Tissue biopsy

A biopsy involves removing a tissue sample for examination under a microscope. It is a common way to diagnose cancer, but it is not often needed for kidney cancer before treatment. This is because imaging scans are good at showing if a kidney tumour is cancer.

For many people with kidney cancer, the main treatment is surgery. In this case, the tumour removed during surgery is tested to confirm that it is cancer.

A biopsy may be done before treatment when:

• surgery is not an option because the tumour is very small and active surveillance is suggested – a biopsy will help work out what other treatment is needed
• the tumour is large, looks irregular on the scan, or has obviously spread to the renal vein, adrenal gland or nearby lymph nodes.

If a biopsy is done, it will be a core needle biopsy. For this procedure, you will have a local anaesthetic to numb the area, and then an interventional radiologist will put a hollow needle through the skin. They will use an ultrasound or CT scan to guide the needle to the kidney and remove a sample of tissue. The procedure usually takes about 30 minutes.

The tissue sample will be sent to a laboratory, and a specialist doctor called a pathologist will look at the sample under a microscope to check for any cell changes.

In some cases, a kidney tumour will turn out to be benign (not cancer). Benign kidney growths, including oncocytoma and angiomyolipoma, can cause problems, and treatment may be similar to the treatment for early kidney cancer.

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