Ryoji Miyahara

Background and Study Aim: Ensdoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been reported as a useful technique for histological diagnosis of submucosal or extrinsic gastrointestinal and pancreatic lesions. The aim of this study was to evaluate the use of EUS-FNA for the diagnosis of lesions either within or adjacent to the wall of the colon and rectum. Patients and Methods: A total of 22 patients with a lesion within the wall of, or adjacent to, the colon or rectum underwent EUS-FNA. They were divided into two groups: patients who had previously had a malignancy (the "previous +ve" group, n =11), and patients who had not previously had a malignancy (the "previous -ve" group, n =11). In the four patients who had lesions located proximal to the sigmoid colon, EUS-FNA was performed using a guide wire and overtube. The success rates for adequate tissue sampling and for detecting malignant and benign masses by EUS-FNA were evaluated and the success rate for detection was compared with the success rate of EUS and computed tomography. Results: Sufficient tissue for evaluation was obtained from 21 of the 22 patients (95.5%). The overall rate of detection of malignant and benign masses was 95.5% (21/22) for EUS-FNA and 81.8% (18/22) for pre-EUS-FNA imaging investigations. Of the 11 patients in the previous +ve group, ten were diagnosed with recurrences of primary malignancies; of the 11 patients in the previous -ve group, four were diagnosed with primary malignancies and seven were diagnosed with benign lesions. There were no complications related to the EUS-FNA procedure. Conclusions: EUS-FNA is a safe technique which is useful in the planning of treatment for patients who have a mass within the wall or adjacent to the wall of the entire length of the colon or rectum.