Transsphenoidal surgery is the preferred mode of therapy for most pituitary tumors. Tumors of the pituitary gland generally present with clinical findings related to an endocrinopathy or mass effect. Symptoms of endocrinopathy include the Forbes–Albright syndrome (amenorrhea–galactorrhea), infertility, and decreased libido from hyperprolactinemia; acromegaly (Marie's disease) or gigantism from excessive growth hormone (GH); and Cushing's disease from excessive adrenocorticotropic hormone (ACTH) resulting in hypercortisolism. Symptoms of mass effect include visual deficits, cranial nerve palsies, hypopituitarism, headaches, or rarely, obstructive hydrocephalus or hypothalamic dysfunction. Tumors causing mechanical compression are usually hormonally inactive. Diagnosis is made by history, clinical examination, laboratory tests, and neuroimaging (MRI). Several therapeutic options are available, including pharmacotherapy, radiotherapy, and surgery. The goal of treatment is to return hormone secretion to normal, remove the tumor and correct any mass effect.

Pharmacotherapy

Pharmacotherapy is a therapeutic option for functional tumors. Bromocriptine (Parlodel) and cabergoline (Dostinex), both oral dopamine agonists, are the primary options for prolactinomas. These drugs shrink prolactinomas in approximately 80% of patients, but they are tumorostatic rather than tumoricidal. If therapy is withdrawn, the tumor resumes growth; therefore, therapy is typically lifelong. Another disadvantage is that these drugs may cause tumor fibrosis, which reduces surgical cure rates, especially if patients take them for more than one year. Side effects include nausea, dizziness, headaches, and postural hypotension. For acromegaly, the drug options include bromocriptine or cabergoline, the somatostatin analogues octreotide (Sandostatin) or lanreotide (Somatuline), and the GH analogue pegvisomant (Somavert).