Frequency of mediastinal lymph node metastases in patients undergoing EUS evaluation of pancreaticobiliary masses

Background. Mediastinal lymph node metastases; have rarely been reported in patients with pancreatic cancer. Our aim was to determine the frequency of mediastinal lymph node metastases in patients with pancreaticobiliary mass es by using EUS-guided fine needle aspiration. Methods: Sixty-six consecutive patients with pancreatobiliary masses were e valuated on EUS for the presence of mediastinal lymph node metastases. All masses were staged by commonly used EUS criteria by using sector scanning e choendoscopes. Mediastinal lymph nodes with EUS features that suggested mal ignancy were aspirated. Results. Of the 66 patients (mean age 65.6 years; 38 men), 4 had biliary ma sses, 5 had lesions of the major duodenal papilla, and 57 had pancreatic ma sses. Eleven patients (10 pancreatic masses, 1 biliary mass) had enlarged m ediastinal lymph node (12-30 mm) on EUS; in 2 patients these had a benign a ppearance and were not aspirated. Nine patients underwent EUS-guided fine n eedle aspiration: in 1 the cytology was inconclusive (patient subsequently had a negative Whipple resection); in 4 the mediastinal lymph node cytology was benign; the remaining 4 patients had adenocarcinoma cells in the aspir ate from mediastinal lymph node. These 4 pancreatic tumors were staged by E US as T2N1M1 (1), as T4N0M1 (2, one later found to also have a lung mass), and T4N1M1 (1). Conclusion: Enlarged mediastinal lymph nodes were found on EUS in 16.6% (95 % Cl [7.7%, 25.6%]) of patients with pancreatobiliary masses and in 17.5% ( 95% Cl [7.6%, 27.4%]) of patients with pancreatic masses. The frequency of mediastinal lymph node metastases in pancreatobiliary masses was 6.1% (95% CI [0.34%,11.9%]) and in pancreatic masses 7.0% (95% CI [0.4%,13.6%]). Rout ine EUS evaluation of the mediastinum in patients with pancreatic masses is warranted.