Endoscopic ultrasound-guided fine needle aspiration in the evaluation of extrarectal pelvic masses

Introduction: The role of endoscopic ultrasound (EUS) in staging rectal cancer is well established but its role in the evaluation of peri-rectal processes is less well defined. The development of the linear array echoendoscope (EE) now allows guided fine needle aspiration (FNA) cytology. We performed this study to determine the role of EUS-guided FNA in the evaluation of pelvic masses. Patients/Methods: Between June 1994 and October 1995, 8 patients were referred for EUS evaluation of pelvic masses. A 360° radial scanning EE was first used to identify the abnormality and establish overall orientation. Next, the linear array EE (Pentax FG 32-UA)was used to perform guided FNA. Pulsed and/or color Doppler were used to distinguish vascular structures. A Teflon catheter with a 23 gauge needle was advanced thru the working channel of the EE and the needle guided into the mass using realtime ultrasound imaging. The FNA specimen was reviewed in the endoscopy suite by a cytopathologist. Results: In 5/8 (63%), a definitive diagnosis of malignancy was made. These included; 2 with adenocarcinoma, 1 with ovarian carcinoma, 1 with cervical carcinoma, and 1 with lymphoma. In 2/8 (25%), the EUS image and FNA were consistent with infection ( pelvic abscess: 1, tubo-ovarian abscess: 1), both were treated accordingly with resolution of symptoms. The EUS images and FNA from the sample of the remaining patient suggested an inflammatory reaction felt to be related to prior radiation therapy. Summary: The diagnostic yield of EUS + FNA was 100% as determined by positive FNA and/or clinical follow-up. The procedures were completed in 45 minutes on average, required no sedation, and there were no biopsy related complications. The total cost excluding cytopathology ranged from $1046-1252 for EUS compared to $1323-1823 for a CT-guided aspiration. 2/5 patients with pelvic malignancies had undergone CT guided FNA with negative results. Conclusions: EUS is able to detect pelvic abnormalities; fine needle aspiration is a useful adjunct for suspected neoplasms and EUS-guided FNA may be a cost-saving diagnostic method in these pts.