A kidney tumour can feel frightening — but not every kidney mass behaves the same way. Most are discovered incidentally, during a scan done for another reason entirely, and many are slow-growing.
How kidney masses are assessed
Assessment starts with a careful review of your imaging – CT, MRI or ultrasound – alongside blood tests of kidney function. Some patients need a biopsy to confirm the diagnosis; many do not. Complex cysts are graded using the Bosniak classification, which guides whether surveillance or treatment is appropriate.
Not every tumour is cancer
Around 10–20% of small kidney masses turn out to be benign – oncocytomas and angiomyolipomas among them. Even confirmed renal cell carcinoma spans a wide spectrum of behaviour, which is why treatment ranges from active surveillance through ablation to kidney-preserving partial nephrectomy.
What happens next
If you have been told you have a kidney mass, bring your imaging to a specialist review. A clear plan – surveillance, ablation or surgery – should always be a shared decision, made with full understanding of your options.
