The utility of urovysion fluorescence in situ hybridization in pancreatic fine-needle aspiration samples directed and obtained by endoscopic ultrasonography

Context.-The diagnosis of pancreatic adenocarcinoma can be challenging for the pathologist. Endoscopic ultrasound-guided, fine-needle aspiration (EUS-FNA) can be used to obtain samples of pancreatic masses. UroVysion fluorescence in situ hybridization (UFISH) has been reported to increase the sensitivity and to be very specific for the diagnosis of adenocarcinoma when combined with cytology in the diagnosis of biliary brushings and washings. Objectives.-To determine the sensitivity and specificity of UFISH on tissues obtained from pancreatic lesions suggestive of adenocarcinoma obtained by EUS-FNA, compared against fine-needle aspiration (FNA) results. Additionally, to use patient follow-up data to evaluate UFISH results in FNA samples that showed significant atypia but did not meet the criteria for malignancy. Design.-Sixty consecutive cases of pancreatic EUS-FNA from our institution submitted for UFISH testing. Results.-Polysomic UFISH has a sensitivity of 93% and a specificity of 100% when compared against FNA results. Follow-up studies showed that adding UFISH to FNA increased the sensitivity for patients with true-positive results from 83% to 94% and increased specificity from 85% to 100%. For 7 patients with suspicious FNA results who had sufficient follow-up, UFISH was 100% sensitive and 100% specific. Conclusions.-UFISH can be used to confirm the diagnosis of malignancy in pancreatic adenocarcinoma. Because of the high specificity, polysomic UFISH may help establish a diagnosis of malignancy when the FNA features are suggestive of, but not conclusive for, malignancy. The most common cause for a false-negative UFISH result was insufficient numbers of malignant cells.