Technical feasibility, diagnostic yield, and safety of microforceps biopsies during EUS evaluation of pancreatic cystic lesions

Background and Aims: Through-the-needle microforceps are a recent addition to the EUS armamentarium for evaluation of pancreatic cystic lesions (PCLs). The main aim of this study was to assess the technical feasibility, diagnostic yield, and safety of EUS-guided microforceps biopsy for PCLs. Methods: Our electronic endoscopy database was queried to identify patients who underwent EUS-guided FNA (EUS-FNA) of PCLs and microforceps biopsies during the same procedure. A biopsy was done on the wall of the cyst with the microforceps through the 19-gauge needle, and cyst fluid was collected for cytology and carcinoembryonic antigen (CEA) levels. Adverse events were recorded per published American Society for Gastrointestinal Endoscopy criteria. Results: Twenty-seven patients underwent EUS-FNA and microforceps biopsy of PCLs from February 2016 to July 2017. Fourteen cysts were located in the pancreatic head and/or uncinate, and 13 were located in the body and/or tail region. Microforceps biopsies were technically successful in all cases and provided a pathology diagnosis in 24 of 27 cases (yield 88.9%). Microforceps biopsies diagnosed mucinous cyst in 9 patients (33.3%), serous cystadenoma in 4 (14.8%), neuroendocrine tumor in 1 (3.7%), and benign and/or inflammatory cyst in 10 (37.1%). In 7 patients (26%), microforceps biopsy results drastically changed the diagnosis, providing diagnoses otherwise not suggested by cytology or cyst fluid CEA levels. However, cytology provided a diagnosis of mucinous cyst in 4 cases (14.8%) not detected by microforceps biopsies. No adverse events were noted. Conclusion: Microforceps biopsies were associated with high technical success, and an excellent safety profile and may be a useful adjunctive tool, complementing existing EUS-FNA sampling protocols for PCLs.