Kidney puncture biopsy is not necessary for a definitive diagnosis of kidney cancer. This is because a puncture biopsy of a kidney tumor is usually not that accurate – it has the potential to falsely suggest that the tumor is benign when in fact it is the opposite, and puncture is, after all, an invasive test with some operative risks, such as causing bleeding and organ damage.
Also, some benign renal tumors, such as pheochromocytoma, are very similar to renal cancer under the microscope, so it is difficult for pathologists to clarify the nature of the tumor by giving them only such a small portion of the tissue for puncture biopsy, and even very experienced pathology professors would be powerless to do so. Therefore, to make a final determination of benignity or malignancy, it is still necessary to send the whole tumor for pathological examination after the surgeon has removed the tumor completely, and finally the pathologist will make an accurate diagnosis.
So for most patients, if a CT scan indicates that the tumor is likely to be malignant, then the patient should be treated surgically according to the criteria for malignancy without the need for a kidney tumor aspiration biopsy. Renal tumor puncture biopsy should be used primarily in the following situations:
- Patients who wish to be actively monitored for small renal occupancies;
- to clarify the pathologic diagnosis prior to ablative therapy;
- Clear pathologic diagnosis prior to targeted therapy or radiotherapy.
Puncture can be performed under ultrasound or CT guidance. The cost of a renal puncture biopsy includes the cost of the puncture operation, puncture equipment, anesthesia, nursing care, and pathology testing, with a total cost of about $5000 to $10,000.
The diagnostic rate of a single renal puncture biopsy is about 80%, so most patients need only one renal puncture biopsy, and if the pathologic diagnosis is not clear, repeat punctures or surgical procedures to obtain tissue samples for pathologic examination are required.