Pituitary tumors may present with symptoms of pituitary hypofunction, excess hormone secretion, or symptoms directly related to the mass effect of the tumor.

Magnetic resonance imaging is the best method for visualizing hypothalamic-pituitary anatomy.

Up to 20% of normal individuals harbor incidental pituitary tumors, which are almost all microadenomas.

A limited biochemical workup for asymptomatic patients with microincidentalomas, to include measurement of prolactin (PRL) and insulin-like growth factor-1 (IGF-1) is reasonable, with further studies to be tailored based on the clinical picture.

While pituitary adenomas are the most common cause of hypopituitarism, other causes, including parasellar diseases, inflammatory disorders, those following pituitary surgery or radiation therapy, and head injury, also must be considered.

Prolactinomas are the most common secretory pituitary tumors. They account for approximately 30% of all clinically recognized pituitary adenomas.

A serum PRL level >100 µg/L is usually indicative of a PRL-producing pituitary tumor.

A serum PRL level <100 µg/L in the presence of a large pituitary adenoma is suggestive of stalk compression. Some medications including metoclopramide and antipsychotics may be associated with hyperprolactinemia up to 250 µg/L.

Although patients with microprolactinomas can sometimes be followed without therapy, patients with macroprolactinomas must be treated.

A random growth hormone (GH) level is inadequate to establish the diagnosis of acromegaly.

IGF-1 has a longer plasma half-life than GH and is an excellent initial screening test for those suspected of acromegaly.

Current medical therapies for acromegaly include dopamine agonist, somatostatin analogs, and GH receptor antagonist.