Usual ductal hyperplasia

Usual ductal hyperplasia (UDH) is a benign lesion of the breast wherein cells look very similar to normal. It is a spectrum of changes that can range from minimal stratification of cells to proliferations that are just short of atypical ductal hyperplasia.

Histopathology
Usual ductal hyperplasia is typically a cohesive proliferation with haphazard, jumbled cell arrangement or streaming growth pattern. Cells have mild variation in cellular and nuclear size and shape.