Cytological findings and BCL10 expression in pancreatic acinar cell carcinoma: A Case Report

BCL10 was recently demonstrated to be a biomarker for pancreatic acinar cell carcinoma, but whether altered BCL10 expression can be detected in cell block specimens is unclear. Here, we report a pancreatic acinar cell carcinoma with cytological findings that showed BCL10 expression in a cell block. A 72-year-old man presented with a pancreatic tumor and underwent endoscopic ultrasound-fine needle aspiration (EUS-FNA) with additional passes performed for cell block preparation. The EUS-FNA cytology showed loose cohesive clusters with focal acinar- or gland-like-structures and prominent nucleoli. The preoperative diagnosis was well differentiated adenocarcinoma, and he underwent a pancreaticoduodenectomy. Histological examination revealed an acinar tumor structure with tumor cells staining positive for BCL10 and trypsin. The cell block specimen also demonstrated strong and diffuse BCL10-positive staining. Based on these findings, this tumor was diagnosed as acinar cell carcinoma of the pancreas. This case demonstrates that BCL10 expression within cell blocks facilitates a differential diagnosis of acinar cell carcinoma. Diagn. Cytopathol. 2017;45:247-251. © 2016 Wiley Periodicals, Inc.