The separate lesion located at the 11:00 position 1 cm from the nipple was characterized by mostly benign breast tissue with apocrine metaplasia
, apocrine cysts, and focal ectatic ducts.
Benign cells of NDPs include normal duct cells, ductal cells exhibiting apocrine metaplasia
, histiocytes, and varying numbers of inflammatory cells.
17) Apocrine metaplasia
of epithelial cell component, as well as squamous and sebaceous metaplasia may be variably present.
Papillary apocrine metaplasia is a common papillary lesion that is associated with breast cysts.
1) Apocrine metaplasia can be found in the epithelium lining breast cysts as well as in papillomas and adenomas.
Localized apocrine metaplasia is generally not a feature of papillary intraductal carcinomas, although rarely, complete apocrine differentiation may be present, called apocrine papillary intraductal carcinoma.
Aside from apocrine metaplasia, which is rather common in papillomas, squamous, mucinous, clear cell, and sebaceous metaplasia may also occur at much lower frequency.
The adjacent breast parenchyma showed focal fibrocystic changes (sclerosing adenosis, simple dilated cysts, apocrine metaplasia
, and dense fibrosis).
Both antibodies only stained lymphocytes and occasional breast ducts, all showing apocrine metaplasia
As noted above, apocrine metaplasia
may involve or arise in papillomas, radial scars, and sclerosing adenosis.
Carter and Rosen (7) reviewed 51 cases of atypical apocrine metaplasia
in sclerosing lesions and reported that none of the 47 women with intact breasts (4 women had misdiagnosis and subsequent mastectomy) developed breast carcinoma within the average follow-up period of 35 months (12-76 months).
Benign lesions include lactational change, lactational adenoma, juvenile papillomatosis with apocrine metaplasia
, collagenous spherulosis, and cystic hypersecretory hyperplasia (Figure 3, A).