After discussing the short functional anatomy of breast, common lesions of breast like mastitis, abscess, most common benign tumors like fibroadenoma and fibrocystic changes, and also number one carcinoma in female-breast carcinoma along with its risk factors, etiopathogenesis, classification, gross and microscopic features, diagnostic modalities and staging and grading are incorporated. Also rare tumors like phylloides tumor and immunohistochemical markers for diagnosis and management of Ca breast like ER, PR and HER/2 are described. Proliferative breast lesions with or without atypia, granulomatous, plasma cell mastitis are also mentioned.