Preoperative evaluation of lymph node metastasis in esophageal cancer.

Lymph node metastasis (LMN) in esophageal cancer occurs from the superficial cancer and spreads wildly from the neck to the abdomen. Hence precise determination of LMN is essential when adequate treatments are employed. There are several reports about ultrasonic features of malignant lymph nodes (LNs), and in summary, reports of endoscopic ultrasonography (EUS) findings of malignant LNs showed they were more than 5-10 mm in diameter, with a distinct border, hypoechoic internal echo and round shape. Sensitivity, specificity and accuracies for the diagnosis of malignant LNs by EUS were 49-99%, 33-99% and 71-96%. The rates widely varied, because the accuracy of EUS's ability to determine malignancy were based on the evaluation of various echo features of LNs, and were dependent on the judgement of subjective observers. Therefore histological analysis is necessary for adequate treatments. Endoscopic ultrasonography guided fine-needle aspiration cytology (EUS-FNA) has been performed for the diagnosis of malignant LNs since 10 years. Results of those reports were sensitivity 81-97%, specificity 83-100% and accuracy 83-97%. EUS-FNA staging was better than EUS staging. Also clinically obvious complications by EUS-FNA have not been reported. Therefore published evidence showed that EUS-FNA is safe and useful for confirmation of malignant LNs.