Topic overview

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Hyperpituitarism most often arises from a pituitary adenoma that secretes prolactin, growth hormone, ACTH, TSH, or gonadotropins. The hormone involved shapes the presentation: prolactin excess can disrupt reproductive function, while excess GH is associated with gigantism in children or acromegaly in adults, and excess ACTH causes Cushing disease. Expanding lesions may also produce mass effects, and sudden hemorrhage into an adenoma can cause pituitary apoplexy. Hypopituitarism reflects substantial gland damage or hypothalamic failure, with causes including nonfunctioning macroadenoma, postpartum pituitary necrosis, trauma, radiation, and empty sella. The lesson organizes these disorders by cause, manifestations, diagnostic approach, and treatment, while highlighting clinical clues that help distinguish hormone deficiency from tumor-related effects.