True diagnostic ability of EUS-guided fine-needle aspiration/biopsy sampling for small pancreatic lesions ≤10 mm and salvage diagnosis by pancreatic juice cytology: a multicenter study

Abstract

Background and AimsThe diagnostic performance of endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNAB) for pancreatic ductal adenocarcinoma (PDAC) ≤ 10 mm in diameter is relatively low. Pancreatic juice cytology (PJC) has gained attention owing to its high sensitivity for small PDAC. We aimed to clarify the diagnostic ability of EUS-FNAB and the salvage ability of PJC for PDAC ≤ 10 mm. MethodsThe data obtained from attempted EUS-FNAB for patients with EUS-confirmed pancreatic tumors ≤ 10 mm (excluding pancreatic metastases/malignant lymphomas) were retrospectively analyzed. Patients who experienced technical failure/negative EUS-FNAB result and had a strong likelihood of PDAC based on imaging characteristics underwent PJC. PDAC was diagnosed using resected histological specimens, EUS-FNAB-positive tumor growth on the imaging examination, or additional EUS-FNAB-positive results after increase in tumor size. The primary endpoint was the diagnostic ability of EUS-FNAB for PDAC ≤ 10 mm. The salvage ability of PJC was also assessed. ResultsOverall, 86 patients were diagnosed with PDAC of 271 patients with pancreatic tumors ≤ 10 mm who underwent attempted EUS-FNAB. The technical success rate, sensitivity, specificity, and accuracy of EUS-FNAB for PDAC ≤ 10 mm was 80.8%, 82.3%, 94.9%, and 91.3%, respectively. Among the 35 PDAC patients who experienced technical failure/false-negative result of EUS-FNAB, 26 (74.3%) were correctly diagnosed using salvage PJC. ConclusionsThe true success rate/sensitivity of EUS-FNAB for PDAC ≤ 10 mm was relatively low. When EUS-FNAB for a pancreatic lesion ≤ 10 mm strongly suspected to be PDAC is unsuccessful or yields a negative result, PJC is recommended.