Endoscopic ultrasound-guided fine needle aspiration as a diagnostic and staging tool for rectal and perirectal lesions-an institutional experience

The role of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in evaluating lesions adjacent to the upper gastrointestinal tract wall is well established. However, this tool is underused in evaluating rectal and perirectal lesions, possibly due to insufficient experience and underrecognized value of this procedure. In this study, we report our institutional experience with EUS-FNA as a diagnostic and staging tool for rectal and perirectal lesions. A retrospective chart review was performed and a cohort of 38 patients who underwent rectal EUS-FNA (41 specimens) at our institution between January 2002 and July 2012 was retrieved. The cytology diagnoses were compared with the concurrent or follow-up histologic and clinical diagnoses. Among the total 41 cases, rectal EUS-FNA was performed as a diagnostic procedure in 22 (54%) and a staging procedure in 19 (46%) cases. On cytology examination, 18 cases (44%) were diagnosed as malignant; 1 (2%), as atypical/suspicious for malignancy; 3 (7%), as benign neoplastic; 13 (32%), as nonneoplastic; and 6 (15%), as nondiagnostic cases. Concurrent or follow-up histologic diagnoses were available in 20 cases (48%), 19 of them had concordant cytological/histologic findings (10 benign, 9 malignant). One perirectal lymph node with negative cytology diagnosis was found to be positive on histologic examination, probably due to sampling error on cytology. The sensitivity and specificity of EUS-FNA for detecting malignant rectal/perirectal lesions in this study were 91% and 100%, respectively. Endoscopic ultrasound-guided fine needle aspiration is a useful diagnostic tool for rectal/perirectal lesions; it confirms or excludes malignancy for lesions with high or low clinical suspicions. It serves as a reliable staging method to identify patients for proper clinical management.