Approach Considerations
Missed or delayed diagnosis of hypopituitarism could potentially lead to permanent disability or death. Medical care consists of hormone replacement as appropriate and treatment of the underlying cause. Glucocorticoid (cortisol) is required if the ACTH-adrenal axis is impaired. This is particularly important in sudden collapse due to pituitary apoplexy or acute obstetric hemorrhage with pituitary insufficiency. In such circumstances, do not delay initiation of a possibly lifesaving treatment pending a definitive diagnosis. Treat secondary hypothyroidism with thyroid hormone replacement. [4]
Treat gonadotropin deficiency with gender-appropriate hormones. In men, testosterone replacement is used and substituted with human chorionic gonadotropin (hCG) injections if the patient desires fertility. In women, estrogen replacement is used with or without progesterone as appropriate.
GH is replaced in children as appropriate. GH is not routinely replaced in adults unless the patient is symptomatic of GH deficiency, after all other pituitary hormones have been replaced. Then, a 6-month trial of replacement GH therapy may be considered.
Surgical care depends on the underlying cause and clinical state. In pituitary apoplexy, prompt surgical decompression may be lifesaving if head imaging reveals clinically significant tumor mass effect. Microadenomas do not need surgical treatment unless GH or ACTH hypersecretion is present. Prolactinomas, small and large, generally respond to medical therapy with tumor shrinkage and alleviation of mass symptoms. Debulk macroadenomas with mass symptoms that do not respond to medical therapy or are not expected to respond to medical therapy. Some asymptomatic nonsecreting macroadenomas may have an option of close clinical/radiologic observation. If radiotherapy is used, long-term new-onset hypopituitarism may occur and must be monitored.
The most common causes of nonsecreting pituitary adenomas are variants of gonadotropin-secreting tumors. In perhaps a third of these lesions, treatment with the potent dopamine agonist cabergoline may result in some decrease in mass or prevention of recurrence. [25]
A retrospective study by Graffeo et al indicated that in radiation-naïve patients receiving single-fraction stereotactic radiosurgery for pituitary adenoma, a mean gland dose of less than 11.0 Gy may reduce the likelihood of posttreatment hypopituitarism. The investigators found that in patients who received this lower dose, the rates of hypopituitarism at 2 and 5 years were 2% and 5%, respectively, compared with 31% and 51%, respectively, for those who received a mean dose of 11.0 Gy or higher. [26]
A study by Lee et al found that in patients with nonfunctioning pituitary adenomas, gross-total resection and/or adjuvant radiotherapy appear to prevent tumor recurrence or regrowth. The study involved 289 patients, 193 of whom had gross-total resection, 53 of whom had near-total resection, and 43 of whom had subtotal resection. [27]
A literature review by Li et al indicated that in the surgical treatment of pituitary adenomas, endoscopic transsphenoidal surgery is more successful than microscopic transsphenoidal surgery in gross tumor removal and, unlike the microscopic technique, does not significantly affect cerebrospinal fluid leak risk. Moreover, the endoscopic surgery significantly decreases septal perforation risk and is not linked to an increased risk for meningitis, epistaxis, hematoma, hypopituitarism, hypothyroidism, hypocortisolism, total mortality, or recurrence. [28]
In very ill hospitalized patients or in patients undergoing major procedures, stress-dose steroids are required and are quickly tapered to a maintenance schedule after the procedure. Minor procedures or illnesses may not necessitate a change in steroid dose or may require a simple doubling of the usual daily dose until the illness resolves. Other hormone replacements are continued at their usual maintenance doses as appropriate.
No special diet is necessary in patients with hypopituitarism unless dictated by an underlying disease process. Also, no activity restrictions are necessary unless dictated by an underlying disease process. Include an endocrinologist, a neurosurgeon, and a radiologist in consultations, as appropriate.
The World Health Organization's 2017 classification of pituitary tumors lists adenoma subtypes that may be more aggressive and likely to recur, requiring additional therapy. [29]
Prevention
Good obstetric care has reduced the incidence of postpartum hypopituitarism. Radiation therapy that minimizes exposure of the pituitary reduces the time of onset of hypopituitarism. Experienced neurosurgeons employing high-resolution microscopic hypophyseal surgery may reduce the likelihood of subsequent hypopituitarism.
Long-Term Monitoring
Provide long-term follow-up care for complications of underreplacement or overreplacement. Stressful situations warrant an adjustment in therapy. Unlike adults, children require GH replacement.
Follow-up care also involves adjusting hormone replacement to physiologic maintenance levels using the lowest dose. Monitor the patient to avoid overreplacement. The incidence of new neoplasms is increased in young people treated with GH who had previous tumor treatment. [30] This does not appear to be the case in adult patients. Excessive glucocorticoid or thyroid doses, or inadequate sex steroid doses, have been associated with decreased bone mineral density.
