[A case of pulmonary metastasis from carcinosarcoma of uterus with subcutaneous implantation of tumor cells along the needle tract after percutaneous needle biopsy of lung].

A 68-year-old female who had undergone total hysterectomy for carcinosarcoma five months previously was noted to have a solitary nodular shadow in the right lung on chest X-ray. Percutaneous needle biopsy of the lung was performed via the right anterior chest wall, and the histologic findings showed metastasis from carcinosarcoma of uterus. Two months after needle biopsy, a chest wall mass appeared of the site of puncture of the lung needle biopsy. The mass was resected to relieve the chest wall pain and the specimen showed carcinosarcoma of uterus histologically. We consider that tumor cells were implanted to the chest wall along the needle tract after percutaneous needle biopsy of the lung. The postoperative chest computed tomogram showed the route of tumor implantation from the metastasis of right lung into the right chest wall. Dissemination and chest wall implantation of malignant cells after percutaneous lung needle biopsy have been rarely reported. However there are no reports of tumor implantation of sarcoma. The possibility of implantation of tumor cells along the needle tract after percutaneous lung needle biopsy should be carefully considered in cases of carcinosarcoma.