Malignant mediastinal lymphadenopathy detected by staging EUS in patients with pancreaticobiliary cancer

Background: In patients with pancreatic cancer, the presence of malignant mediastinal lymphadenopathy (MML) would preclude definitive resection. A recent study suggested routine evaluation for mediastinal lymph-node metastases in all patients being evaluated for pancreaticobiliary masses. In our practice, we routinely assess for mediastinal lymph-node metastases in all patients undergoing EUS for pancreaticobiliary cancer. Methods: We retrospectively evaluated the presence of MML by EUS-guided FNA (EUS-FNA) in 160 consecutive patients with a definite diagnosis of pancreaticobiliary cancer (pancreatic and periampullary cancers) who underwent EUS-FNA by a single operator from 2000 to 2004. Lymph nodes that were round and hypoechoic with sharp margins were considered suspicious and were sampled by FNA. Results: Of the 160 patients included in this study, 78 had peripancreatic lymph nodes (49%: 95% CI[41%, 58%]), 25 had celiac lymph nodes (16%: 95% CI[10%, 22%]), and 14 patients had mediastinal lymph nodes (9%: 95% CI[4%, 13%]) that were suspicious for malignancy by morphologic criteria. In 8 of 14 patients with suspicious mediastinal lymph nodes, FNA documented MML in 5%: 95% CI[2%, 8%]. Only one of these 8 patients with MML had other sites of documented distant metastases by CT and/or positron emission tomography scans. However, 7 of 8 patients had locally advanced cancers. Conclusions: MML is detected by staging EUS-FNA in 5% of patients with pancreaticobiliary cancer. Because of its important implications, endosonographers should routinely assess for MML in patients who undergo staging EUS for pancreaticobiliary malignancy.