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Non-melanoma skin cancer

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Grades of non-melanoma skin cancer

Grading is a way of classifying non-melanoma skin 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 non-melanoma skin 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 – tend to grow quickly, more likely to spread


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

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


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