Microscopic findings of primary and metastatic pleural tumors. The lesion comprised tumor cells with abundant clear cytoplasm and small round nuclei with atypia in both primary tumor and metastatic tumor at the pleura (hematoxylin and eosin stain). (A) Primary lesion of the kidney (low magnification). (B) Primary lesion of the kidney (high magnification). (C) Resected tumor with rib and lung. (D) Histological specimen by magnifying glass. (E) Metastatic pleural tumor (low magnification). (F) Metastatic pleural tumor (high magnification).