Because of controversy in the management of nonfunctional adrenal masses <6 cm with lipid-poor imaging characteristics, the study was conducted to compare the costs of observation versus immediate laparoscopic adrenalectomy.

A total of 370 patients who were evaluated for incidental adrenal masses between January 1999 and December 2007 were identified, and 32 (8.7%) patients had lesions with imaging characteristics that were inconsistent with a benign adenoma (ie, atypical appearing). Sixteen patients underwent immediate surgery and 16 had observation with serial imaging and biochemical studies. The associated total costs were subjected to intention-to-treat analysis.

In the observation cohort, 7 patients converted and underwent adrenalectomy after a mean of 13.1 months. Initially, costs of immediate surgery exceeded those of observation ($12,015.72 vs $11,601.18, P = .10). After projecting costs of annual surveillance, a cost advantage for immediate surgery was demonstrated after 9 years (P = .02).

In patients with <6 cm atypical-appearing adrenal lesions, the costs of surgery and of observation are initially equal. After 9 years, the costs of surveillance exceed that of initial laparoscopic adrenalectomy.