Study of abnormal adrenal receptors in subjects with ACTH-independent Cushing's syndrome and nodular adrenal hyperplasia

Introduction: ACTH-independent Cushing's Syndrome (AICS) accounts for 15-20% of cases of Cushing's syndrome, with <1% due to abnormal receptors. Our aim is to study the presence of abnormal receptors in subjects diagnosed with AICS with nodular adrenal hyperplasia in a 14-year period (2002-2016), as well as its clinical-biological and evolutive characteristics.

Material and methods: A multicentre descriptive study of a 15-case series of AICS with nodular adrenal hyperplasia (study period: 2002-2016). In these cases, abnormal receptor screening was performed by means of stimulation tests, with a plasma cortisol increase of ≥ 25% from baseline being considered pathologic.

Results: Of the 15 cases, 13 were female, with a mean age at diagnosis of 56.8 years. In 12 of the 15 cases studied, positivity was detected with stimulation tests, and, of them, 25% were positive for the meal test, 58.3% for posture walking test, 33.3% for desmopressin; 25% for terlipressin; 33.3% for GnRH; 25% for LH and 50% for metoclopramide. Regarding treatment, bilateral adrenalectomy was performed in 16.7% and unilateral adrenalectomy in 41.7%. The rest continue under observation with periodic follow-up (41.7%).

Conclusions: In most of the cases studied with AICS and nodular adrenal hyperplasia (80%), an abnormal cortisol response is detected due to the presence of abnormal receptors. The test with the highest percentage of positivity was the postural walking test (58.3%).