Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) hereditary paraganglioma-pheochromocytoma ?
    ### Response:
    Hereditary paraganglioma-pheochromocytoma is a condition characterized by the growth of noncancerous (benign) tumors in structures called paraganglia. Paraganglia are groups of cells that are found near nerve cell bunches called ganglia. A tumor involving the paraganglia is known as a paraganglioma.
    