Pembrolizumab が著効した歯肉転移・胸膜播種を伴う肺多形癌

We present a case of a 67-year-old woman who was pointed out a 1.8 cm nodule in the left inferior lobe by chest computed tomography（ CT）. Lung cancer was suspected and the surgery was scheduled. Before surgery, perioperative oral care was performed and gingival tumor doubtful of metastatic lesion was found. After the resection of the lung tumors, the diagnosis of pleomorphic carcinoma with pleural dissemination and gingival metastasis was established. Because high programmed cell death 1 ligand 1 （PD-L1） expression was demonstrated in the specimen of the lung, she was treated with pembrolizumab as an initial treatment, which led to a complete response. Twenty months after initiating of pembrolizumab therapy, she is doing well without recurrence of pleomorphic carcinoma.