Distinctions between the contrasting pairs of diseases are presented in capsule and table form by emphatic telegraphic statements. Photomicrographs in color of contrasted diseases that differentiate impressively the histopathologic features are presented at scanning, intermediate, and high magnification. Clinical photographs in color permit a reader to visualize the condition in the gross, an advantage that is particularly beneficial to a pathologist. The discussions that follow the tabulated points and counterpoints elaborate first on histopathologic attributes that each pair of contrasted diseases has in common, and then on correlation between the appearance of the diseases histopathologically and clinically, the usual clinical course of them, and, last, the histopathologic differential diagnosis.