• Yasir S Elhassan, Fares Alahdab, Alessandro Prete, Danae A Delivanis, Aakanksha Khanna, Larry Prokop, Mohammad H Murad, Michael W O'Reilly, Wiebke Arlt, and Irina Bancos.
• University of Birmingham Institute of Metabolism and Systems Research and Birmingham Health Partners Centre for Endocrinology, Diabetes and Metabolism, Birmingham, United Kingdom (Y.S.E., A.P., M.W.O., W.A.).
• Ann. Intern. Med. 2019 Jul 16; 171 (2): 107-116.

BackgroundAdrenal incidentalomas are mostly benign nonfunctioning adrenal tumors (NFATs) or adenomas causing mild autonomous cortisol excess (MACE), but their natural history is unclear.PurposeTo summarize the follow-up data of adults with NFAT or MACE to determine the proportions of tumor growth, malignant transformation, and incident changes in hormone function; the prevalence of incident cardiometabolic comorbid conditions; and mortality.Data SourcesMEDLINE, Embase, Cochrane, and Scopus (January 1990 to February 2019) and bibliographies of identified articles, without language restriction.Study SelectionStudies that included 20 or more conservatively managed patients with NFAT or MACE and reported outcomes at baseline and after at least 12 months of follow-up.Data ExtractionPairs of reviewers extracted outcomes and assessed methodological quality.Data SynthesisThirty-two studies reported outcomes of 4121 patients with NFAT or MACE, 61.5% of whom were women; the mean age was 60.2 years, and mean follow-up was 50.2 months. Mean tumor growth was 2 mm over 52.8 months. Clinically significant tumor enlargement (≥10 mm) occurred in 2.5% of patients, and none developed adrenal cancer. Clinically overt hormone excess was unlikely to develop (<0.1%) in patients with NFAT or MACE. Only 4.3% of patients with NFAT developed MACE, and preexisting MACE was unlikely to resolve (<0.1%). Hypertension, obesity, dyslipidemia, and type 2 diabetes were highly prevalent (60.0%, 42.0%, 33.7%, and 18.1% of patients, respectively) and were more likely to develop and worsen in MACE than NFAT. New cardiovascular events were more prevalent in MACE (15.5%) than NFAT (6.4%). Mortality was 11.2% and was similar between NFAT and MACE.LimitationEvidence was scarce, and definitions of MACE and comorbid conditions were heterogeneous.ConclusionDuring follow-up, NFAT and MACE do not show clinically relevant changes in size or hormonal function, but they may carry an increased risk for cardiometabolic comorbid conditions.Primary Funding SourceNone.

11 keywords...

hide…