Thank  猪猪 and 天山望月 for above data.

I agree that no clear definition for benign and malignant AME. Can some one do a literature search to see if there are some papers to describe the difference of the lesions?

 There are many cases in this website. It is meaningless if we see the photos and give a guess diagnosis. It is easy to have many classic pictures for all lesions in the text books, CD et al.

The advantage here online is that you can think over the differential dx, summary the cases, discuss the cases and share your oppinion with all others. We all are participants, not only readers.

 Quickly review above interpretation from all of you. It is good almost all of you got the correct point. Clearly it is a adenomyoepithelial lesion, two cell component.

Adenomyoepithelioma (AME) of the breast is an uncommon tumor characterized by the presence of both epithelial and myoepithelial cells; its first full description was published in 1970 by Hamperl.

Could some one sumarry the features of benign and maligant AME? I have not check books or literatures yet. So In fact I am not clear about the definition now. Hope some one will do the search and share with us here. Thanks, cz

 Thank  天山望月's detailed analysis. This is AFIP case. age about 50, tumor size 1.5 cm. IHC showed myoepthelial cell proliferation.

 50 y/f with breast mass lesion 2.5  cm.

1-2 40x

3-4 200x

5-6 400x