KRT7 and adenocarcinoma: Histopathological examination of the hilar lesion revealed a well-differentiated adenocarcinoma, immunohistochemically proven to be metastasis from colon cancer based on negative staining for Cytokeratin 7 and positive staining for Cytokeratin 20 (Figure 3A,B,C); it was also shown that the subpleural lesions were adenocarcinoma, proven to be metastases from prostate cancer based on positive staining for PSA (Figure 3D,E).