What you and @colely say is true but a needle core biopsy is not always the corrects answer. A pet scan is pretty definitive for a survivor who has a much higher anxiety about a “probable” than the a non survivor might.
I had a lump the size of a walnut sticking off of my chest wall and the mammogram came back as negative. 14 cores from a needle core came back negative, my surgeon says “well there is something there and I think we should just cut it out”. Grade 3, estrogen positive, her2 positive invasive ductal carcinoma.
All of this to say, no one procedure is always right, I hope you have a doctor you trust, and build that relationship by asking questions and weighing the recommendations. Then ask for what you need.
I am glad you are following through, do you have another appointment with this doctor? Is the lesion big enough to survive a core biopsy? Should it be excised? Pet scan?