Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been established as an effective technique for sampling tissue inside and around the gastrointestinal tract, including the pancreas, liver, lymph nodes, and adrenal glands. EUS-FNA is convenient, minimally invasive, and safe procedure with an estimated sensitivity of 75%-92% and a specificity of 82%-100%.

Diagnosis of various pathologies in the GI tract including solid pancreatic masses, mediastinal or gastric lymph nodes, gastrointestinal submucosal lesions, and peri-rectal lesions require adequate tissue architecture and immunohistochemical analysis. This is difficult to obtain and is frequently insufficient with EUS-FNA cytology alone. The core tissue is required to improve the diagnostic yield and obtain histologic diagnosis along with immunostaining to establish specimen adequacy. In past 1 year two new needle EUS needle (Shark Core)and Acquire EUS needles has been introduced to improve diagnostic accuracy, tissue yield, and potentially obtain a core tissue sample. So far, no prospective studies have compared these two needles to see which one is better for overall diagnostic accuracy. Our goal is to perform a prospective analysis to compare the diagnostic yield and safety profile of these 2 new EUS needle.

Subjects will come to a pre-procedure room on the day of the procedure. The investigator will again go over the risk and benefit of procedure and indication of the procedure. Once the consent form is signed, a large bore IV cannula is placed and the subject will be taken to the DHC procedure room. Once all the team members required to perform the procedure are in the room we will do a time-out to make sure current patient and procedure are performed. A time-out is done by asking the subject to tell his full name with date of birth and describe in his own words what procedure is planned for subject today. If all the things match the investigator will go ahead and start the sedation.

All EUS-FNB will be performed in the standard manner using linear echoendoscopes. All EUS-FNB procedures were performed by 1 of 2 highly experienced endosonographers (Henning Gerke or Rami EL-Abiad).

The needle to be used (SharkCore vs Acquire) will be decided based on randomization software. The needle will then be used to puncture the target lesion in standard fashion. Aspirated cellular materials will be expressed into the slide by advancing the stylet. The remainder will be expressed onto filter paper and submitted for cell block preparation. The subject's medical information including diagnosis, date of diagnosis, date of admission, blood test results, and medications received will be reviewed for analysis.

Inclusion Criteria:

• Patients schedule for EUS guided biopsy

Exclusion Criteria:

• Patients who had EUS-FNA for cystic fluid aspiration
• Pregnant females
• International normalized ratio >1.5 and platelet count < 50,000
• Medically unstable

We will not be sharing IPD.

1 year