[Ultrastructural observations of human pancreatic duct cell carcinoma]

The great majority of human pancreatic duct cell carcinoma are thought to be of ductal origin and acinar cell carcinoma has been reported to be very rare. This paper reports electron microscopic observations of human pancreatic duct call carcinoma. The results were as follows. In the cases which were diagnosed as well or moderate differentiated adenocarcinoma of the pancreas by light microscope, three different types of tumor cells were observed by electron microscope. Two of them had characters of ductal cells. The origin of these tumor cells were considered to be originated from the relative large and small pancreatic ducts. Third type was a little different from cell types mentioned above. Some of these cells had swollen mitochondria and well developed rough endoplasmic reticulum with a various distribution of zymogen granules. Microvilli and cellular projects were scant. These findings were considered to be the dedifferentiation of the acinar cells and this type belonged to be acinar cell carcinoma.