Figure 1.

Examples for CD56 staining (Immunoperoxidase ×400). A) Strong expression of CD56^Pan in nearly all tumor cells in a unrelapsed case, B) Weak reaction with the same antibody in only few tumor cells of a relapse (4^th relapse of another case), C) Expression of CD56^{140/180 kDa} in a relapse, and D) Strong expression of the same in nearly all tumor cells of its primary.