Background: We sought to define the diagnostic yield and concordance rates between endoscopic ultrasound (EUS)-fine-needle aspiration (FNA) and surgical pathology specimen following resection of pancreatic neuroendocrine tumors (pNET) less than 2 cm. Methods: Patients with a pNET less than 2 cm who underwent EUS-FNA were identified using a multi-institutional international database. Tumor differentiation, and Ki-67 index, as determined through EUS-FNA were examined and concordance rates between EUS-FNA and the surgical pathology were assessed. Results: Among 628 patients with a pNET less than 2 cm, 57.2% of patients had an EUS-FNA performed. Patients who underwent EUS had slightly smaller size tumors (1.3 vs 1.4 cm), and the pNETs were less likely to be functional (15.3% vs 26.8%) or symptomatic (48.5% vs 56.5%) (both P <.05). Among 314 patients with a pNET less than 2 cm who had an EUS-FNA performed at the time of diagnosis, 243 (73.2%) had the diagnosis confirmed by preoperative EUS-FNA. Tumor differentiation and Ki-67 could be determined by EUS-FNA in only 26.4% and 20.1% of patients, respectively. Concordance rate between EUS-FNA and pathology was high relative to tumor differentiation (92.7%) and Ki-67 (81.0%). Conclusion: Tumor differentiation and Ki-67 index could be determined by EUS-FNA in only 26.4% and 20.1% of cases, respectively. Further studies should focus on EUS techniques to optimize diagnostic yield and cell extraction in the preoperative setting.

Additional Metadata
Keywords 2 cm, clinical relevance, EUS-FNA, pNET
Persistent URL dx.doi.org/10.1002/jso.26158, hdl.handle.net/1765/129563
Journal Journal of Surgical Oncology
Citation
Heidsma, C.M. (Charlotte M.), Tsilimigras, D.I. (Diamantis I.), Rocha, F. (Flavio), Abbott, D.E. (Daniel E.), Fields, R.C, Smith, P.M. (Paula M.), … Pawlik, T.M. (2020). Clinical relevance of performing endoscopic ultrasound-guided fine-needle biopsy for pancreatic neuroendocrine tumors less than 2 cm. Journal of Surgical Oncology. doi:10.1002/jso.26158