RF33 | PSUN01 Clinical Course of Benign Adrenal Cysts: A Single-Center Experience of 90 Patients

INTRODUCTION: Benign adrenal cysts (BACs) comprise 1% of adrenal incidentalomas. Scarce data are available to guide hormonal evaluation and management. We aimed to describe the clinical presentation, imaging characteristics and outcomes of patients with BACs. METHODS: This was a single center retrospective study of patients with histologically or radiologically confirmed BACs evaluated between 1995-2021. Other cystic adrenal lesions (such as cystic pheochromocytoma and adrenocortical cancer) were excluded. Medical records were reviewed for clinical, biochemical, radiological, and surgical information. Subgroup analyses based on surgical versus nonsurgical management was performed. RESULTS: BACs were diagnosed in 92 patients (53, 57% women) at a median age of 45 years. Mode of discovery was incidental on imaging in 81 (88%), symptoms of mass effect in 9 (9.8%), and other in 2 (2.2%). Majority (89, 97%) of patients had unilateral cysts (45 right, 44 left) with a median size of 48 mm (range 4-200) at diagnosis. On imaging, most cysts were round/oval (85.4%), homogenous (83.2%) lesions with calcifications (64.0%) and no vascular enhancement (97.7%). During a median follow-up of 65 months (range 7-288), adrenal cysts demonstrated minimal enlargement (median size change 6 mm, median growth rate 2 mm/year).Age of diagnosis, sex, site and initial size of BAC were not associated with an increase in size during follow up. On hormonal evaluation, 10% (5/50 tested) had an abnormal overnight dexamethasone suppression test, and 9.5% (4/42 tested) had an abnormal case detection testing for primary aldosteronism. Adrenalectomy was performed in 46 (51%) patients. Patients treated with adrenalectomy (46, 50%) were younger (36.9 vs 50.8 years, P=0.0009) and had more rapidly enlarging cysts (median growth rate 5.5 vs 0.4 mm/year, P=0.0002). CONCLUSIONS: BACs are usually incidentally discovered and nonfunctional lesions with excellent prognosis, irrespective of management. On imaging, benign adrenal cysts appear as large, homogenous lesions without vascular enhancement that demonstrate slow growth. Adrenalectomy should be reserved for the minority of patients with abnormal hormonal evaluation or imaging characteristics (heterogenous, vascular enhancement) concerning for an alternate etiology, or those who develop symptoms of mass effect. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Monday, June 13, 2022 12:42 p.m. - 12:47 p.m.