What is a frozen section?

Sometimes we cannot be certain whether a lump seen on a scan is cancer or not. A frozen section is used to get a fast answer and plan the best operation, but this can only be done during surgery. During surgery the lump is removed and sent to the laboratory, it is frozen and looked at under the microscope. A specialist doctor in the laboratory can tell if it is cancer or not and call the surgeon with the result. The surgeon then continues with the best operation depending on the result. This process adds about 30 minutes to the operation time. When you are awake you will be told the result of the frozen section and which operation you needed.

In general if the frozen section shows a lump is not cancer, a wedge resection is usually the best operation. If the lump is cancer a lobectomy is usually the best operation. Results about spread of a cancer take more time and will be discussed in clinic, including whether results show chemotherapy may be helpful.

A frozen section may also be used to check that there are no cancer cells left directly next to where the tumour has just been removed. If the laboratory tells us there are still cancer cells present we can usually remove a little more tissue.

This test does not tell us if cancer cells have spread to another part of the body.