A case of port-site implantation in the breast after endoscopic thyroid surgery

Abstract

The patient was a 42-year-old woman who noticed a lump in her breast and was examined by a local physician, who referred her to our hospital. Mammography showed a category 4, polygonal mass, 13 mm in size, with unclear margins at its boundaries in the upper inner quadrant of the left breast, and ultrasonography revealed a polygonally-shaped isoechoic lesion with clear margins and no interruption of the anterior margin, diagnosed as category 4. Magnetic resonance imaging (MRI) showed that the mass was densely stained in the early contrast period. Because the mass was class III according to fine-needle aspiration cytology and was diagnosed as atypical ductal adenoma by Mammotome biopsy, partial mastectomy was performed. Tumor tissue was positive on thyroglobulin and TTF-1 staining, indicating that it was derived from the thyroid gland. When the patient was asked about her history of thyroid disease, she mentioned that she had undergone endoscopic thyroidectomy for thyroid follicular adenoma at another hospital seven years earlier. Based on the location of the mass, the patient was diagnosed with port-site implantation occurring after endoscopic thyroidectomy. This case demonstrates the possibility that port-site implantation may occur even in cases diagnosed as benign thyroid adenoma, and it provides a useful reference for future endoscopic surgery.