PITUITARY-ADENOMAS - CLINICO-MORPHOLOGIC CORRELATIONS

Immunohistochemistry and electron microscopy allow new insight into the biology and natural history of the proliferative processes of the hypophysis. Hyperplasia can be diffuse or focal. Its function and/or growth are controlled by hypothalamic factors. Hyperplasia may precede the formation of an adenoma. Function and/or growth of adenomas is practically or completely independent of hypothalamic regulation. Adenomas are divided according to their functional activity into an endocrine active and inactive group. A further subdivision is made according to the secreted hormone. Inactive adenomas may have lost the ability to produce hormones, may secrete hormones at a very low rate, or may secrete abnormal substances.