What is a common early sign of a pituitary adenoma?

A common early sign of a pituitary adenoma is vision changes, particularly due to the tumor's location and its potential impact on adjacent structures, especially the optic chiasm. As the adenoma grows, it can exert pressure on the optic nerves, leading to visual disturbances such as bitemporal hemianopsia, where patients lose peripheral vision on both sides. This is particularly significant in the case of larger tumors.

While severe headaches, mood swings, and seizures can be associated with pituitary adenomas, they are not typically the initial presenting signs. Headaches may occur as the tumor increases in size and causes increased intracranial pressure, but they often appear later in the disease process. Mood swings may arise due to hormonal imbalances caused by the adenoma, but this effect might not be immediately recognized as related to a pituitary tumor. Seizures are less common and usually indicate a more advanced or severe case, often related to significant intracranial involvement. Thus, vision changes remain the most direct and early observable indicator of a pituitary adenoma.