TABLE 1.

Pathological grading criteria of abdominal lesions

Diagnosis		Gross and microscopic findings	Total Consecutive Grade
No change		No or minimal change.	0
Inflammation	Weak	Minimal infiltration of inflammatory cells with frequent finding of the deposition of MWCNT‐laden macrophages at the lymphatic infiltration of the peritoneum. No reactive change on mesothelial cells.	1
	Intermediate	Frequent findings of edematously thickened mesothelium with fibrosis. Infiltrations of eosinophil, monocyte, macrophage, and mast cell.	2
	Strong	Marked infiltration of monocytes and reactively proliferated mesothelial cells in the surface of the mesothelium.	3
Hyperplasia		Protrusion of several layers of enlarged mesothelial cells accompanied with rich connective tissue‐like cells. Occasional appearance of atypical mesothelial cell bulging or mitotic figures.	4
Mesothelioma	Grade‐1	Fine nodules or protrusion on the surface of the serosa, grossly recognizable but not so marked. No invasion or metastasis.	5
	Grade‐2	Small nodules larger than 1 mm in diameter throughout the coelom. Thickness of the plaque‐like tumor mass less than 3 mm on the diaphragm.	6
	Grade‐3	Wide distribution of tumor nodules in the coelom including the scrotum. A few large nodules more than 10 mm. Thickness of the plaque‐like tumor mass more than 3 mm on the diaphragm.	7
	Grade‐4	Large tumors (nodule/mass and thick plaques) occupied the coelom. A few huge nodules at least more than 10 mm with some being 20‐30 mm. More than 10 of nodules with large (more than 10 mm) or middle (5‐10 mm) sizes, or thick plaque more than 3 mm covering throughout the serosa. Tumor invasion surrounding tissues including digestive tract wall, the parenchyma of liver, kidney, spleen, and the coelomic walls.	8