Endoscopic Ultrasound (EUS) Guided Fine Needle Aspiration (FNA) Biopsy of Solid Pancreatic Lesions: A Review of 111 Cases and Comparative Study of Diff-Quik/PAP/Thin Prep Staining Techniques

Objective: Endoscopic Ultrasound (EUS) guided Fine Needle Aspiration (FNA) biopsy of the pancreas is a standard practice for diagnosis and staging of pancreatic malignancy. The material obtained by EUS guided FNA forms the basis of therapeutic decisions. Methods: 111 cases of EUS guided FNA biopsy of the pancreas performed during the year January 2008 to December 2009 having solid pancreatic mass/lesion on the USG/CT and suspicious for the malignancy or malignant on clinical and radiological investigations were reviewed in August 2011 at the Department of Pathology and Laboratory Medicine, Hospital of University of Pennsylvania, Philadelphia U.S.A Results: There was an 83.9% correlation between Diff-Quick diagnosis and the final cytological diagnosis. The overall diagnostic accuracy for the malignancy was 89.7%, sensitivity 90.6%, and specificity 100% of the cases where the cytological diagnosis was correlated with histological diagnosis and the other investigations. The positive predictive value for the malignancy was 100%. The false negative diagnosis was encountered in 10.3% cases. 51% of the cases showed intranuclear vacuoles, in the malignant cases on Diff-Quik Stain. Conclusions: EUS FNA of the pancreas is a safe and reliable technique with high diagnostic accuracy, sensitivity, and specificity. The Diff-Quik stain smear is a useful technique for the rapid on-site cytological evaluation for the detection of malignancy of the pancreas. Thin Prep was found superior to the PAP / Diff-Quick stain for the diagnosis of the malignancy. The EUS FNA samples processed by multiple staining techniques help to improve the diagnostic accuracy and sensitivity.