Hilar nodule and tumor cells. (A) A hilar nodule showing well-differentiated adenocarcinoma (hematoxlyin and eosin [H & E], ×75). (B) Immunohistochemically, tumor cells in the hilum were negative for Cytokeratin 7. (CK7, ×150). (C) Tumor cells in the hilum were positive for Cytokeratin 20 and consistent with metastasis from colon cancer. (CK20, ×150). (D) Subpleural nodule also showing adenocarcinoma. (H & E, ×150). (E) Tumor cells in the subpleural nodule were positive for prostate-specific antigen and confirmed as metastasis from prostate cancer (PSA, ×150).