Table 1.

Structural components of PA according to Willis [6]

1. Nearly normal-looking salivary tissue

2. Atypical glandular tissue

3. Atypical glandular tissue with marginal epithelial sprouting

4. Solid epithelial formations

5. Epithelial formations with cystic spaces

6. Cornifying stratified epithelial structures

7. Epithelial filaments and networks in a mucinous matrix

8. The so-called “cartilage-like tissue”