ABSTRACT
Immunocytochemistry has made enormous contributions to our understanding of the structure and function of the adenohypophysis, in both health and disease [1-5]. The technique is most often applied by the pathologist to the study of pituitary adenomas. As a result, the classification of this relatively common group of neoplasms has undergone total revision [6]. The groundwork for the latter was provided by utilizing polyclonal antisera, most of which are of rabbit origin. These continue in their popularity in diagnostic applications, despite the availability of monoclonal antisera to most pituitary hormones. By and large, the latter are intended not for immunocytology but rather for use in serum measurements. This stems from the extremely restricted specificity of many monoclonal reagents and concomitant "falsenegative" immunostaining results.
