Endocrine Abstracts

Introduction: Primary bilateral macronodular adrenocortical hyperplasia (PBMAH) is a rare cause of ACTH-independent Cushing’s syndrome. The optimal treatment approach remains a topic of debate. We present a case of recurrent Cushing’s syndrome following unilateral adrenalectomy for PBMAH.

Case report: A 57-year-old patient, under the care for an independent ACTH hypercorticism related to bilateral macronodular hyperplasia of the adrenal glands, was identified during a routine check-up in the presence of uncontrolled diabetes. A 19-noriodocholesterol scintigraphy was conducted, indicating a slightly higher degree of fixation on the left side (58% on the left vs 42% on the right). The patient underwent unilateral left adrenalectomy, with a favourable clinical and biological course. After seven years of remission, the patient presented with a recurrence of clinical Cushing’s syndrome, an imbalance in his diabetes requiring insulin therapy and in his hypertension requiring three medications. The 24-hour urine free cortisol level was three times the normal range and adrenal CT scan revealed a 6x8x3 cm nodule of the right adrenal gland. The case was discussed and a right adrenalectomy with hormone replacement was recommended.

Discussion: The characteristic feature of PBMAH is the presence of adrenal nodules exceeding 1 cm in diameter. It is a diverse entity, and the underlying pathophysiological mechanisms remain unclear. It is a genetic disorder caused by the inactivation of ARMC5, which is described in 20-25% of PBMAH cases, and KDM1A, which is responsible for >90% of PBMAH cases. The standard treatment is bilateral adrenalectomy, but unilateral adrenalectomy may be an alternative to avoid adrenal insufficiency. In our case, recurrence was noted after seven years of remission, and the decision to perform total adrenalectomy was taken in view of the frank nature of the Cushing’s syndrome and the patient’s cardiovascular risk.