Table 1 Criteria for determining the presence of the histological characteristics of the adventitial layer.

Laminated layer disorganization

Either whole laminated segments inside the adventitial layer or host cell infiltration between the laminated layer sheets

At least one in the entire sample

Necrosis between the laminated and adventitial layer

Presence of an eosinophilic zone devoid of cells without a fibrous structure

Across one low-power magnification field (approximately 5 mm)

Calcifications

Presence of strong haematoxylin staining without cells and with crystal structures

At least one in the entire sample

Host cells in the germinal layer

As previously described [42]

At least one in the entire sample

Giant multinucleated cells

Cells with 5 or more nuclei near the laminated layer

At least one per high-power magnification field (1 mm)

Palisading macrophages

The presence of foamy macrophages with cytoplasmic projections in contact with the laminated layer

Across one low-power magnification field

Lymphoid follicles

Circular structures with lymphocytes near the laminated layer

At least one per low-power magnification field

Eosinophils

Cells with eosinophilic cytoplasm near the laminated layer

At least ten or more eosinophil nuclei per high-power magnification field