[Surgically treated desmoid tumor of the chest wall which located at the previous thoracotomy site].

Desmoid tumor is a soft-tissue tumor of unknown cause. Since recurrence sometimes occurs even with complete resection, careful consideration of which portions to resect and close postoperative followup are recommended. Seventeen months after undergoing a right upper lobectomy for primary lung adenocarcinoma, a 65-year-old female patient experienced pleural tumor which located at the previous thoracotomy site, as revealed by chest X-ray and computed tomography (CT). While needle aspiration biopsy revealed no malignancy, recurrence of the cancer could not be ruled out clinically. The tumor was resected with chest wall and lung and the histopathological diagnosis was desmoid tumor. This case demonstrates the importance of conducting differential diagnosis with recurrence or desmoid tumor after operation to treat lung cancer. Five years after resection of the desmoid tumor, no recurrence is observed.