OMG .... I was just thinking WELL DONE on being on Exemestane with no real side effects, then I read the next bit. :(

I am SO sorry to hear of your daughter's diagnosis.  Has Immunotherapy been raised as a form of treatment?  It is cutting edge, personalised treatment. 

There have been some posts on BCNA Metaplastic Breast Cancer ... @Michelle_R - can you help @Beb46

Please check this link:

https://onlinenetwork.bcna.org.au/search?Search=Metaplastic+Breast+Cancer

Personally, I've not heard of that particular Breast Cancer before, but below is a link to An Qld researcher in Metaplastic Breast Cancer. 

Research related to breast cancer classification and implications for clinical practice

Researcher: Dr. Sunil Lakhani, University of Queensland

Dr Lakhani recently published practice-changing findings that contributed to a new classification of a rare breast cancer, called Metaplastic Breast Cancer.

https://nbcf.org.au/news/new-guidelines-for-pathologists-to-identify-the-most-aggressive-forms-of-breast-cancer/

And an overseas link to 

Metaplastic Breast Cancer:

https://www.mpbcalliance.org/metaplastic-breast-cancer/

I hope you can get some answers that helps xx

Wishing you and your daughter all the best xxx