I was first told that after successful treatment in 2019/2020 I had HER2 back in a lymph node in my armpit. I was told it was a recurrence but was then told it was metastatic breast cancer. Can anyone tell me the difference because it was in my nodes initially.
This definitely doesn't fit the description of metastatic cancer. I would say this is a local recurrence, as it's in your armpit lymph nodes, where it was before.
Metastatic would be if it had found it's way elsewhere in your body, such as lungs, bone, liver etc.
Have a look at the information here: https://breastcancernow.org/information-support/facing-breast-cancer/diagnosed-breast-cancer/your-primary-cancer-has-come-back-recurrence
Hope this helps.
What treatment have they suggested? Have you had a PET-CT or MRI scan?
If the only recurrent cancer is in the lymph nodes in your armpit, I would have thought they'd want to remove all of the lymph nodes in that chain (clearance), This could remove all the cancer, and prevent it from spreading.
I say "could" as it's impossible to say whether cancer cells have made it into the blood stream and might be trying to set up shop elsewhere.
This would likely be accompanied by some form of hormone or chemo treatment to stop the latter from happening.