 Experimental group: percutaneous RFA previous to conventional lumpectomy. Control group: conventional surgery with lumpectomy. The number of positive margins in both groups, and the need of extending margin resection will be assessed intraoperatively. Inclusion criteria: women 40 years, infiltrating ductal breast carcinoma by biopsy. The tumor must be unique, visible by ultrasound, smaller than 2cm and located 1 cm from the chest wall and the skin. Patients will be followed up for a period of two years to assess cosmetic result, short -term and long -term complications and recurrences. 