Endoscopic ultrasound-guided fine needle aspiration and/or biopsy (EUS-FNA/B) have been used to diagnose subepithelial tumors (SETs) and extraluminal lesions in the gastrointestinal tract. Our group previously reported the usefulness of EUS-FNA/B for rectal and perirectal lesions. This study reports our expanded experience with EUS-FNA/B for rectal and perirectal lesions in terms of diagnostic accuracy and safety. We also included our new experience with EUS-FNB using the recently introduced ProCore needle.

From April 2009 to March 2014, EUS-FNA/B for rectal and perirectal lesions was performed in 30 consecutive patients. We evaluated EUS-FNA/B performance by comparing histological diagnoses with final results. We also investigated factors affecting diagnostic accuracy.

Among 10 patients with SETs, EUS-FNA/B specimen results revealed a gastrointestinal stromal tumor in 4 patients and malignant lymphoma in 1 patient. The diagnostic accuracy of EUS-FNA/B was 50% for SETs (5/10). Among 20 patients with non-SET lesions, 8 patients were diagnosed with malignant disease and 7 were diagnosed with benign disease based on both EUS-FNA/B and the final results. The diagnostic accuracy of EUS-FNA/B for non-SET lesions was 75% (15/20). The size of lesions was the only factor related to diagnostic accuracy ( P =0.027). Two complications of mild fever and asymptomatic pneumoperitoneum occurred after EUS-FNA/B.

The overall diagnostic accuracy of EUS-FNA/B for rectal and perirectal lesions was 67% (20/30). EUS-FNA/B is a clinically useful method for cytological and histological diagnoses of rectal and perirectal lesions.