Abstract: Abstract： Objective To investigate the clinical application of mammotome minimally invasive techniques for benign breast mass, and the risk factors of residual tumor. Methods A total number of 722 patients with benign breast mass re⁃ ceived treatment of mammotome minimally invasive operation. Skin incision length, peeling times, blood loss and operation time were recorded. The complications after surgery, the difference of constitution ratio in different BI-RADS grades, mass number, mass volume and clinic features were analysed. The Logistic repression analysis was used to analyze risk factors of mass residue. Results The average skin incision length was (6.25±1.92) mm in 722 patients, with an average peeling times of (11.62±4.28) and average blood loss of (6.22±2.08) mL. The average diameter of removed tissue was 2.0-3.5 mm with an average length of (13.69±5.06) mm. An average operation time for single mass was (7.85±2.91) min. Complications were mainly pain (n=32) and bruising (n=26) in 33 patients (4.57%). A total of 1 367 breast lumps were found in 722 patients, in which there were 683 fibroadenoma (49.96%). Thirteen patients (1.59%) were found mass residue during follow-up. The pro⁃ portion of mass residue was increased with the increased number of mass, and was higher in mass diameter above 2 cm than in diameter less 2 cm, and also higher in tumor without clear boundary group than that with clear boundary group, and higher in patients with hematoma and bruising than that without hematoma and bruising. Mass diameter > 2 cm, no clear boundary, multiple tumors and hematoma formation were independent risk factors of mass residue. Conclusion The mammotome minimally invasive operation is a safe and potent therapeutic management for benign breast mass. Comprehensive evaluation of the tumor size, tumor boundary, the number of mass before operation can reduce the risk of mass residue.

Key words: breast diseases, surgical procedures, minimally invasive, risk factor, mammotome biopsy system