RESUMO
During pregnancy, the body undergoes a major adaptation process as a result of the interaction between mother, placenta and fetus. Major anatomical and histological changes are produced in the pituitary, with an increase of up to 40% in the size of the gland. There are wide variations in the function of the hypothalamus-pituitary-thyroid axis that effect iodine balance, the overall activity of the gland, as well as transport of thyroid hormones in plasma and peripheral metabolism of thyroid hormones. The incidence of goiter and thyroid nodules increases throughout pregnancy. The management of differentiated thyroid carcinoma should be individually tailored according to tumoral type and pregnancy stage. Given the effects of hypothyroidism on fetal development, both the diagnosis and appropriate therapeutic management of thyroid hypofunction are essential. The most important modification to the hypothalamus-pituitary-adrenal axis during pregnancy is the rise in serum cortisol levels due to an increase in cortisol-binding proteins. Although Cushing's syndrome during pregnancy is infrequent, both diagnosis and treatment of this disorder are especially difficult. Adrenal insufficiency during pregnancy does not substantially differ from that occurring outside pregnancy. However, postpartum pituitary necrosis (Sheehan's syndrome) is a well-known complication that occurs after delivery and, together with lymphocytic hypophysitis, constitutes the most frequent cause of adrenal insufficiency. The management of prolactinoma during pregnancy requires suppression of dopaminergic agonists and their reintroduction if there is tumoral growth. Notable among the neuropituitary disorders that can occur throughout pregnancy is diabetes insipidus, which occurs as a consequence of increased vasopressinase activity.
RESUMO
Hypophysitis are a group of inflammatory lesions affecting the pituitary gland and pituitary stalk. These lesions should be included in the differential diagnosis of sellar masses. There are three types of primary hypophysitis: lymphocytic, granulomatous and xanthomatous. Lymphocytic hypophysitis is the most frequent form of chronic pituitary inflammation and is believed to have an autoimmune origin. This form characteristically affects women during the peripartum, with diverse types of pituitary deficiency, especially ACTH deficiency, and frequently there are other associated autoimmune processes. Lymphocytic hypophysitis can affect the anterior pituitary only, the infundibular stalk and posterior lobe of the pituitary (infundibuloneurohypophysitis), or the entire pituitary (panhypophysitis). Clinically, lymphocytic hypophysitis can manifest with compression symptoms, hypopituitarism, diabetes insipidus or hyperprolactinemia. The imaging technique of choice is magnetic resonance imaging, which helps to characterize the sellar lesion. Treatment includes replacement of the functional pituitary deficiency and the use of corticosteroids, generally at high doses. Surgical treatment is reserved for patients unresponsive to conservative therapy. Granulomatous hypophysitis can be of known etiology, whether infectious (currently highly infrequent) or non-infectious (ruptured Rathke's cyst, etc.). Granulomatous hypophysitis of unknown etiology is manifested by the presence of idiopathic granulomas. Xanthomatous hypophysitis is characterized by a histiocytic infiltrate with cystic characteristics on imaging. Secondary hypophysitis is due to pituitary inflammation caused by surrounding lesions or can form part of systemic diseases.