Background: In patients with obstructive jaundice and biliary stricture, the role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is debated for fear of missing a potentially resectable pancreatobiliary malignancy (PBM). We evaluated the prevalence of (1) PBM; (2) lesions that do not require a potentially curative cancer surgery; and (3) potentially resectable PBMs in patients with false-negative diagnosis by EUS-FNA.
Patients and methods: This is a retrospective analysis of 342 patients who underwent EUS/EUS-FNA from 2002 to 2009 after presenting with obstructive jaundice and a biliary stricture. Of these, 170 patients had no definitive mass on computed tomography and 172 patients had definitive mass on computed tomography without evidence of unresectability. Final diagnosis was based on surgical pathology or definitive cytology and clinical follow-up of ≥ 12 months.
Results: The mean age of patients (176 male) was 68.0±12.5 years. A final diagnosis of malignancy was made in only 248 patients (72.5%; 95% confidence interval, 67.7, 77.2). The overall accuracy of EUS-FNA for diagnosing malignancy was 92.4% (89.0, 94.8), with 91.5% sensitivity (87.1, 94.5) and 80.9% negative predictive value (72.0, 87.5). Among 21 patients with false-negative diagnosis, 8 had cholangiocarcinoma (2 resectable), 13 had pancreatic cancer (5 resectable). EUS-FNA provided information to potentially modify surgical management in 116 patients (33.9%; 95% confidence interval, 29.1, 39.0): 89 patients diagnosed as true negatives, 24 with distant malignant lymphadenopathy, and 3 with malignant lymphoma.
Conclusions: In above-defined patient subset, the risk of missing resectable tumors by EUS-FNA has been exaggerated because of artifactually low negative predictive value resulting from a high pretest probability of PBM. The actual miss rate for resectable PBM by EUS-FNA is rather small and was 2% in present cohort. Information from EUS-FNA can potentially modify surgical management in up to one third of patients.