Frozen section during surgery: what it decides in theatre

A frozen section is a fast examination of tissue while you are still asleep on the operating table. A piece is rushed to the laboratory, frozen solid, sliced and read under a microscope within about half an hour. The answer can change what the surgeon does next in that same operation.

Why it is done during surgery

Some decisions cannot wait for the full report that takes several days. The commonest is whether cancer has reached the first lymph nodes. If it has, the surgeon may need to do more to the armpit there and then, rather than bringing you back for a second anaesthetic weeks later.

Why it is not used for everything

Freezing distorts tissue. The slices are thicker and harder to read than the ones made from properly processed tissue, so fine detail is lost. It answers a blunt question quickly. It cannot replace the careful report that follows.

It cannot give you your stage, your grade, your receptor results or your margins. Families sometimes wait outside theatre expecting the whole picture within the hour. That is not what this test is for.

The result can change later

A frozen section reported as clear is sometimes found to contain a small deposit on the final report. This is not an error. The rapid slices simply cannot show what fully processed tissue shows, and everyone involved knows that when they rely on it.

What happens if it changes

If the final report finds something the rapid test missed, your team decides whether anything further is needed. Often the answer is treatment after surgery rather than another operation. It is worth asking what your surgeon would do in that situation, before the day.

Fewer centres use it for nodes now

Practice has moved. Because many women with one or two involved sentinel nodes no longer need the armpit cleared at all, the rapid answer changes less than it used to. If your team does not offer it, that usually reflects current thinking rather than a lack of facilities.