There are five common types of benign, or non-canerous, kidney tumours, all of which are asymptomatic. In many cases, benign renal tumours are not life-threatening; however, they can still cause issues if they become too large.
The most common type of benign kidney tumour is renal adenoma. According to the American Cancer Society, these are small and slow-growing tumours. They are difficult to distinguish between renal cell carcinoma and are typically treated as if they were renal cell cancer.
Oncocytoma tumours grow rather large in size. Oncocytoma kidney tumours can sometimes be mistaken for renal adenomas, and are typically treated as such. Additionally, oncocytoma tumours are typically seen more in men than in women.
Angiomyolipoma is a genetically inherited form of kidney tumours. Most individuals that are diagnosed with angiomyolipoma are also diagnosed with a rare inherited disease called tuberous sclerosis. Tuberous sclerosis can cause tumours throughout the body, not just on the kidney.
Fibroma tumours are tumours of the tissue. They are more common in women than in men.
Lipoma tumours grow within the fat cells and the surrounding tissue. They typically grow large and because of their size they become painful. They are more common in women than in men.