Intra-tumoral metastatic double primary carcinoma: Synchronous metastatic tumor in lung from breast and thyroid carcinoma

Cases of phenotypic heterogeneity of cells within tumors have recently been reported. Here, we report on a patient with characteristic intra-tumor double primary metastases in the lung. This patient was a 40-year-old Korean woman who had been diagnosed with breast cancer (T1N0M0, estrogen receptor/progesterone receptor/HER2 +/+/+) and papillary thyroid cancer three years prior and underwent a complete surgical resection followed by appropriate adjuvant treatment with radiation, hormone, and radioactive iodine. She was recently admitted for newly developed pulmonary nodules. Metastasectomy through video-assisted thoracoscopic surgery revealed recurrent double primary cancer with two different components (metastatic ductal carcinomas from the breast and metastatic papillary carcinomas from the thyroid gland) in each pulmonary nodule in the right upper lobe and right middle lobe. To the best of our knowledge, this is the first report of simultaneous recurrent double metastasis in one organ from different primary origins.