Objective To evaluate the value of ultrasound-guided mammotome in the diagnosis and therapy of breast tumor.Methods From May 2006 to February 2009,a total of 205 cases diagnosed with breast tumor by physical examination or ultrasonography underwent ultrasound-guided mammotome in our department.In the patients,142 cases had single tumor and 63 cases showed multiple tumors.Among the 205 cases,impalpable lesions were detected by ultrasonography in 58 patients.Mammotome biopsy system with 11 G/8 G needles were used in the operation.After the surgery,pathological examination was carried out,and short-and medium-term follow-up results of the patients were analyzed.Results In the 205 cases,totally 356 tumors were detected.The size of the tumors ranged from 0.3 to 3.5 cm in diameter.The operation time of the patients was 10.2 min in average(1-50 min).After the surgery,22 patients showed bruise in the surgical area,and 19 patients developed hematoma(three of them received puncture of the hematoma).Post-operative pathological examination showed fibroadenoma in 98 cases,breast hyperplasia in 246 cases(154 of them were complicated with fibroadenoma),7 had intraductal papilloma,4 were diagnosed with breast cyst,and 1 showed tubular adenoma.Follow-up was achieved in 132 patients for 2 to 36 months,during the period,residual tumor was detected in 4 patients(3.0%).All the patients were satisfied with the cosmetic results of the surgery.Conclusions Ultrasound-guided mammotome is a minimally invasive procedure that can safely and reliably diagnose and remove breast tumor,particularly multiple tumors and impalpable lesions.The cosmetic results of the operation are satisfying.