Multiple hormone producing islet cell carcinomas of the pancreas. A morphological and biochemical investigation.

Biochemical, light, and electron microscopic studies of two multiple hormone producing metastic islet cell carcinomas of the pancreas are presented. Both tumors initially produced symptoms referable to a single hormone and over a period of years produced two other endocrine active polypeptides. The tumor in case 1 had been studied electron microscopically six years previously and had demonstrated no significant ultrastructural changes since then. The tumor in case 2 contained secretory granules of markedly varying size and density, suggesting a formation of packaged precursor molecules of possibly all three hormones. The pathogenesis of these tumors is discussed in light of recent evidence concerning the origin of endocrine cells.