Argyrophil cells in the urachal epithelium and urachal adenocarcinoma

Urachal adenocarcinoma, normal urachus, and urinary bladder were studied by histochemical methods and electron microscopy. Many argyrophil cells were found in urachal adenocarcinoma and urachal epithelium. Autofluorescence and immunoperoxidase examinations showed that the argyrophil cells possessed serotonin, glucagon, and secretin. Some of the carcinoma cells and urachal epithelial cells contained fairly large amount of mucosubstances. On the other hand, only a few argyrophil cells and very weakly PAS positive cells were observed in the urinary bladder mucosa. This study showed that there were close similarities in the histochemical and electron microscopical features between the urachal carcinoma and urachal epithelium, and suggested that the undifferentiated stem cells were able to differentiate to both glandular and endocrine cells.