2023 Volume 84 Issue 9 Pages 1384-1390
A 70-year-old woman with a pacemaker (PM) implanted in her left anterior chest four years previously noticed a mass in her left axilla and visited our hospital. A growth with a diameter of 6 cm, centered in the E region of the left breast, was detected, and enlarged lymph nodes were identified in the left axilla. A biopsy revealed an invasive ductal carcinoma. However, lymph node metastasis was also discovered in the left supraclavicular region, leading to a locally advanced breast cancer diagnosis. Preoperative chemotherapy was performed so that cancer in her left breast, including the left supraclavicular lymph node, shrank and was rendered operable. Postoperative radiotherapy was indicated, and a leadless PM was implanted preoperatively. A calcified lesion was also found in her right breast, and the biopsy diagnosis confirmed noninvasive ductal carcinoma. Bilateral mastectomy, left axillary lymph node dissection, and right sentinel lymph node biopsy were performed. The patient underwent a total left mastectomy followed by radiotherapy (50 Gy/25 Fr) as scheduled, without recurrence, for four years after surgery. With the aging of the population, the number of PM implantation cases is increasing. Careful diagnosis and treatment are required when breast cancer occurs at the site of PM implantation.