Pituitary adenoma medical therapy

Overview
Pituitary adenomas are tumors that occur in the pituitary gland, and account for about 10% of intracranial neoplasms. They often remain undiagnosed, and small pituitary tumors are found in 6 to 24 percent of adults at autopsy. Pituitary adenomas arise within the anterior lobe (adenohypophysis) of the gland. Tumors less than 1 cm are called micro adenomas. Clinical symptoms depend on whether the tumor is secreting or nonsecreting. Nonsecreting adenomas grow and compress adjacent structures, most commonly causing a bitemporal hemianopsia due to chiasmatic compression. Lateral extension into the cavernous sinuses can result in cranial nerve palsies.

Medical therapy
Treatment options depend on the type of tumor and on its size:
 * Prolactinomas are most often treated with bromocriptine or more recently, cabergoline which, unlike bromocriptine, decreases tumor size as well as alleviates symptoms, both dopamine agonists, and followed by serial imaging to detect any increase in size. Treatment where the tumor is large can be with radiation therapy or surgery, and patients generally respond well. Efforts have been made to use a progesterone antagonist for the treatment of prolactinomas, but so far have not proved successful.
 * Thyrotrophic adenomas respond to octreotide, a long-acting somatostatin analog, in many but not all cases according to a review of the medical literature. Unlike prolactinomas, thyrotrophic adenomas characteristically respond poorly to dopamine agonist treatment.