Occurence and cytodifferentiation of mucopolysaccharide secreting cells in the pancreas of children with nesidioblastosis

Large numbers of mucopolysaccharide secreting cells were found in the pancreatic tissue of children with nesidioblastosis. Ultrastructural studies showed that mucus cells contained secretion granules and a characteristic smooth endoplasmic reticulum composed of an array of anastomosed tubules. The periodic acid - thiocarbohydrazide - silver reaction demonstrated the presence of glycogen in the hyaloplasm and of polysaccharides in secretion granules, the Golgi apparatus and in vesicles. A hypothesis is proposed, according to which mucus cells differentiate from a pancreatic stem cell common to both endocrine and exocrine tissues, through a mitochondria-rich intermediate cell stage.