Adrenal Insufficiency With Normal Serum Cortisol Due to Large, Bilateral Adrenal Metastases

ABSTRACT Objective Herein, we report a case of adrenal insufficiency due to bilateral adrenal metastases in which random serum cortisol was in the normal range. Methods Case details and literature review. Results A 68-year-old woman under treatment for ovarian cancer was referred for endocrine consultation because of bilateral adrenal metastases, weakness, and orthostatic symptoms. Biochemical evaluation found that despite normal levels of serum cortisol, she had primary adrenal insufficiency. A review of the literature found that normal levels of serum cortisol are typical in rare cases of adrenal insufficiency due to adrenal metastases. Conclusion In cancer patients with bilateral adrenal metastases, cortisol production is enhanced and unregulated. In those rare cases when adrenal insufficiency is caused by bilateral adrenal metastases, serum cortisol may be normal, and accurate diagnosis requires further biochemical evaluation, including measurement of plasma adrenocorticotropic hormone (ACTH) and serum cortisol after infusion of synthetic ACTH.