At EUS, once the pancreatic mass is identified, patients will be randomized to undergo sampling using the 22G FNA or FNB needle. All patients will undergo sampling of pancreatic masses using both needles but the needle to be used first will be based on randomization. Subsequent passes will be performed by alternate needles and once onsite diagnosis is established using either needle type, more passes will not be performed for onsite diagnostic adequacy. However, a minimum of at least one pass and a maximum of 8 passes will be performed using both needle types. The number of passes needed to achieve diagnostic adequacy using both needles will documented.
Four dedicated passes will then be performed using the initial randomization sequence for cell block. Two passes will be performed using each needle type and the specimen will be preserved in formalin and sent for cell block processing.
If the doctor cannot obtain enough tissue with the study needles, another needle with a different gauge (19 or 25) will be used. This will also be a maximum of 8 passes. Information about the number of needles used, how many passes were performed, any problems with the needles will be collected. If there is not enough tissue available from these passes to establish a diagnosis, the subject will be asked to come back at another time for a repeat procedure.
