Mo1279 YIELD OF THE 22G FRANSEEN TIP CORE BIOPSY NEEDLE INSTEAD OF A STANDARD EUS-FNA NEEDLE IN 125 SELECTED “DIFFICULT” EUS TISSUE SAMPLING CASES

Abstract

The yield of EUS tissue sampling using a standard FNA needle for epithelial cancers is generally >90%. However, there are cases where standard FNA needles perform poorly (ex: SMTs, linitis, autoimmune pancreatitis, chronic pancreatitis, well-differentiated cancers, etc.). We hypothesized that selective use of the Franseen tip core biopsy needle might improve the diagnostic yield in these “difficult” cases. When the 22g Franseen tip needle became available at our institution, we began to selectively use it for the following indications: 1) failed previous EUS-FNA, 2) atypical mass (possible met, differentiate NET from adenoca, etc.), 3) suspected GIST, 4) suspected linitis, 5) suspected AIP, 6) indeterminate mass in chronic pancreatitis, 7) suspected lymphoma. EUS-guided biopsy was performed with no stylet and no suction, with a multi-pass fanning technique, by one of 2 experienced endosonographers. Samples were expressed into formalin using air. Additional passes were performed as needed, after visual assessment of specimen adequacy, without ROSE. Analysis was performed on intent to sample basis. Between 12/15/2016 and 11/10/2017, 615 lesions were sampled. 125 cases (20.3%) met our criteria for Franseen tip needle biopsy: 102 masses [56% pancreas, 20% GI wall, 17% retroperitoneal, 7% liver, 1% mediastinum] and 23 nodes [78% retroperitoneal, 22% mediastinal]), mean diameter 31±22mm [median 25mm], mean # passes 2.2±1.2 [range 1-5]. The prevalence of malignancy was 77%. Adequate samples for histological analysis were obtained in 115/125 (92%). In 5/10 (50%) inadequate samples, long term follow up showed true negatives. Sensitivity for malignancy was 91.7%, negative predictive value 78.4%. There were no immediate complications. In selected difficult EUS tissue sampling cases, the 22g Franseen tip needle: 1) Provides samples adequate for histological analysis in 92%, 2) The sensitivity for malignancy is 91.7%. These results were obtained without ROSE. The 22g Franseen tip needle is an excellent choice in cases where traditional EUS-FNA results are inadequate, and ROSE is not required.