Evaluation of the SharkCore(®) needle for EUS-guided core biopsy of pancreatic neuroendocrine tumors

BACKGROUND AND OBJECTIVES: EUS guided core biopsy was once rarely performed but is now entering mainstream practice. Neuroendocrine tumors often warrant core biopsy as sufficient tissue must be obtained to allow for special staining to ensure a correct diagnosis. Traditionally these lesions were sampled with FNA needles. We performed a retrospective pilot study to evaluate the clinical value and efficacy of the a new EUS core needle biopsy needle as compared to a standard EUS FNA needle in the evaluation of patients with known or suspected neuroendocrine tumors. METHODS: A retrospective analysis of the first 10 patients (between January 2015 and April 2016) to undergo EUS-FNA with the SharkCore(®) needle at the University of Utah School of Medicine/Huntsman Cancer Center with neuroendocrine tumors. Each case was retrospectively reviewed by a board certified cytopathologist (BLW) for the following cytologic parameters on the aspirate smears or touch/squash preparations: overall cellularity [1 (low) to 3 (high)], percentage of obtained cells that were lesional/representative (<25%, 26%-50%, and >50%), relative ease of interpretation [1 (difficult) to 3 (easy)]. Pathologic material and reporting records were also reviewed for each case to confirm the number of needle passes to achieve diagnostic adequacy, the presence or absence diagnostic material on H&E slide (from cell block, if prepared), whether a definitive diagnosis was able to be rendered, and the presence or absence of a true core/core fragments (within the cell block, if prepared). RESULTS: A total of 20 patients underwent EUS-FNA for suspected neuroendocrine lesions. Ten patients underwent either transgastric or transduodenal EUS-FNA with the 22 gauge SharkCore(®) needle. The comparison cohort of 10 patients underwent either transgastric or transduodenal EUS-FNA with the standard 22 gauge Echotip(®) needle. The SharkCore(®) needle required a fewer mean number of needle passes to obtain diagnostic adequacy than the Echotip(®) (P=0.0074). For cases with cell blocks, the SharkCore(®) needle produced diagnostic material in 100% of cases, whereas Echotip(®) produced diagnostic material in 60% of cases. There was no significant difference between specimen cellularity, percentage of lesional material, or ease of interpretation between the two needle types. CONCLUSION: Our pilot investigation targeting patients with known or suspected pancreatic NETs indicates that the SharkCore(®) needle shows promise in obtaining suitable tissue for ancillary testing that can allow for more definitive pathologic interpretations on EUS FNA specimens. Fewer passes were needed with the core needle when compared to a standard needle.