Canadian Cancer Society logo

Eye cancer

You are here: 

Grades of eye cancer

Grading is a way of classifying eye 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 eye cancer is based on the degree of differentiation of cells and their rate of growth.

The following grading system applies to squamous cell carcinomas of the conjunctiva and sarcomas of the orbit.



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


moderately well differentiated or moderate grade


poorly differentiated – tend to grow quickly, more likely to spread


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

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


Ray Ellis in fireman gear Because of smoke inhalation and exposure to toxic chemicals, I live with the fear of cancer virtually every day.

Read Ray's story

Funding lifesaving clinical trials

Illustration of science instruments

The Canadian Cancer Society is funding lifesaving clinical trials that give people with cancer access to the newest types of treatment.

Learn more