Lesions diagnosed as malignant by cytopathology on EUS-FNA sample and finally confirmed by surgery or clinical course will be considered to be true positives (TPs); similarly, benign aspirates finally diagnosed as benign will be considered to be true negatives (TNs). On the other hand, those aspirates apparently benign at cytopathological examination which will be finally diagnosed as malignant will be considered to be false negatives (FNs). Non-diagnostic/inconclusive samples will be registered as such in the database and for analytical purposes when computing diagnostic accuracy will be classified as FNs.