Background: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is considered as an effective technique to obtain cytology specimens for definite diagnosis of the patients who were suspected of having pancreatic cancer and unknown intra-abdominal lymphadenopathy. The value of repeated EUS-FNA in these patients who had inconclusive first EUS-FNA cytology is not well established.
Objective: To determine the yield of repeated EUS-FNA in obtaining a definite diagnosis in patients with clinically suspect for pancreatic cancer and unknown intra-abdominal lymphadenopathy including the reasons for which initial EUS-FNA failed.
Material and Method: The authors retrospectively reviewed the EUS database of Siriraj endoscopy center, from January 2007 to May 2011, to identify all patients who underwent repeated EUS-FNA for high index suspicion of pancreatic cancer and unknown intra-abdominal lymphadenopathy. The inconclusive results of the first EUS-FNA, the factors associated with nondiagnosed versus diagnosed cytology results were compared.
Results: A total of 478 EUS- FNA were performed in our institution. Fifteen patients (6M, 9F), mean age of 57 + 11.8 years (30-72 years) had repeated EUS-FNA done for the evaluation of possible malignant diseases. Eight of these patients presented with pancreatic masses and the other seven patients had unknown intra-abdominal lymphadenopathy. The second EUS-FNA diagnosed and was truly benign in 4 patients. Repeated EUS-FNA facilitated determination of the true status of the disease in 13 of 15 patients which 9 of whom were malignancy. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of repeated EUS-FNA for both inconclusive pancreatic masses and unknown intra-abdominal lymphadenopathy were 90%, 100%, 100%, 80% and 92.8% respectively.
Conclusion: Repeated EUS-FNA for inconclusive initial cytology of patients with suspected pancreatic cancer and unknown intra-abdominal lymphadenopathy provided a very high yield for definite tissue diagnosis and should be recommended.

Keywords: EUS-FNA, Pancreatic mass, Lymphadenopathy, Repeated, Fine needle aspiration, EUS guided, Pancreatic cancer