Rosen's Breast Pathology, 4e

899

Unusual Clinical Presentation of Carcinoma

Fibroadenoma The morphology of carcinomas that arise in FA is not pe­ culiar to this setting, but the relative frequency of the types of carcinoma differs from that of carcinomas found in

non-fibroepithelial breast parenchyma. In published reports, more than 50% of the affected FA had lobular carcinoma in situ (LCIS) 99,100 (Fig. 33.2). Among patients who were treated by mastectomy, LCIS was found in the surrounding

A

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C

FIG. 33.2.  Fibroadenoma, lobular carcinoma in situ. A: The epithelial component of the fibroadenoma is ex- panded by LCIS ( right ). B,C: LCIS does not extend beyond the border of this fibroadenoma with edematous stroma and sclerosing adenosis. D: LCIS involving an area of tu- bular adenosis in another complex fibroadenoma. E: Much of the epithelial element of this fibroadenoma is greatly expanded by LCIS.

E