Letter after Initial Consultation

I received my letter this morning with a precis of the events of the consultation.  I wasn't sure if the mammogram had shown up the lesion but apparently not.  Its not palpable either but did show up on the ultrasound.  I am not even sure if the CT scan picked up this particular lesion although I do know that cysts were picked up on the CT scan (the CT radiologist had spotted what he thought was a fibroadenoma and had recommended I had it investigated)  and mammogram. Makes you wonder how long it might have been there, certainly wasn't there in October 2020 when I had an ultrasound and cyst aspiration in the same breast.  Had I not had the fallen off the horse, I would be none the wiser and it would not have been picked up at my mammogram screening which would have been due in a few months.  Quite scary. What is this elusive lesion?