Which tumor is associated with excessive epinephrine and norepinephrine production?

Pheochromocytoma is a tumor that arises from the chromaffin cells of the adrenal medulla, which are responsible for producing catecholamines, specifically epinephrine and norepinephrine. The excessive secretion of these hormones leads to symptoms such as hypertension, palpitations, and anxiety, often manifesting as episodes of "fighting or flight" responses.

This unique characteristic of pheochromocytoma—where the tumor leads to hypersecretion of catecholamines—distinctly sets it apart from other tumors listed. Adrenal adenomas may produce corticosteroids but are not typically associated with elevated levels of epinephrine and norepinephrine. Medullary thyroid carcinoma can produce calcitonin but does not affect catecholamines, and hepatocellular carcinoma primarily involves the liver and has no direct relation to catecholamine production. Hence, pheochromocytoma is the most appropriate answer, as it is the tumor directly tied to the increased production of epinephrine and norepinephrine.