Because there are several types of kidney tumours, the doctor does a series of tests to better understand your specific situation. These tests include a medical history, laboratory tests and scans. Sometimes a family history is also taken. A CT scan or MRI scan will reveal the size of the tumour and if it has invaded local veins, lymph nodes, or surrounding organs. This is important to determine further treatment. The doctor may also perform a physical examination and take blood and urine for testing.
With the results of your scan, the urologist can define the stage of the disease. By analysing tumour tissue, received either during surgery or biopsy, the pathologist determines the subtype of the tumour and whether or not it is an aggressive form. Together, the stage, subtype, and aggressiveness of the tumour form the classification.
Classification of the kidney tumour is used to estimate your individual prognosis. Based on this individual prognosis your doctor will discuss the best treatment pathway for you.
In some cases you may need additional tests to check your kidney function. This is important if you only have one kidney or if you are at risk of kidney failure because you have diabetes, high blood pressure, chronic infections, or a kidney disease.
Imaging is important for the diagnosis and classification of kidney tumours. Most common imaging techniques are ultrasound, CT scans, and MRI. In some cases a biopsy is done to get more insight into the specific characteristics of the tumour.
After a tumour is detected, the doctor first needs to know whether it is malignant. A contrast-enhanced ultrasound, CT, or MRI scan of the abdomen and pelvis provides information about this. CT and MRI scans also show:
- The location and size of the tumour
- Whether or not you have enlarged lymph nodes
- Whether or not the tumour has spread to neighbouring organs, such as the adrenal gland, liver, spleen or pancreas
- Whether the urinary tract is affected by the tumour
For a contrast-enhanced scan, a contrast medium is administered through an IV, usually in your arm. The contrast medium highlights your veins and arteries by giving them a different colour in the pictures taken during the scan. This type of scan allows the radiologist to analyse the tumour. The results will guide the treatment you receive.
If you are allergic to contrast medium, you will receive an MRI or CT scan without contrast-enhancement.
If your doctor thinks the cancer may have spread to the lungs, you will get further tests, like a CT scan. You may need a bone or brain scan if you have symptoms such as bone pain or epileptic seizures. These scans are done to see whether the cancer has spread to bones or the brain.
Renal tumour biopsy
During a renal tumour biopsy, one or more samples of tumour tissue are taken. First, you receive local anaesthesia. Then the doctor inserts a needle through your skin and uses ultrasound or CT imaging to locate the tumour. The tissue samples are analysed by the pathologist in order to help determine future treatment.
Renal biopsy is not standard procedure in the diagnosis of kidney cancer. You may need a biopsy in case:
- The results of your scan are not clear enough
- You have a small tumour which could be treated with active surveillance
- You have a small tumour which could be treated with radiofrequency ablation or cryotherapy
Biopsies may cause blood in the urine. In rare cases, they can cause more severe bleeding. A renal tumour biopsy is generally a harmless procedure.