A 35-year old woman makes an appointment at your clinic beca…
A 35-year old woman makes an appointment at your clinic because she is concerned about a lump she has found in her right breast. It first appeared 3 months ago. It changes with her menstrual cycle and is tender to touch. She does not have a family history of breast cancer. On physical examination, you inspect the skin, noting the absence of dimpling or retraction. Palpation of the breast reveals a round, 2-cm, freely mobile, tender, circumscribed mass that is firm in consistency and somewhat elastic. The patient has no axillary, supraclavicular, or infraclavicular adenopathy. What is your most likely diagnosis before proceeding with further testing?