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 (119·3 ± 112·8 vs 54·3 ± 71·5 nmol/l, P<0·001) and lower DHEA-S (1·6 ± 1·5 vs 2·5 ± 2·3 μmol/l, P=0·003) but similar UFC, ACTH and midnight F levels, compared to UI. SH was significantly more prevalent in BI (41·5%vs 12·2%, P<0·001). 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=0·008) and a decrease in midnight F (P=0·015) levels.
Conclusions: Subclinical hypercortisolism is significantly more prevalent in bilateral incidentaloma patients, posing great dilemmas for its optimum management.
© 2011 Blackwell Publishing Ltd.