While a careful pathologist will wait for appropriate frozen or permanent tissue histologic examination, the description given in the question stem is most suggestive of fibrocystic disease. The fibrous pa of the lesion forms the dense, white tissue strands, while the blue lesions are what are called "blue-domed cysts". The blue color comes from the presence of darkly colored fluid (which usually means old hemorrhage) within the cyst. The interior cyst wall is usually smooth. These blue-domed cysts are a ourite of examiners because they produce a distinctive gross picture and should be specifically associated with fibrocystic disease, but you should be aware that in real life they do not occur with anything near the frequency of fibrocystic disease without obvious large cysts grossly (but many smaller cysts on microscopic examination). Fibrocystic disease of the breast is a very common lesion, and a frequent source of palpable lumps in the breast, which may require fuher evaluation through either excisional biopsy (as in this case), Tru-cut needle biopsy (producing a thin core about 1 cm long), or needle aspiration (producing fluid or cells for cytology). Also know: While a diagnosis of breast cancer should obviously be confirmed microscopically before telling the clinician, invasive breast cancer can be suspected when there is a hard, white, nodular area of the breast that has irregular (but often reasonably well-defined - in contrast to the fibrotic areas of fibrocystic disease) boundaries. The changes of pregnancy cannot be reliably picked up on gross examination of the breast. Fibroadenoma , like breast cancer, tends to produce a well-defined mass lesion, but it typically has smooth borders and may have a slightly gray and slightly mucoid (e.g., shiny or oily appearing) surface on cross-section. Ref: Chandrasoma P., Taylor C.R. (1998). Chapter 56. The Breast. In P. Chandrasoma, C.R. Taylor (Eds), Concise Pathology, 3e.