High prevalence of subclinical hypercortisolism in patients with bilateral adrenal incidentalomas: a challenge to management

P>Objective The prevalence of subclinical hypercortisolism (SH) in unilateral incidentalomas (UI) has been extensively studied; however, patients with bilateral incidentalomas (BI) have not been thoroughly investigated. We therefore aimed to describe the characteristics of patients with BI compared to their unilateral counterparts. The surgical outcome in a small number of patients is reported. Design Observational retrospective study in a single secondary/tertiary centre. Patients One hundred and seventy-two patients with adrenal incidentalomas (41 with BI). Measurements Morning cortisol (F), ACTH, dehydroepiandrosterone sulphate (DHEA-S), midnight F, 24-h urine collection for cortisol (UFC), low-dose dexamethasone suppression test (LDDST), fasting glucose, insulin, and oral glucose tolerance test (OGTT). Primarily, SH was defined as F-post-LDDST > 70 nmol/l and one more abnormality; several diverse cut-offs were also examined. Results No difference was noted in age, body mass index, or prevalence of diabetes and impaired glucose tolerance between patients with UI and those with BI. Patients with BI had higher F-post-LDDST (119 center dot 3 +/- 112 center dot 8 vs 54 center dot 3 +/- 71 center dot 5 nmol/l, P < 0 center dot 001) and lower DHEA-S (1 center dot 6 +/- 1 center dot 5 vs 2 center dot 5 +/- 2 center dot 3 mu mol/l, P = 0 center dot 003) but similar UFC, ACTH and midnight F levels, compared to UI. SH was significantly more prevalent in BI (41 center dot 5% vs 12 center dot 2%, P < 0 center dot 001). Fourteen patients were operated on; four underwent bilateral interventions. In 10 patients, unilateral adrenalectomy on the side of the largest lesion resulted in significant improvement in F-post-LDDST (P = 0 center dot 008) and a decrease in midnight F (P = 0 center dot 015) levels. Conclusions Subclinical hypercortisolism is significantly more prevalent in bilateral incidentaloma patients, posing great dilemmas for its optimum management.