Fig. 3

Gross appearances of the lung and thoracic viscera of MWNT-7-treated rats. A Whitish and yellow nodule (yellow arrow, adenoma) on the surface of the lung of a rat in the low-dose group. The rat was sacrificed at week 104. B White nodule (yellow arrow, adenoma) on the surface of the lung of a rat in the high-dose group. The rat was sacrificed due to the progression of a neck tumor (hemangiosarcoma) at week 89. C Appearance of the mediastinum of a rat that had no proliferative lesions. Retrocardiac pleural folds (RPFs) extend from the pericardium to the diaphragm, and enwrap the accessory lobe. D, E, F Malignant pleural mesotheliomas found in the high-dose group (sacrificed at weeks 81, 93, and 81). Multiple small or large nodules of the mesothelioma are seen on the surface of the serosa of the mediastinum (green arrowheads). F Rat with a cardiac tamponade evidenced by the enlarged pericardium containing bloody fluid