CD274 and non-small cell lung carcinoma: Given the aforementioned clinical evidence, including multiple radiological examinations, the pathologically confirmed pleomorphic carcinoma from NSCLC with high PD-L1 expression, and the left lung bullae resection history 2 years ago, through the MDT consultation, the final diagnosis was confirmed as mediastinal lymph node metastatic SC (pleomorphic carcinoma) with probably pulmonary origin but unclear primary lesion, stage III [cTxN2M0, American Joint Committee on Cancer (AJCC) 8th].