This monograph on the "Ultrastructure of Human Sella Tumors" is in fact a study of the correlations of clinical findings and morphology. It is a timely and eagerly awaited publication because of the increasing interest of the endocrinologist in pituitary disorders and of the neuro surgeon in the newest aspects of surgery on pituitary tumors, and also because of the unsatisfactory but still widely accepted classification into eosinophil, basophil and chromophobe pituitary adenomas. This old classification has been mainly based on granule color as seen after hematoxylin-eosin staining, but it...