Synoviocyteproliferation	0 normal 1 slight 2 moderate 3 severe	One layer Up to two cells deep Up to four cells deep Up to more than four cells deep
Hypertrophy	0 normal 1 slight 2 moderate 3 severe	Squamous Cuboidal Cylindrical Cylindrical withcytoplasmic protrusions
Inflammatory infiltrate	0 absent 1 slight 2 moderate 3 severe	Few cells Some foci of cells Diffuse infiltration
Fibrinous exudate	0 absent 1 slight 2 moderate 3 severe	Slight amount,focal Multifocal deposits of fibrin Diffuse deposits of fibrine
Lymphoplasmacytic infiltrate	0 absent 1 slight 2 moderate 3 severe	Single/few cells Some cells, mainly arrounvessels Many cells,diffuse infiltration
Lymphoplasmacytic aggregates	0 Absent 1 single 2 many	1 >1
Synovial stroma villous hyperplasia	0 absent 1 slight 2 moderate 3 severe	No villi/smooth waves Some small villi Multifocal villous hyperplasia Diffusevillous hyperplasia
Proliferation of fibroblasts/fibrocytes	0 absent 1 slight 2 moderate 3 severe	Normal cellularity density Mild proliferation Moderate proliferation Extensive proliferation
Proliferation of blood vessels	0 normal 1 slight 2 moderate 3 severe	Mild proliferation Moderate proliferation Extensive proliferation
Cartilage/bone_detritus	0 absent 1 few 2 many	1–3 >3
Hemosiderosis	0 absent 2 few cells 3 many cells	1–3 >3