FIG 2. Case 1. Photomicrographs.

A, Large cells with nuclei display prominent nucleoli that diffusely infiltrate the pituitary gland (hematoxylin-eosin, original magnification x200).

B, The lymphoma cells are reactive for LCA and stain darkly, in contrast with the normal entrapped pituitary cells (arrowheads) (CD45 immunohistochemical stain, original magnification x100).