Comparison between the clinical characteristics of patients with adrenal incidentalomas and those with hypertension-associated adrenal tumors in a single center in Japan.

In the largest retrospective study of adrenal incidentalomas (AIs) in Japan between 1999 and 2004, adrenal tumors detected during secondary hypertension (HT) screening were included. The characteristics of patients with adrenal tumors detected during HT screening may differ from those of patients with AIs. This study aimed to compare the characteristics of patients with AIs with those of patients with adrenal tumors detected during HT screening. We retrospectively analyzed patients referred to our division for detailed examination of adrenal tumors between April 2009 and April 2017. When the purposes of imaging tests included HT screening, we defined adrenal tumors as HT associated, otherwise as strictly defined AIs. We reviewed data on age, sex, purpose and modality of imaging, location of tumor, tumor diameter, and hormonal evaluation. We identified 104 patients with HT-associated adrenal tumors and 413 with AIs. Patients with HT-associated adrenal tumors were younger (54.2 years vs. 61.7 years, p < 0.001) and had smaller tumor diameters (1.3 cm vs. 1.9 cm, p < 0.001), lower prevalence of nonfunctioning tumors (24.0% vs. 67.6%, p < 0.001), and higher prevalence of primary aldosteronism (58.7% vs. 4.8%, p < 0.001) than those with AIs. There were no differences in terms of tumor location and prevalence of subclinical Cushing's syndrome, Cushing's syndrome, and pheochromocytoma (18.3% vs. 16.0%, 7.7% vs. 8.0%, and 2.9% vs. 4.6%, respectively). In conclusion, patients with HT-associated tumors were younger and had a smaller tumor with higher prevalence of primary aldosteronism than those with AIs.