RESUMEN
PURPOSE: Congenital adrenal hyperplasia (CAH) has been associated with adrenal tumors (ATs) but the relationship is still unclear. The aim was to investigate if CAH was more common in patients with adrenal tumors and their characteristics. METHODS: Using national registers all patients with an AT diagnosis (cases) and selected matched controls without AT diagnosis were included from 1st January 2005 to 31st December 2019. The patients with a CAH diagnosis were scrutinized in detail. RESULTS: ATs were diagnosed in 26,573 individuals and in none of 144,124 controls. In 20 patients with ATs and 1 control, a CAH diagnosis was present. The odds for having CAH in patients with ATs was 109 (95% CI 15-809; P < 0.0001). Among cases, 5 had a CAH diagnosis before the discovery of ATs and 15 afterwards. Half were females and two had been screened for CAH neonatally. The mean age when the ATs was discovered was 55.6 years. Adrenalectomy was performed in seven patients. Five patients had unilateral adrenalectomy before the CAH diagnosis and did not have any glucocorticoid protection. After the CAH diagnosis, 15 were initiated on glucocorticoids and 6 on mineralocorticoids. The majority diagnosed with CAH before index date had classic CAH. In individual diagnosed after index date, only three had classic CAH. The rest had nonclassical CAH. During the follow-up time of 9 years, six deceased, two of them in an adrenal crisis. CONCLUSIONS: The prevalence of CAH was greater in patients with ATs than in patients without. In all patients with ATs, CAH should be considered.