Onsite evaluation of endoscopic ultrasound fine needle aspiration: the endosonographer, the cytotechnologist and the cytopathologist.

Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) has become an essential tool in the management of multiple diseases. Its accuracy is related to different aspects of the technique, one of the most important being the experience and interaction of the endosonographer and pathologist. Certain studies over the past years have highlighted the importance of having rapid on-site evaluation (ROSE) of samples obtained at the time of EUS-FNA. We have reviewed the role of ROSE, performed by the same endosonographer, a cytotechnologist and an expert cytopathologist. The available data suggest that ROSE (either by the endosonographer, the cytotechnologist, or the cytopathologist) improves sample adequacy and diagnostic yield, with the best option to have ROSE performed by an expert cytopathologist. However, if non-ROSE accuracy is already very high, any improvement is harder to achieve.