Macroscopic on-site quality evaluation of biopsy specimens to improve the diagnostic accuracy during Endoscopic ultrasound (EUS) guided fine needle aspiration (FNA) using a 19-gauge needle for solid lesions: a multicenter prospective randomized controlled study

All aspects of the study will be discussed with each subject when approached by study staff. An information sheet will be provided, and each subject will be given the opportunity to seek medical advice or to discuss the study with friends or family prior to involvement. Each volunteer will give written, informed consent, in accordance with the attached form, and the subjects will be free to withdraw from the study at any time. All patients who are referred to the principle investigator for EUS FNA will be seen in outpatient clinic for the procedure and will also be approached for the current study. All patients will be given information about the study and the agreement of participation in the study will be clarified on the day of the procedure. The patients will have the opportunity to raise any issues with the study by the provided phone number or in person on the day of procedure (prior to the procedure). All patients will undergo standard preparation for EUS and will be kept nil per oral for 6 hours before procedure. EUS would be performed under conscious sedation or monitored anaesthesia. The lesion, including the regional vasculature, would be examined by EUS using the colour Doppler function to locate a site suitable for FNA. The lesion would then be punctured with a 19G Nitinol needle under EUS guidance. On site cytopathologic assessment would not available in any of the cases. Macroscopic on-site evaluation (MOSE) would be performed by the following technique. EUS-FNA would be performed with a 19-gauge needle. The lesion is punctured and the needle is moved to and fro approximately 3-5 times within the lesion under 10cc of suction. After each pass, the needle is removed and the stylet would be introduced into the needle to extrude any aspirated material on a glass slide for inspection of the presence of a macroscopic visible core (MVC). MVC is defined as whitish or yellowish pieces of tissue with an apparent bulk. Paste-like or liquid-like specimens would not be included. The total length of the MVC is measured with a ruler before placement into a formalin bottle. When a MVC of 4mm or more is obtained, EUS-FNA is completed. If the obtained MVC is less than 4mm, then another pass of the lesion with the 19-gauge needle repeated. The procedure is repeated for a maximum of 7 passes until a MVC of 4mm or more is obtained. Any remaining partially paste-like material after removal of MVC’s would be sent in a separate formalin bottle for histology; liquid material will be fixed in alcohol and sent for cytological analysis. Adequacy of this additional cytological material would not be macroscopically assessed. One dedicated pathologist in each hospital will evaluate the obtained samples in terms of quantity (Grade 0: scant; Grade 1: inadequate; Grade 2: adequate), quality (Grade 0: poor; Grade 1: moderate; Grade 2: good), and blood contamination (Grade 0: significant; Grade 1: moderate; Grade 2: low), and provide a pathological diagnosis. The final diagnosis would be based on the followings: 1. Surgical specimen for resectable cases. 2. Positive FNA diagnosis for malignancy with a compatible clinical course. 3. Negative FNA diagnosis for malignancy with a lack of deterioration or spontaneous resolution on radio-logical studies with a minimum clinical follow-up time of 3 months. All staff for this study participating in this study have been trained and understand the study protocol, and will report any adverse events to the Human Research Ethics Committee within 24 hours.