Macro and Histological images. (a) Macro findings of an encapsulated solid tumor measuring 140 mm at its the greatest dimension. The cut surface was smooth with a pale yellow color, and showed numerous mucinous foci without extracapsular invasion. Microscopically, the tumor exhibited (b) Antoni A areas composed of ill-defined fascicles of spindle cells and (c) loosely organized Antoni B areas. (d) Immunohistochemically, the tumor cells were strongly positive for S-100 protein.