Any one ever hear of something like this?

Hi all.  I do not fit in the concerned about a reoccurrence as of yet but I did not know where else to post this so I was hoping this forum would do the trick.  Here is my question/situation.  Backstory-I work for a state agency and when I returned to work after medical leave with my scarves and hats I was approached by several cancer survivors to swap stories.  One lady in particular I have formed a bond with and since she has no family I call and check in on her, see if she needs groceries, whatever.  She had BC originally about 30 years ago.  About seven years ago she was diagnosed with mets.  She has been on various chemos and herceptin since then.  For the most part she has been doing great, working, gardening, she is doing way more than most "healthy" 70 year olds.  Right before Christmas a scan showed a tumor, I am not exactly sure of placement, and she had to undergo surgery immediately.  They sent the tumor off to a new pathology lab, for them, in California and the results came back metastatic OVARIAN cancer, not BC. HUH?  I asked her if that meant both had metasticized and she said they told her no that it was not a recurrence of BC at all but was the ovarian cancer.  She never knew she had ovarian cancer.  So she then told me that they say they are going to keep treatment about the same but drop the Herceptin.  Am I missing something and there are other questions she should be asking?  How could doctors tell her for seven years she had BC mets and it was ovarian mets?  I really feel for this lady.  She told me that she was happy to be in the hospital for Christmas so that she did not have to be home alone.  Has anyone ever heard of the two getting confused before or is this malpractice in some form? It seems bizarre to me.