Metachronous bilateral breast cancer presenting at the site of an implanted pacemaker: report of a case

A 72-years-old woman presented with breast cancer at the site of pacemaker implantation. She had undergone left pectoral muscle-preserving mastectomy and axillary lymph node dissection for left breast cancer at the age of 56 years. A mass measuring 1.0 cm in diameter was palpable in the C region of the right breast. Mammography, ultrasonographic examination, and core-needle biopsy led to a diagnosis of left breast scirrhous carcinoma. She had a history of Mobitz type Ⅱatrioventricular block, and undergone implantation of a pacemaker via the subclavian route 1 year ago. The cancer was not adjacent to the pacemaker, but was at a distance of 7.5cm. Thus, we performed mastectomy and sentinel lymph node biopsy, without pacemaker reimplantation or generator and lead injury, using indigo carmine marking and an ultrasonic scalpel. Only 3 such cases have been reported in the Japanese literature in the past 20 years. We report the present case with a review of the literature and discuss the operative procedure and adjuvant therapy, including radiotherapy.