Right, they are not worried about the cyst. They were at first when they saw it on the mammogram and didn't know it was a cyst but now that they do, (from the ultrasound), they are no longer worried. But what did not show up on the mammogram, and they only saw upon doing the ultrasound, is another much smaller lesion at 12'clock. They don't think, or know it is not a cyst and which means it could be anything else, and that includes both other benign and/or cancerous causes. So, this is what they are checking out through a biopsy because they cannot know from the ultrasound or mammogram. (the latter it didn't even show up)
You have a right to be worried and I think anyone would be. The unknown is often the hardest to take.
You just have to survive until next Wednesday and I know it's hard. Perhaps, if you get too anxious, or already are, you should ask for a tranquilizer. I think your doctor would understand.
Best wishes, kat
There is some kind of lesion that they need to biopsy to be sure its not cancer.