This specimen is moderately difficult, mainly because the actual source may receive less attention than other organs.Note that this is a solid organ (as opposed to a hollow or tubular one).
In the main region of this sample, at least three distinct types of tissue can be noticed even in this low-magnification image.
Also notice a small region with a distinctly different texture, attached to the main sample (arrow).
Hints on the next page are more revealing. Don't look until you are ready to confirm your identification.