Breast carcinoma arising from sclerosing adenosis: a clinicopathologic and immunohistochemical analysis of 106 cases

Abstract

<h3>Backgrounds</h3> To elucidate the features of breast carcinoma (BC) arising from sclerosing adenosis (SA). <h3>Methods</h3> 106 BCs arising from SA were collected. Their clin-icopathological characteristics were examined and immunohisto-chemical staining was performed. <h3>Results</h3> (1) The average age of 106 females was 49.4 years. Fifty-nine cases were from the left breast, and 39 from right, 8 bilateral. Only 43 patients have breast masses. (2) Ninety-four (88.7%) cases were carcinoma in situ (CIS), including 75 DCIS, 13 LCIS, 5 mixed DCIS-LCIS, and one CIS showing both ductal and lobular features. Twelve (11.3%) cases were well-differentiated invasive carcinoma, including 8 cases of NOS, one case showing apocrine features and 2 ILC. Distorted glands in CIS were entrapped in fibrous/hyalinized stroma, with inconspicuous myoepithelial cells, mimicing invasive carcinoma. (3) Luminal A, luminal B, basal-like and Her2 overexpression phenotype was identified in 57, 19, 12, 6 cases of CIS, respectively, and 6, 4, 1, 1 cases of invasive cases, respectively. <h3>Conclusions</h3> BC arising from SA was rare. Low-intermediate grade DCIS was the predominant type; luminal A type was the most frequent. Histological appearance of CIS may resemble invasive carcinoma; over-diagnosis should be avoided. To be familiar with this entity is essential to accurate diagnosis and treatment.