Grading eye cancer
The grade is a description of how the cancer cells look compared to normal cells. To find out the grade of eye cancer, the pathologist looks at a tissue sample from the tumour in the eye under a microscope. The pathologist gives eye cancer a grade from 1 to 3 or 0 to 4 depending on the type of eye cancer. A lower the number means the cancer is a lower grade.
Your doctor doesn’t need to know the grade of the cancer to plan your treatment for eye cancer. They can plan treatment based on the results of other tests such as the eye exam and imaging tests. Grading isn’t done unless you have had a biopsy or surgery to remove tissue from the eye.
Knowing the grade gives your healthcare team an idea of how quickly the cancer may be growing and how likely it is to spread. This helps them plan your treatment. The grade can also help the healthcare team predict future outcomes (your prognosis) and how the cancer might respond to treatment.
Grading intraocular melanoma
The grade is a description of the type of cells found in the tumour. Intraocular melanoma is made up of spindle cells, epithelioid cells or a mix of both cell types.
Low-grade intraocular melanoma is made up of mostly spindle cells. These cancers tend to be slow growing and are less likely to spread. High-grade intraocular melanoma is made up of mostly epithelioid cells. These cancers tend to grow more quickly and are more likely to spread than low-grade cancers.
spindle cell melanoma (more than 90% spindle cells)
mixed cell melanoma (more than 10% epithelioid cells and less than 90% spindle cells)
epithelioid melanoma (more than 90% epithelioid cells)