Tubular Carcinoma vs Microglandular Adenosis
The differential diagnosis of tubular carcinoma (TCa) consists of benign entities like microglandular adenosis (MGA) and sclerosing adenosis (SA).
MGA consists of small uniform glands with open lumina scattered irregularly in adipose or fibrous tissue of the breast. Angular luminal contours of TCa are not seen. The epithelium of MGA is cuboidal with uniform height and pale cytoplasm. The glandular lumen contains eosinophilic secretions. Myoepithelial layer is absent in both TCa as well as MGA. However, MGA usually contains intact basement membrane that can be demonstrated by reticulin, laminin, or collagen IV stains. TCa usually lacks basement membrane. MGA is positive for S-100 protein and lacks ER and PR positivity. TCa is negative for S-100 protein and strongly positive for hormone receptors.