ENDOSCOPIC ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION IN THE DIAGNOSIS OF ADRENAL METASTASIS IN A HIGH-RISK POPULATION

Objective: While the left adrenal gland is readily accessible via endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), data regarding the utility of EUS-FNA in the diagnosis of adrenal lesions remain limited. We aimed to (1) describe the clinical context, adverse event rate, and diagnostic performance of EUS-FNA, and (2) compare the safety profile and diagnostic accuracy of EUS-FNA with percutaneous adrenal biopsy. Methods: Single-center, retrospective cohort study. Medical records of patients who underwent adrenal EUS-FNA from 2005-2016 were reviewed. Biopsy outcomes were evaluated using a predefined reference standard. Results were compared to patients who underwent percutaneous biopsy (n = 419; 1994-2014) at the same institution. Results: A total of 121 patients underwent EUS-FNA of 122 adrenal lesions (left [n = 121]; right [n = 1]; mean lesion size, 1.8 cm). Cytology was positive for malignancy in 35 (29%), suspicious for malignancy in 1 (1%), atypical in 1 (1%), negative for malignancy in 81 (66%), and nondiagnostic in 4 (3%). No adverse events were reported. EUS-FNA diagnosed metastasis with a sensitivity of 100%, specificity of 97.4%, positive predictive value of 91.7%, and negative predictive value of 100%. When compared to percutaneous biopsy, lesion size (1.8 cm vs. 3.7 cm; P < .001) and biopsy site (99% vs. 62% left adrenal; P < .001) were significantly different. EUS-FNA adverse event rate was lower than percutaneous biopsy (0% vs. 4%; P = .024), but nondiagnostic rates were similar (3.3% vs. 4.8%; P = .48). Conclusion: EUS-FNA is a sensitive technique to sample adrenal lesions in patients at high risk for adrenal metastasis with fewer adverse events compared to percutaneous biopsy.