Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Renal oncocytoma ?
    ### Response:
    What causes a renal oncocytoma? The exact underlying cause of most renal oncocytomas is unknown. However, researchers suspect that acquired (not present at birth) changes in mitochondrial DNA may play a role in the development of some of these tumors. Renal oncocytomas sometimes occur in people with certain genetic syndromes such as tuberous sclerosis complex and Birt-Hogg-Dube syndrome.
    