Simultaneous Chest Wall Reconstruction after Sternectomy and Modified Radical Mastectomy in Locally Advanced Breast Cancer with Solitary Sternal Metastasis
A 28-year-old woman was admitted for left breast cancer with nipple retraction, palpable axillary lymph nodes, and dull pain in the upper-mid chest. Mammography revealed ill-defined hyperdense mass involving left whole breast with nipple retraction and diffuse skin and trabecular thickening with enlarged lymph nodes in left axilla. Breast ultrasonography showed an ill-defined irregular mass involving the entire left breast with diffuse skin thickening and nipple retraction and multiple malignant looking axillary lymph nodes were apparent. An image-guided core biopsy showed invasive ductal carcinoma and image-guided fine needle aspiration revealed metastatic ductal carcinoma in the axillary lymph node. The tumor was positive for the estrogen receptor and progesterone receptor but negative for human epidermal growth factor receptor type 2 (HER2). Initial breast magnetic resonance imaging (MRI) showed an enhanced nodule in the sternal body, caused by metastasis (). But, initial 18F-fluoro-2-D-glucose positron emission tomography with computed tomography (18FDG PET/CT) and bone scintigraphy showed negative findings in the sternum, and only the left highest mediastinal area and left supraclavicular lymph nodes metastasis appeared on the 18FDG-PET/CT (). The patient underwent palliative chemotherapy consisting of 50 mg/m2 body surface area (BSA) doxorubicin and 75 mg/m2 BSA docetaxel, every 3 weeks. Efficacy was assessed as a partial response on breast MRI after four cycles. The breast MRI showed an interval decrease in the entire left breast mass, left multiple metastatic axillary lymph nodes and metastatic nodule at the sternal body (). She elected to have surgery after 4 months from her initial presentation. A left modified radical mastectomy with level III axillary lymph nodes dissection and partial sternectomy with chest wall reconstruction were performed (). After longitudinal division of the pectoralis major muscle, periosteal elevation around the metastatic lesion including the third and fourth ribs was performed. A frozen section of the sternal mass was revealed metastatic ductal carcinoma. A subtotal sternectomy including the lower half of the sternal body was performed with an osteotome and oscillating saw. The resection field was over the left third and fourth costal cartilage margins of the intercostal muscles and the enlarged parasternal lymph nodes but excluded the unaffected lateral part of the pectoralis major muscles. After we identified that the frozen section result for resection margin was clear, we immediately repaired the large anterior chest-wall defect with a 2 mm thick polytetrafluoroethylene Gore-Tex soft tissue patch (W. L. Gore & Associates, Flagstaff, USA), which was sutured to the ribs, rectus abdominis muscles, and the remaining part of the sternum. The soft tissue was covered smoothly with layer by layer sutures of the pectoralis major muscles and subcutaneous tissue once the Gore-Tex patch was sutured in place. Microscopic examination of the breast and bone marrow sections revealed clusters of infiltrating ductal carcinoma (). She was extubated immediately after surgery with no postoperative complications. The patient did not have any problems with daily activities or chest movement. She was discharged from the hospital 10 days after the operation. Pathology revealed a 10.2×9.5×3.2 cm sized invasive ductal carcinoma with no involvement of the skin or nipple, but 12 axillary lymph nodes were involved along with the sternal metastasis. She received two additional cycles of chemotherapy followed by radiotherapy. We checked 18FDG-PET/CT and bone scintigraphy to confirm the surgical site and the sternum before and after radiotherapy (, ). The patient underwent the endocrine and bisphosphonate therapy and was well 36 months after the diagnosis. She exhibited no evidence of recurrent disease on the last imaging study, 18FDG-PET/CT, bone scintigraphy, or breast MRI (). She is being followed up carefully every 4 weeks.