[The immunohistochemistry of pituitary adenomas]

A great deal of progress has been achieved in recent years in the field of immunohistochemistry of pituitary adenoma. Continued use of more new antisera and monoclonal antibodies against numerous hormones in the adenohypophysis have resulted in new approaches to classification of pituitary adenoma. However, new problems have been discovered, on the other hand, by large-scale studies in recent years. The great number of multihormonal pituitary adenomas and possible change of the immunohistochemically detectable hormone status in cases of recurrent tumours have particularly re-emphasised the need for new thinking about patterns of classification. It would appear somewhat problematic, in this context, to uncritically accept terms, such as ACTH cellular adenoma or GH cellular adenoma. Reference is also made to the distribution pattern of cell and tissue markers in pituitary adenomas. The paper is based on thorough literature screening as well as on experience obtained by the authors from 450 cases of pituitary adenoma of which 260 had been analysed by immunohistochemistry, 131 by morphometry, and 80 by electron microscopy.