What sort of doctor should i see first about a lump in my breast?

One that you trust.: Anyone that can order a mammogram and any appropriate follow-up tests. This would include primary care, general surgeon, plastic surgeon, ob/gyn or even am oncologist. In the event the diagnosis proves to be breast cancer the patient should always speak to both a general surgeon and a plastic surgeon to best understand their options. If mass proves not to be cancer follow-up as directed.

Primary Care Doctor: Depending on your age, the best place to start is with your pcp, whether that's your family physician, internist, gynecologist, or pediatrician. If necessary, they will order the appropriate test(s) and refer you to a breast surgeon. While not mandatory, it helps if your breast surgeon performs office-based ultrasound, so that the evaluation can be completed expeditiously.