Can pituitary adenomas cause a decrease in sense of smell due to hormonal imbalance? Which hormones are out of balance with hyposmia?

Not usually. Hormonal alterations based on resection of a pituitary adenoma do not typically cause changes in smell. However, there is a dependency on how an adenoma was removed; there is a small incidence of hyposmia with a endoscopic transsphenoidal surgerical approach.