EUS-guided fine needle biopsy (FNB) sampling and FNA are important methods for obtaining core tissues and cytologic aspirates. To improve the specimen quality for pathologic evaluation, a novel EUS-FNB Shark Core (SC) needle has been designed to acquire core tissue during EUS procedures. We compared the histology yield of EUS-FNB sampling using the SC needle (EUS-FNB-SC) to EUS-FNA in patients who had solid pancreatic and nonpancreatic lesions.

This was a retrospective case-control study design. Between July 2012 and July 2015 all patients who had EUS-FNB-SC and EUS-FNA were reviewed through a hospital EUS database. Consecutive samples from EUS-FNB-SCs were matched in a 1:3 ratio by lesion site (eg, pancreatic head) and needle gauge (ie, 19 gauge, 22 gauge, 25 gauge) to recent random samples of EUS-FNA. The procedures were performed with rapid onsite evaluation. For study purposes specimen slides were evaluated by 2 cytopathologists for histologic yield using a standard scoring system (0 = no material, 1-2 = cytologic, 3-5 = histologic). The main objectives were to assess the histologic yield of the samples and compare the median number of passes required to obtain core tissue by using EUS-FNB-SC and EUS-FNA needles.

Of the 156 patients included in study, 25% patients (n = 39) were in the EUS-FNB-SC group and 75% (n = 117) in the EUS-FNA group. According to standard scoring criteria for histology, the median histology score for EUS-FNA was 2 (sufficient for cytology but not histology) and for EUS-FNB-SC was 4 (sufficient for adequate histology). Ninety-five percent of the specimens obtained from the EUS-FNB-SC group were of sufficient size for histologic screening, compared with 59% from the EUS-FNA group (P = .01). The median number of passes required to achieve a sample was significantly lower in the EUS-FNB-SC group compared with the EUS-FNA group (2 passes vs 4 passes, P = .001). There was significant difference in the median number of passes to all lesion sites and needle gauges.

The histology yield was significantly higher using the EUS-FNB-SC needle compared with the EUS-FNA needle. Additionally, fewer passes were required to obtain histology cores when using EUS-FNB-SC.