[A case of cStage III B non-squamous non-small-cell lung cancer completely resected after downstaging with chemotherapy].

A 64-year-old man was diagnosed with a gastric ulcer, and a tumor shadow was observed in the right lower lung field on a chest radiograph. Chest computed tomography (CT) revealed the tumor shadow to be 33 × 25 mm in the right lower lobe; it also revealed a 7-mm nodule in the right S3, and lymph node swelling in the upper and lower mediastinum. Positron emission tomography (PET)-CT revealed an SUVmax of 12.8, 1.2, 7.6, and 10.0 for the right lower lobe tumor, right S3 nodule, and the No. 4 and No. 7 lymph nodes, respectively. The right lower lobe tumor was diagnosed as an adenocarcinoma via transbronchiall ung biopsy. The patient was diagnosed with cT4N2M0, cStage III B cancer. Four courses of carboplatin, pemetrexed, and bevacizumab were administered. After the fourth course, chest CT revealed that the right lower lobe tumor and the right S3 nodule significantly reduced to 14 × 7 mm and 5mm respectively, and the mediastinal lymph node swelling was nearly eliminated. Subsequent PET-CT examination revealed an SUVmax of 1.3 and 0.8 in the right lower lobe tumor and right S3 nodule, respectively. The patient was diagnosed with ycT4N0M0, ycStage III A cancer, and he underwent right lower lobe resection, right S3 partial resection, and lymph node. Postoperative pathological analysis was used to make a diagnosis of mixed type adenocarcinoma for the right lower lobe tumor, and a diagnosis of papillary adenocarcinoma for the right S3 nodule. Both tumors were diagnosed as primary lung cancers. There were no metastatic cancer cells in the dissected lymph nodes.