Endoscopic ultrasound (EUS) is paramount in the diagnosis and evaluation of cancers involving the gastrointestinal tract. EUS allows for the acquisition of cellular (fine needle aspirate - FNA) or tissue biopsy (fine needle biopsy - FNB) for diagnostic purposes. This has traditionally been done with fine needle aspirate where a needle is inserted into the tumor and potentially malignant cells are extracted for microscopic analysis. More recently, a needle that allows a tissue biopsy for histologic analysis has been FDA approved.
We will compare tissue samples obtained by standard FNA to FNB with a sample size of 140 patients with the primary outcome being diagnostic yield. Each patient will be randomized to FNA or FNA. If after 3 passes the on-site evaluation remains inadequate, the endoscopist will crossover to the other arm.
