notably, her calcium level was 15.8 mg/dL (normal: 8.4–10.2 mg/dL). An adrenal biopsy was performed, and the histology sample stained with lactophenol cotton blue (Fig. 3). What is the diagnosis?