Figure 2.

(a) Tumor cells form a papillary and conglomerate mass. Individual tumor cells have a round to short spindle-shaped nucleus with granular chromatin (Papanicolaou stain, original magnification ×400). (b) Individual tumor cells have a round to short spindle-shaped nucleus with granular chromatin. Nuclear atypia is not prominent. Some tumor cells show ill-defined rosette formation (Papanicolaou stain, original magnification ×1000). (c) Some tumor cells remain as separate cells rather than forming a mass. Many of these tumor cells contain cytoplasmic mucin. There are no prominent nucleoli (Papanicolaou stain, original magnification ×1000).