Diagnostic Evaluation of Usual Ductal Hyperplasia and Atypical Ductal Hyperplasia

Ductal hyperplasia of the breast is an intraductal proliferation of epithelial cells that is subdivided into two diagnostic categories: usual ductal hyperplasia and atypical ductal hyperplasia. Usual ductal hyperplasia represents a non-neoplastic proliferation that is commonly encountered as a component of fibrocystic changes. Atypical ductal hyperplasia, on the other hand, represents a neoplastic proliferation that shares cytologic and architectural features with ductal carcinoma in situ. Accurate differentiation between these two forms of ductal hyperplasia is important for patient management and breast cancer risk assessment.