SAT-LB066 Clinical Characteristics of Incidentally Discovered Functioning Adrenal Tumors: Study of Advancing Care and Pathogenesis of Intractable Adrenal Diseases in Japan (ACPA-J)

Abstract

Abstract Objectives: Pheochromocytoma and paraganglioma (PPGL), Cushing syndrome (CS), bilateral macronodular adrenal hyperplasia (BMAH) and adrenocortical carcinoma (ACC) are rare adrenal tumors. Hence, collaboration of researchers and clinicians from several institutes and constructing patient registry are important to achieve progress in clinical management. We organized a research group and constructed a patient registry system for adrenal tumors named Advancing Care and Pathogenesis of Intractable Adrenal Diseases in Japan (ACPA-J). In the present study, we focused on incidentally discovered adrenal tumors despite the functioning tumors in ACPA-J database, and investigated their clinical characteristics. Subjects and methods: Clinical data of 176 patients with PPGL, 110 patients with CS, 38 patients with BMAH and 45 patients with ACC who were diagnosed 2006-2016 were registered to ACPA-J database by August 2018. Among the patients who have hormone excess confirmed by endocrinological evaluation, we analyzed the clinical characteristics of an incidentaloma (I) group and a non-incidentaloma (non-I) group in which their tumors were found based on signs and symptoms of adrenal disease, and compared those between two groups. Results: The hormone excess was confirmed in 162 patients with PPGL, 110 patients with CS, 38 patients with BMAH and 36 patients with ACC. Of those, 53.2% of PPGL, 36.7% of CS, 76.5% of BMAH and 24.5% of ACC were incidentaloma, respectively. Age in I group was higher in PPGL, CS and ACC compare to that in non-I group. Tumor size was larger in I group than that in non-I group only in ACC. Incidences of metabolic complications (hypertension, glucose intolerance and hyperlipidemia) were not different between two groups in all type of tumor. In PPGL, urine metanephrine levels and normetanephrine levels were not different between two groups. In CS and BMAH, morning plasma (p-) ACTH levels and p-cortisol levels in the morning, the midnight and after dexamethasone suppression test were not different between two groups. A rate of patients with subclinical cortisol excess was 13% in I group and 14% in non-I group in BMAH, whereas that in I group (50%) was higher than that in non-I group (23%) in ACC. Conclusions: The adrenal incidentaloma is defined as the tumor unexpectedly found during work-up for an indication unrelated to suspected adrenal disease. Most of the functioning adrenal tumors accompany signs and symptoms of hormone excess and have to be discovered in the process of work-up for adrenal disease. Our result showed there was not particular difference in characteristics between the incidentalomas and the non-incidentalomas. It was suggested that adrenal functioning tumors could be frequently overlooked. (This research was supported by AMED; JP18ek0109352, the Grant for NCGM; 30-A-1008, Health Labour Sciences Research Grant 2018.) Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.