Approximately 10 years have elapsed since the first volume of the International Life Sciences Institute (ILSI) Monographs on Pathology of Laboratory Animals, Endocrine System was completed. New information of interest to pathologists has developed at a rather remarkable pace during the intervening years. Exceptional progress has been made in the routine identification of cell products in endo crine cells. A better understanding has developed of the mechanisms involved in cell metabolism, particularly involving toxins and car cinogens. Clear concepts have developed concerning the significance...