Drawing of the histology of a pituitary adenoma from an acromegalic woman

The specimen was hardened in alcohol and embedded in paraffin. The section was stained with hematoxylin and eosin. "The uniformity of all the cells which make up the growth and their close resemblance to the chromophilic cells of the normal [anterior pituitary] would seem to indicate that the adenoma originated from the chromophilic cells alone. The granular cytoplasm is well shown in the drawing, as is also the active response of these granules to the eosin." (A) Thin-walled blood vessel, filled with red cells; (B) connective tissue stroma enclosing a small blood vessel. (Source: Brooks H. Acromegalia. Arch Neurol Psychopathol 1898;1[3]:485-678. Plate VI, figure 2.)