A non-mass breast cancer would be DCIS or LCIS. In both of these cases the diagnosis will be made by calcifications seen on the mammo. For me in these cases the job is to hunt down the calcifications as if you can reliably find them with a high degree of certainty, we can use ultrasound to perform a core biopsy. If we cannot find them they will have to use mammo guidance. I have never performed a “blind biopsy”, for me to be involved I must identify an area of breast tissue on the ultrasound that is suspicious and we target that area. I think there is a role to be played by blind breast biopsy when there is a clinical palpable abnormality and the imaging is all negative. If the breast surgeon feels the clinical abnormality is suspicious even in the presence of normal imaging a “clinical blind biopsy” of the palpable area is warranted. It is a simple admission that ultrasound and mammo cannot see all breast cancers and a clinical examination performed by a breast surgeon is still a very valuable piece of the diagnostic jigsaw.