Immunohistochemical characterization of an amphicrine mucinous islet-cell carcinoma of the pancreas. Case report

Immunohistochemical characteristics of a mucinous islet-cell carcinoma of the pancreas are described. The tumour presented with jaundice in a 59-year-old male. It consisted of polygonal atypical cells forming a reticular pattern, and invaded the common bile duct. In DNA flow cytometry, the tumour cells showed a clear-cut aneuploid peak. Intercellular mucin was abundant. A panel of antisera and monoclonal markers was applied in the immunohistochemical analysis. In addition to general epithelial and endocrine markers, the tumour cells showed a focal positive immunoreaction with anti-glucagon, anti-insulin, anti-vasoactive intestinal polypeptide, anti-pancreatic secretory trypsin inhibitor and anti-phospholipase A2 antigen. At the ultrastructural level, mucous and neuroendocrine granules were demonstrated in the same tumour cells.