A 39-year-old man with galactorrhea and a bitemporal hemianopia is most likely diagnosed with what?

In this scenario, the patient presents with galactorrhea and bitemporal hemianopia. Galactorrhea, which is the inappropriate secretion of breast milk, is often associated with elevated levels of prolactin. The most common cause of hyperprolactinemia is a prolactinoma, which is a benign pituitary tumor that secretes prolactin.

Bitemporal hemianopia, the loss of peripheral vision in both eyes, is commonly caused by a mass effect on the optic chiasm, which can occur with pituitary tumors due to their location just above the chiasm. The combination of these symptoms makes hyperprolactinemia the most likely diagnosis, as the prolactinoma leads not just to elevated prolactin levels, causing galactorrhea, but also to visual disturbances from the pressure it exerts on surrounding structures.

Other options such as Cushing's syndrome, pheochromocytoma, or hypoparathyroidism do not typically present with this specific combination of symptoms. Cushing's syndrome may also involve a pituitary adenoma but presents primarily with symptoms related to cortisol excess, which do not include galactorrhea or visual disturbances of this nature. A pheochrom