Hypopituitarism

Abstract

Hypopituitarism refers to a complex medical condition characterized by the deficiency of one or more of the hormones of the pituitary gland. Its prevalence is around 45 cases per 100,000 individuals. There are numerous causes of hypopituitarism, with sellar (e.g., pituitary adenoma) and perisellar tumors being the commonest etiologic factors, along with the sequelae generated by the different therapeutical modalities employed towards its resolution, such as surgery and radiotherapy. Clinical presentation may have a broad spectrum depending on cause and age of onset, and may vary from chronic/subacute nonspecific general ill feeling and mass effect related symptoms, as it commonly occurs with space-occupying sellar masses, to an acute and life-threatening presentation, such as that seen in pituitary apoplexy. Diagnostic approaches towards identifying the etiologic factors and each hormonal axis deficiency (i.e., GH, LH/FSH, TSH, ACTH, and ADH), as well as the description of the different available schemes of hormone replacement therapy, are thoroughly reviewed in this chapter.