Most Kidney tumors today are detected incidentally when patients are undergoing x-ray studies for unrelated reasons. This is very fortunate as the cure rate for most of these accidentally small lesions is over 90%. Due to the location of the kidney deep in the back, symptoms usually do not develop until the tumor gets quite large. Moreover, these symptoms are often due to other benign causes and none are specific for a renal tumor. These symptoms include blood in the urine (visual to the patient or only with the microscope) and abdominal or back pain. Occasionally a mass can be felt in the abdomen. Some renal carcinomas can produce hormones that can cause symptoms such as high blood pressure, nausea, decreased appetite, fever and fatigue. These tumors can also cause abnormalities in liver tests, calcium level and blood count. It is important to realize that as of yet there is no specific blood test that can detect renal carcinoma.
Diagnosis and Staging:
Routine Screening for renal cancer is not recommended other than yearly urinalysis and blood work as well as a physical examination. Patients with a family history (multiple relatives) should consider screening X-ray studies.
When a renal tumor is detected, several tests are performed to help in diagnosis and staging of the tumor to help formulate the best treatment plan. Staging helps determine how extensive the tumor has grown locally and if it has spread to other parts of the body.
- 1 A Complete History and Physical Exam: This helps assess extent of tumor, how long it may have been present, possible causes and other known medical conditions that may impact upon treatment.
- 2 Blood work and Urinalysis: This lab testing helps assess the overall kidney function and gives clues to any evidence of spread of tumor or other unrecognized medical problems.
- 3 Imaging Studies: A renal ultrasound, computerized axial tomography (CAT) scan and magnetic resonance imaging (MRI) can all help in assessing the size and location of the tumor. These can also give information regarding any growth into surrounding organs or blood vessels as well as spread to lymph nodes or the liver. A chest x-ray is sufficient to assess for any spread to the lungs. A CT scan of the brain is not necessary unless neurological symptoms exist. Also, a bone scan is not needed unless there is new bone pain or elevation in a blood test. There is no test to determine with 100% certainty that any given renal tumor is cancer. Based on size and appearance one may be able to give a relative chance of a tumor being cancer. Unfortunately, biopsy is not helpful, as studies have shown that an error in diagnosis may occur in up to 28% of patients.
Tumor staging is defined by what is called the TMN system. This tries to define the extent of disease. T stands for the local growth of the tumor, N assess spread to local lymph nodes adjacent to the kidney and M assess if there is any metastasis. In general, Higher numbers are correlated with more advanced disease.
|T1||Tumor is confined to the kidney without growth through the capsule and is less than 7 cm|
|T2||Tumor is confined to the kidney without growth through the capsule and is greater than 7 centimeters|
|T3a||Tumor penetrates through the kidney capsule into the surrounding fat or the adrenal gland, but not through Gerota's fascia.|
|T3b||Tumor has grown into the renal vein or the vena cava. The tumor thrombus is below the level of the chest diaphragm.|
|T3c||Tumor has grown into the renal vein or the vena cava. The tumor thrombus extends above the level of the chest diaphragm.|
|T4||Tumor penetrates through Gerota's fascia.|
|Lymph Node Staging
|N0||No cancer in the lymph nodes|
|N1||Cancer in a single lymph node|
|N2||Cancer in more than one lymph node|