The investigators will perform this study to prospectively compare the clinical outcome after percutaneous microwave ablation(MWA) and cryoablation of benign and malignant breast lesion under ultrasound (US) guidance.

A total of more than 200 patients diagnosed with benign breast lesions and 50 patients with malignant breast lesions in two centers of China will be recruited in this study and underwent US-guided percutaneous MWA and cryoablation treatment. Information for each patient includes demographics; longest diameters of tumors; tumor numbers; tumor pathological type; location of tumor according to whether adjacent to skin, pectoralis, areola and papilla. Ablation variables including session, puncture, time, and power; complete ablation, complications; reduction in volume, palpability, pain and cosmetic satisfying outcomes,recurrence,survival will be compared and analyzed.

Inclusion Criteria:

• (a) the breast tumor obtained the pathological diagnosis by using core-needle biopsy; (b) for the benign lesion, continually increasing during a half year followup,with the symptoms of local pain, discomfortable or compression considered probably relating to the mass of breast; the patient with evidently psychological pressure due to the occurrence of the BBL despite clearly benignancy on imaging; (c) for the malignant lesion, with the tumor size smaller than 2cm and without other metastasis.

Exclusion Criteria:

• (a) the patients who were pregnant or breast-feeding; (b) the patients with evidence of coagulopathy or acute or severe pulmonary insufficiency or heart dysfunction; (c) the patients during menstrual period; (d) the patients referring to other therapies including surgical excision and vacuum-assisted biopsy.