This is a needle biopsy from a pancreatic head mass. What is your diagnosis?
Answer: Pancreatic Acinar Cell Carcinoma
Comment: The trypsin expression is stronger in the acini than in the neoplasm. It is easy to mistake these neoplasms for pancreatic ductal adenocarcinoma if the diagnosis is not considered. Similarly, it is easy to confuse these tumors with neuroendocrine neoplasms. To compound the mimicry, acinar cell carcinomas can express synaptophysin. The best marker is probably BCL10 (not depicted).
Case was provided Dr. Elizabeth Montgomery, Editor-in-Chief of the Pathology Survival Guides at Innovative Science Press, and professor of pathology and Vice Chair of Anatomic Pathology at the University of Miami.
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