No Postoperative Adrenal Insufficiency in a Patient with Unilateral Cortisol-Secreting Adenomas Treated with Mifepristone Before Surgery

BACKGROUND Glucocorticoid replacement is commonly required to treat secondary adrenal insufficiency after surgical resection of unilateral cortisol-secreting adrenocortical adenomas. Here, we describe a patient with unilateral cortisol-secreting adenomas in which the preoperative use of mifepristone therapy was associated with recovery of the hypothalamic-pituitary-adrenal (HPA) axis, eliminating the need for postoperative glucocorticoid replacement. CASE PRESENTATION A 66-year-old Caucasian man with type 2 diabetes mellitus, hyperlipidemia, hypertension, and obesity was hospitalized for Fournier's gangrene and methicillin-resistant Staphylococcus aureus sepsis. Abdominal computed tomography scan revealed three left adrenal adenomas measuring 1.4, 2.1, and 1.2 cm and an atrophic right adrenal gland. Twenty-four-hour urinary free cortisol level was elevated (237 µg/24 hours, reference range 0-50 µg/24 hours). Hormonal evaluation after resolution of the infection showed an abnormal 8 mg overnight dexamethasone suppression test (cortisol postdexamethasone 14.5 µg/dL), suppressed adrenocorticotropic hormone (ACTH; <5 pg/mL, reference range 7.2-63.3 pg/mL), and low-normal dehydroepiandrosterone sulfate (50.5 µg/dL, male reference range 30.9-295.6 µg/dL). Because of his poor medical condition and uncontrolled diabetes, his Cushing's syndrome was treated with medical therapy before surgery. Mifepristone therapy was started and, within five months, his diabetes was controlled and insulin discontinued. The previously suppressed ACTH increased to above normal range accompanied by an increase in dehydroepiandrosterone sulfate levels, indicating recovery of the HPA axis and atrophic contralateral adrenal gland. The patient received one precautionary intraoperative dose of hydrocortisone and none thereafter. Two days postoperatively, ACTH (843 pg/mL) and cortisol levels (44.8 µg/dL) were significantly elevated, reflecting an appropriate HPA axis response to the stress of surgery, and two weeks postoperatively, ACTH was within normal range and a repeat dexamethasone suppression test was normal. Six months postoperatively, ACTH was within normal limits and cortisol was approaching normal. The patient has exhibited no postoperative signs or symptoms of adrenal insufficiency in 12 months. CONCLUSION Preoperative mifepristone therapy was associated with apparent recovery of the HPA axis prior to unilateral adrenalectomy in a patient with unilateral adrenal adenomas. Postoperatively, the patient experienced no signs or symptoms of adrenal insufficiency and no glucocorticoid replacement was required.