EUS-FNA with stylet for Lymphadenopathy

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become an important tool in the diagnostic evaluation of gastrointestinal tract lesions and other organ sites such as mediastinal and intra-abdominal lymphadenopathy, pancreatic masses, liver masses, left adrenal masses and gastrointestinal submucosal lesions. It provides crucial information that can have tremendous impact on patient management. FNA is typically performed using a 22- or 25-gauge needle with a stylet under EUS guidance. The lesion is punctured with a stylet in place in the needle. After withdrawal of the stylet, the needle is moved to and fro within the lesion and this process is repeated for each needle pass. It is currently believed that the use of a stylet for EUS-FNA improves the quality of specimens by preventing the tip of the needle being clogged up with tissue and hence enhances the diagnostic yield of specimens obtained. However, there are no data demonstrating clearly that the use of a stylet improves the yield of EUS-FNA. The reason why this question is important is because the use of a stylet during EUS-FNA is cumbersome, time and energy consuming and increases the costs of EUS-FNA needle systems. In this prospective randomized controlled trial, patients referred for EUS-FNA of mediastinal and intra-abdominal lymphadenopathy, pancreatic mass, liver mass, left adrenal mass and gastrointestinal submucosal tumors will be included. FNA will be performed with a 22-gauge needle under EUS guidance using suction with a 10 mL syringe by two experienced endosonographers. The technique to be used for fine needle sampling i.e. with a stylet in place or without a stylet for each FNA pass will be assigned by using a preprinted randomization scheme obtained from a sealed envelope and clearly documented. Each lesion will be sampled for a minimum of four needle passes. The pathologists providing the final interpretation will be blinded to technique of EUS-FNA (with or without stylet). The degree of cellularity, contamination, amount of blood, adequacy of sample, frequency with which a positive diagnosis is made will be compared between the two groups (EUS-FNA with stylet vs. EUS-FNA without stylet). The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of each technique when compared to the final diagnosis will be calculated. Inter-observer agreement among cytopathologists will be assessed for specimens obtained from EUS-FNA with stylet and for those obtained from EUS-FNA without a stylet.