Unilateral Adrenalectomy as a First-Line Treatment of Cushing's Syndrome in Patients With Primary Bilateral Macronodular Adrenal Hyperplasia.

Context: Bilateral adrenalectomy is the reference treatment for Cushing's syndrome (CS) related to primary bilateral macronodular adrenal hyperplasia (PBMAH). It is, however, responsible for definitive adrenal insufficiency.
Objective: The objective of the study was to evaluate the clinical interest of unilateral adrenalectomy (UA) of the larger gland for the treatment of CS related to PBMAH.
Design, Setting, Patients, and Intervention: This was a retrospective study in four tertiary French centers including all 15 patients with PBMAH and CS who underwent UA of the larger gland between 2001 and 2015.
Main Outcome Measures: Urinary free cortisol, plasma cortisol, ACTH, body mass index, blood pressure, plasma glucose, and lipids were registered pre- and postoperatively and on follow-up. Median follow-up was 60 months (interquartile range 39-105), including 8 of 15 patients followed up for at least 5 years.
Results: A normal or low urinary free cortisol was obtained in 15 of 15 patients (100%) postoperatively. Six patients (40%) became adrenal insufficient, of whom three of six recovered a quantitatively normal cortisol secretion on follow-up. Decrease of both body mass index and blood pressure were observed at 1 year, and decrease of blood pressure was persistent 5 years postoperatively. Diabetes was cured in four of six patients. Two patients experienced a recurrence of hypercortisolism, and one was treated with mitotane, whereas the other underwent a second adrenal surgery 9 years after initial UA.
Conclusion: UA induced remission of hypercortisolism in all patients, with sustained significant clinical improvement. The rates of both definitive adrenal insufficiency and 5-year recurrence were low. UA appears an interesting alternative to bilateral adrenalectomy as a first-line treatment in PBMAH responsible for overt CS.