Removal of the renal mass, removal of part of the kidney (partial nephrectomy) or even removal of the whole kideny (nephrectomy) can be done by minimally invasive techniques. Requirements for pain relief is sometimes less with these minimally invasive techniques. There are good medicines to relieve post-operative pain.
Many biopsy techniques are percutaneous/ needle based. With many biopsy techniques, a positive result confirms the presence of the lesion, but a negative result does not rule out the lesion. It is for these reasons, many urologists would, when dealing with a mass they think is suspicious for a malignancy, prefer to remove it.