The Etiology Of Benign Adrenal Incidentalomas And Its Relationship With Thyroid Function

Objective:To summarize the different characteristics of benign adrenal incidentalomas,and to explore the relationship between benign adrenal incidentalomas and thyroid function.Methods:We collected clinical data of 80 patients with benign adrenal incidentalomas,who admitted to the First Affiliated Hospital,College of Medicine,Zhejiang University from June 2018 to June 2019.The data include baseline data characteristics,endocrine function test results,clinical diagnosis,postoperative pathological diagnosis.The relevant data were analyzed by SPSS 23.0,and relationship between the function of adrenal incidentalomas of different etiology and thyroid function was further analyzed.Results:Of the 80 patients with benign incidentalomas,34 were male?42.5%?and 46 were female?57.5%?.The average age of consultation was?53.24±11.27?years old.The patients were divided into 5 groups according to different etiology,including non-functional adrenal incidentalomas?NFAI?,pheochromocytoma and paraganglioma?PPGL?,primary aldosteronism?PA?,possible autonomous cortisol secretion?PACS?and autonomous cortisol secretion?ACS?.Of these,58 were nonfunctional adenomas?72.5%?,22 were functional adrenal incidentalomas?27.5%?,6 were PPGL?7.5%?,and4 were PA?5%?.A total of 12?15%?tumors secreted cortisol.Among them,4 cases?5%?were PACS and 8 cases?10%?were ACS.The 4pm cortisol level?F₄?and the 12am cortisol level(F₁₂)were significantly higher in the ACS group than in the NFAI group?P<0.05?.The 8am adrenocorticotrophic hormone level?ACTH₈?was significantly lower in the ACS group than in the NFAI group?P<0.05?.Plasma renin activity?PRA?in PA group were significantly lower than those in PPGL group and NFAI group?P<0.05?.The aldosterne-to-renin ratio?ARR?of PA group was significantly higher than that of PPGL group and NFAI group?P<0.05?.The metanephrine level in PPGL group was significantly higher than that in ACS group?P<0.05?.FT₃in ACS group was significantly lower than that in NFAI group,PA group and PACS group?P<0.05?.There was a negative correlation between FT₃and F₁₂in patients with benign adrenal incidentalomas,which may be related to the continuous trace secretion of cortisol by benign adrenal incidentalomas.Conclusion:Most benign adrenal incidentalomas are non-functional adenomas.Functional adrenal incidentalomas are mainly PPGL,PA,ACS,and PACS.FT₃levels are lower in ACS group,and patients with benign adrenal incidentalomas have a negative correlation with FT₃and F₁₂levels.Clinicians should note that patients with benign adrenal incidentalomas with lower FT₃levels may be due to primary adrenal disease.