Mostly it is a mucinous ca. Of casue it is difficult to evaluate the case with only a few photos. As dr. qianxun mentioned above benign mucocele like lesions should be excluded.

WHO: the pure mucinous ca can be called if mucinous component should account for more than 90%. Some book uses the cut-of 75%. In fact in our practice we call pure mucinous ca only for the cases with 100%  mucinous component. Otherwise we will call ductal ca with xxx% municous component. The prognosis of pure mucinous ca is good.

 同意粘液腺癌，后几张图片砂粒体样结构，没有见过，翻了一下书，“细胞非典型性、核分裂和微钙化不常见，可偶见。”

谢谢

  Everyone is confident.  I am not.  Why not mucocele like lesion?