LCIS in Sclerosing Adenosis
LCIS may be present in benign proliferative lesions such as fibroadenomas, papillomas, radial sclerosing lesions and sclerosing adenosis (shown in this image). When present in sclerosing lesions, LCIS distorts the lobular configuration and it is difficult to rule out invasion in such foci. However, in sclerosing lesions, the glandular units are surrounded by a basement membrane, myoepithelial cells and stroma. These components can be highlighted by reticulin stain, immunostains for laminin and type IV collagen, and myoepithelial markers. The presence of intracytoplasmic mucin supports LCIS. In addition, LCIS will show loss of E-Cadherin - a feature not seen with benign proliferative lesions mentioned previously.