Electron microscopic and immunoelectron microscopic demonstration of pancreatic polypeptide cells in glucagonoma: colocalization of pancreatic peptide and glucagon in single secretory granules

• Published in: Ultrastructural pathology Vol. 13; no. 1; p. 15
• Main Authors: Ooi, A, Katsuda, S, Nakanishi, I, Kameya, T, Yamaguchi, K, Kitamura, H, Hayakawa, Y
• Format: Journal Article
• Language: English
• Published: England 01.01.1989
• Subjects: Adenoma, Islet Cell - pathology; Aged; Cytoplasmic Granules - immunology; Cytoplasmic Granules - metabolism; Cytoplasmic Granules - ultrastructure; Female; Glucagon - immunology; Glucagon - metabolism; Glucagonoma - metabolism; Glucagonoma - pathology; Glucagonoma - ultrastructure; Humans; Immunohistochemistry; Microscopy, Electron - methods; Pancreatic Neoplasms - metabolism; Pancreatic Neoplasms - pathology; Pancreatic Neoplasms - ultrastructure; Pancreatic Polypeptide - immunology; Pancreatic Polypeptide - metabolism
• ISSN: 0191-3123
• DOI: 10.3109/01913128909051156

We describe a case of pancreatic tumor in a 65-year-old woman with typical glucagonoma syndrome. Plasma glucagon (GL) and pancreatic polypeptide (PP) were markedly elevated up to 1404 and 1200 pg/ml, respectively. Histologic examination of the metastatic tumors in liver and lymph nodes showed endocrine-type tumors composed of GL-positive cells some of which coexpressed PP immunoreactivity. Electron microscopy revealed the tumor cells with single-type secretory granules similar to normal A cell granules. Double immunogold staining demonstrated both GL and PP immunoreactivities in the same secretory granules. Biologic and diagnostic significance of coexpression of PP and GL in a single secretory granules of pancreatic endocrine tumors is discussed briefly.