Tumors of the liver, extrahepatic biliary tract, and pancreas

Electron microscopy can be of limited value in distinguishing among poorly differentiated hepatocellular carcinomas, bile duct carcinomas, and other adenocarcinomas, but may be very helpful in identifying tumors that are metastatic to the liver. The characteristic ultrastructural features of endocrine and exocrine tumors of the pancreas are readily distinguished by electron microscopy when the tissue is adequately preserved, and this technique can be very useful in establishing a diagnosis.