PREOPERATIVE BIOPSY OF PARARECTAL LYMPH-NODES IN RECTAL-CANCER USING ENDOLUMINAL ULTRASONOGRAPHY

PURPOSE: Because definitive information regarding lymph node status in rectal cancer would be valuable preoperatively, we evaluated the safety, feasibility, and accuracy of performing endoluminal ultrasound-guided biopsies of pararectal lymph nodes in 26 rectal cancer patients. Biopsies were compared with the pararectal tissues removed at surgery. METHODS: Using a longitudinally oriented 7.0-MHz ultrasound probe and an 18-gauge spring-loaded core biopsy needle, patients underwent biopsies of lymph nodes detected ultrasonographically without complications. RESULTS: A biopsy of adenocarcinoma was obtained in 13 patients, lymphoid material in 5 patients, and irrelevant material in 8 patients. Accuracy rate (true positives divided by number of procedures) was 77 percent, with a sensitivity of 71 percent, a specificity of 89 percent, a positive predictive value of 92 percent, and a negative predictive value of 62 percent. When adenocarcinoma or lymphoid material was obtained, there was only one false positive and one false negative. CONCLUSION: Endoluminal ultrasonography-guided lymph node biopsy is simple and safe, and when adenocarcinoma or lymphoid material is obtained on biopsy, clinical decision making can be based on this information.