43, 44, 45, 74, 63. APOCRINE CYSTIC METAPLASIA (APO cysts). A POSSIBLE INDICATOR OF INCREASED RISK.
LEGEND
Slides 43, 44, 45, 74, and 63. Apocrine metaplasia arises almost exclusively in the TDLU, not in the larger duct systems. Although cancers of the apocrine type are rare, and there is no evidence that apocrine metaplastic cells are especially preneoplastic, the presence of numerous apocrine cystic lobules (APO cysts) is indicative of genetic and phenotypic instability in the mammary gland, and therefore an indicator of increased risk for the development of mammary cancer. The upper far left subgross image is of a TDLU completely replaced by apocrine cystic metaplasia. The lesion measures 3 mm in greatest dimension. The left middle histological image is a low magnification of the same lesion, and the right middle a higher magnification. Note the pink apocrine cells and the granular secretion. The secretion is frequently calcified and heavy enough to settle to the bottom of the cysts, forming cresents ("teacups") recognizable to the mammographer. The "teacups" change orientation according to the position of the patient, and the radiographic appearance is highly diagnostic of benign cyst. The subgross image to the far right is an example of 5 mm apocrine cystic lobule with entering terminal duct. The histological image at the bottom right shows both epithelial hyperplasia and apocrine metaplasia in terminal ducts. These are the smallest and earliest lesions of these kinds which we have found. Hematoxylin stain.
Last Updated: August 24, 1997
Back to First lecture page.
Back to lecture image page
Back to Main Transgenic Page
Back to Top of Page