<prompt> A 65-year-old woman is found to have a 1-cm mass in the upper outer quadrant of the left breast. The most likely cause isFibrocystic disease.Acute mastitis.Fibroadenoma.Carcinoma.  <response>: The location of the mass in the upper outer quadrant and the patients age of 65 years suggest that the breast lesion is a carcinoma. A breast mass in a postmenopausal patient is most often a carcinoma. 