Pancreatic tumors trypsin

DAs are typically negative for pancreatic enzymes such as trypsin, chymotrypsin, and lipase °76 unless there is a mixed acinar component, which is uncommon. They also fail to label with endocrine markers however, in 30% of DAs there are scattered, possibly non-neoplastic, endocrine cells in close association with the neoplastic cells, which can be highlighted with immunostains for chromogranin A, synaptophysin, and NSE.2 2 77-79 latter two markers can occasionally show more diffuse expression, which should not be regarded as evidence of neuroendocrine differentiation if the tumor is an otherwise conventional adenocarcinoma. 

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