It is interesting case, but it is very common in our breast clinic. The tumor shows some features of invasive lobular ca, but E-cad is obvious positive (membrane stain).

The diagnosis of ductal or lobular ca for this case depends on your diagnostic criteria. Will you use morphology or e-cadherine for your classification. In the US most pathologists use E-cadherine for classification (positive for ductal ca, negative for lobular ca). People think E-cad stain is more objective.

We will call this case as invasive ductal ca without any doubt.

No reason to call mixed tumor for this case.

I think morphology and E-cad stain are the same in all areas.

Good point.

Agree

 本人认为：低分化的浸润性导管癌。

如方便时还可做IHC：CK5/6,β-Catenin及CK34βE12，小叶癌前两项均不表达，后项表达（+）；而浸润性导管癌则反之。

对乳腺癌我科常规免疫组化中E-cadherin和CK34βE12是配套一起做，一般均可区别小叶癌和导管癌（特殊病例除外）。