This document discusses benign breast diseases. It begins with an introduction that defines benign breast diseases as a heterogeneous group of lesions including developmental abnormalities, inflammatory lesions, epithelial and stromal proliferations, and neoplasms. It then summarizes some of the most common benign lesions seen in clinical practice and discusses their relationship to developing subsequent breast cancer. The document provides detailed information on the classification, diagnosis, and management of various benign breast conditions.