A second opinion is definately in order, your consultation with the people at Mayo is a wise decision. Christine, the founder of this website, had a similar situation about 5 years ago, here is her story:
http://www.her2support.org/story2.htm
Neucrosis means that the tumor is dying, which may be happening in your situation. Send your phone number to:
joe@her2support.org , I will have Christine call you as she is very knowledgeable in this area.
Warmest Regards
Joe