This study will focus on two key theories: the development theory of the breast fascia system and the reverse development theory. The research findings indicate that breast development generally follows a growth pattern from anterior to posterior, and from central to peripheral regions. However, an intriguing phenomenon contradicting this developmental process was discovered through endoscopic mastectomy, which has not been previously discussed. Based on the aforementioned theoretical analysis, this study includes patients who underwent endoscopic and reduction mammaplasty in the Department of Breast Surgery in the Sixth Affiliated Hospital of Sun Yat-sen University. The investigators proposed the following research framework: firstly, comprehensively understanding the structure of the breast fascia and the sequence of breast development through endoscope and existing research; secondly, exploring the relationship between breast fascia development and surgical processes by repeatedly observing surgical videos of endoscopic mastectomy and reduction mammaplasty; lastly, proposing a reverse development theory for breast fascia based on these theories in order to provide standardized and procedural guidance for breast surgeons.

Inclusion Criteria:

• Breast cancer patients who need mastectomy and patients who need breast reduction during the study period.

Exclusion Criteria:

• breast conserving surgery

Inpatients of Breast Surgery in the Sixth Affiliated Hospital of Sun Yat-sen University.

The corresponding database has not been established yet.