Malignant serosal tumors in the lung (A) and the diaphragm (B) in mice exposed to MC followed by MWCNT. A. The photomicrograph shows a pulmonary vein in the right cardiac lung lobe that contained variably-sized polygonal to spindloid cells similar to those on the diaphragm (Figure 8B). The arrow indicates a metastasis of the malignant serosal tumor (20×). The magnification bar is 50 microns. B. The skeletal muscle of the diaphragm in the photomicrograph is infiltrated by a nodular mass composed of variably-sized polygonal to spindloid cells (malignant serosal tumors). (20×). The magnification bar is 50 microns.