Canadian Cancer Society logo

Bile duct cancer

You are here: 

Grades of extrahepatic bile duct cancer

Grading is a way of classifying extrahepatic bile duct cancer cells based on their appearance and behaviour when viewed under a microscope. To find out the grade of a tumour, the biopsy sample is examined under a microscope. A grade is given based on how the cancer cells look and behave compared with normal cells (differentiation). This can give the healthcare team an idea of how quickly the cancer may be growing and how likely it is to spread.

The grade of extrahepatic bile duct cancer is based on the degree of differentiation of cells and their rate of growth.



well differentiated or low grade – slow growing, less likely to spread


moderately well differentiated or moderate grade


poorly differentiated or high grade – tend to grow quickly, more likely to spread

Extrahepatic bile duct cancers are usually slow growing.

Grading plays an important part in planning treatment for extrahepatic bile duct cancer and can also be used to help estimate the prognosis (future outcome).


Paul Newcombe Volunteering during Daffodil Month is an incredibly rewarding experience, whether you have been touched by cancer or not.

Read Paul's story

How can you stop cancer before it starts?

It's My Life! icon

Discover how your lifestyle choices can affect cancer risk and how you can take action with our interactive tool – It’s My Life!

Learn more