Endocrine Abstracts

Tumours of the pituitary gland and sellar region represent approximately 15% of all brain tumours. The most common tumours are by far pituitary adenomas, confined to the sella. However, several types of tumours may involve the sellar region, reflecting its complex anatomy. The differential diagnosis of nonpituitary sellar masses is broad and includes inflammatory and infectious diseases, cell rest tumours, germ cell tumours, lipomas, gliomas, meningiomas, metastatic tumours, and vascular lesions. Nonadenomatous sellar lesions do not present with any hypersecretory syndrome but rather with neurologic or hypopituitary symptoms as a result of the mass-effect mechanism. Neurologic symptoms include headache, visual disturbance, cranial neuropathy, hydrocephalus, and mental changes. Hypopituitarism most often is characterized by growth hormone deficiency and gonadal dysfunction, followed by secondary hypothyroidism and adrenal insufficiency. Hyperprolactinemia secondary to stalk compression is a common cause of hypogonadism. Diabetes insipidus is highly suggestive of nonadenomatous sellar lesions, especially in sarcoidosis and in metastatic sellar involvement. For most of these tumours, surgery is first choice intervention. Resolution of headaches and amelioration of visual field defects occur shortly after surgery in the majority of patients. The recovery of visual fields is progressive, with an early fast phase of improvement during the first week after surgery, an early slow phase (4–6 months postoperatively) by the end of which most of the eventual recovery takes place and a late phase (up to 3–5 years) in which mild further improvement may still occur. Regarding pituitary function, in most but not all series, normalization of one or more hypothalamo-pituitary-axis function has been reported after surgery, whereas worsening of pituitary function is less common. The degree of improvement is variable. Patients in whom tumour has been completely excised usually are follow-up in an expectant way. In contrast, the best management of patients in whom residual tumour is detected on postoperative MRI is controversial, and may include surgery, radiotherapy, and medical therapy namely the use of dopamine agonists.