Fortnightly Review: Diagnosis and management of pituitary tumours

Pituitary tumours are mostly benign epithelial neoplasms that result from mutation and subsequent clonal expansion of single adenohypophyseal parenchymal cells.1 They account for 10-15% of intracranial neoplasms, and three quarters of them secrete inappropriate amounts of pituitary hormones. Although residual cells in parasellar structures may account for local recurrences that follow seemingly complete surgical clearances, metastatic spread and direct macroscopic invasion of surrounding structures is fortunately rare.2 Most patients with pituitary adenomas present with symptoms and signs of hormone hypersecretion, visual field defects, headaches, and hypopituitarism either alone or in combination (see box 1). Preoperative diabetes insipidus is extremely rare in primary pituitary disease and suggests involvement of the hypothalamus or pituitary infarction. Any visual disturbance can occur - from changes in the lateral fields that a patient typically finds hard to describe and which may go unrecognised for years to scotomas and complete blindness in one or both eyes. Many patients complain of vague peripheral shadows confined to the upper quadrants. Headaches are usually non-specific - annoying more than disabling and frequently helped by analgesia. In some patients they are relieved almost immediately by somatostatin or somatostatin analogues, only to recur as the peptide is cleared from the circulation. If panhypopituitarism is suspected (see box 2 for typical features) glucocorticoids should be replaced before thyroid hormones. #### Box 1 - Typical presenting feature pituitary adenomas #### Box 2 - Typical features of hypopituitarism Hypogonadism ##### Women ##### Men ##### Hypoprolactinaemia ##### Hypothyroidism ##### Growth hormone deficiency