TSH, free thyroxine (free T4 )
Femaleb : estradiol, progesterone
Morning ACTH Fasting am cortisol 24-hour urine free cortisol Dexamethasone suppression test
Morning growth hormone
Prolactin a Test results may be altered by pharmacological agents.b Tests should be performed and related to normal values for timing of menstrual cycle.
infectious causes of problems, including sarcoidosis, histiocytosis X, bacterial meningitis, tuberculosis, or abscess, are typically resolved by the presence of other findings of these diseases. Lymphocytic hypophysitis and Sheehan's syndrome often occur in the peripartum. Finally, one must always be vigilant to detect prescription or recreational drugs that interfere with normal pituitary function.
Evaluation. X-ray examination of the skull is of limited use in the evaluation of the patient with a suspected pituitary adenoma. CT scanning with bone windows is usually selected first, but this may miss a very small adenoma. MRI with contrast enhancement defines the soft tissue characteristics and is more sensitive to tumor identification in patients with large tumors. Angiography may be necessary to define the arterial supply for surgical planning and to exclude the presence of aneurysm. Neuro-ophthalmological evaluation for accurate mapping of visual disturbances is important prior to surgery. Evaluation of pituitary function is needed in all patients ( Table.,46-5 ). All patients require evaluation for cortisol insufficiency, especially to guard against cortisol insufficiency postoperatively.
Management. Prolactin-secreting tumors can be managed with the use of dopamine agonists such as bromocriptine (0.5 to 2.5 mg/day). These drugs interfere with the dopaminergic pathways between the hypothalamus and the pituitary. Ketoconazole has been proposed to stop the effects of ACTH hypersecretion. Use of somatostatin for GH-secreting tumors is still under investigation. Surgery remains the best way to produce a definitive diagnosis. The typical surgical pathway is a transsphenoidal approach and is usually curative. Use of radiotherapy (including stereotactic radiation) remains effective for patients with evidence of recurrence and for those who are not surgical candidates or who have not benefited from postsurgical medical intervention. After surgery, patients remain at risk for visual field defects or pituitary insufficiency, including panhypopituitarism requiring hormonal supplementation.
Prognosis and Future Perspectives. Because of the success of surgical intervention, these tumors have a very favorable prognosis. Recurrence is usually confined to patients in whom resection is incomplete. Further refinements in the medical treatment for microadenomas may allow nonsurgical treatment throughout life in some patients.
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