Pancreatic neuroendocrine tumours: a comparison of cytological classification systems.

The results demonstrated that the WHO classification appeared to provide reduced ambiguity when compared with both 'C' and Papanicolaou classification systems; with a lower proportion of cases being classified as suspicious of malignancy as opposed to malignant. The Papanicolaou system was able to supersede the other two systems through its ability to distinguish neuroendocrine tumours from more aggressive entities such as pancreatic adenocarcinoma, thus, offering flexibility in management while still retaining a similar level of accuracy to the WHO classification system in distinguishing benign from malignant lesions.