NKX2-1 and adenocarcinoma: Classic adenocarcinoma (ADC) markers were used, including cytokeratin 7 (CK7), thyroid transcription factor 1 (TTF-1), and napsin A. The results of H&E staining and IHC indicated that the LCOs retained the histopathological characteristics of the original tumor tissue or malignant pleural effusion.