Table 1. Definitions of Pathological Changes of Chronic Cholecystitis.

Pathological Changes of Chronic Cholecystitis	Definition
Inflammatory mononuclear infiltrate
Mild	Diffuse, ≤10 inflammatory cells per HPF in any layer
Moderate	Diffuse, between 11 to 30 cells per HPF
Severe	Diffuse, more than 31 cells per HPF or follicular
Degree of fibrosis
Mild	Uneven collagen deposition in ≤20% of material
Moderate	Uneven collagen deposition in 21% to 70% of material
Severe	Uneven collagen or lamellar fibroplasia in ≥71% of material
Thickness of the muscular layer
Mild	Less than one third of the whole thickness
Moderate	One third to two thirds of the wall
Severe	More than two thirds of the wall thickness
Addipose tissue deposition
Mild	Up to 10% of the material
Moderate	11% to 60% of the material
Severe	More than 60% of the material
Degree of hyperplasia
Diffuse	≥70% of the whole sections
Focal	<70% of the whole sections
Degree of dysplasia
Low-grade	Resemble tubular adenomas of the colon without intestinal metaplasia
High-grade	Markedly pleomorphic nuclei and/or prominent nucleoli
Metaplasia
Pyloric type	Structures similar to the pyloric glands in the lamina propria
Intestinal type	Goblet cells and enterocitlike cells
Gastric surface type	Epithelial cells of gallbladder mucosa replaced by tall columnar cells with abundant mucin and basallylocated nuclei

HPF: high power field.