Quantification of inflammatory, angiogenic, and fibrous components of reactive oral lesions with an insight into the pathogenesis

BACKGROUND: Reactive oral lesions pose diagnostic difficulties as they mimic each other clinically. A definitive diagnosis is made based on the histopathological presentation of this group of lesion. Stromal microenvironment is the key to the sequence of the stages of these lesions. Stringent quantification of each component of the stroma is important to understand the pathogenesis. The aim is to evaluate inflammation, angiogenesis, and fibrosis in the reactive group of lesions through quantitative analysis. MATERIALS AND METHODS: Blocks of irritation fibroma, inflammatory fibrous hyperplasia, pyogenic granuloma, and normal mucosa were retrieved from the archives and Hematoxylin and Eosin (H&E) and Masson Trichrome staining were done. The severity of inflammation, epithelial thickness, collagen proportionate area, integrated density of collagen, Mean Vascular Area (MVA), Mean Vascular Perimeter (MVP), and Mean blood vessel percentage area (MBVPA) were analysed quantitatively using Image J software version 1.8. The pattern of rete ridges at the epithelium-connective tissue interface was analysed qualitatively. RESULTS: Inflammatory fibrous hyperplasia presented with severe inflammation (60%). Mean Vascular Percentage Area (MVPA) and Mean Vascular Perimeter (MVP) were increased in pyogenic granuloma. The mean collagen proportionate area and the integrated density of collagen were found to be more in irritation fibroma (64.47%, 2519638.01 ± 810471.58 μm(2)). The epithelial thickness was highest in inflammatory fibrous hyperplasia (62.71 ± 18.86 μm). CONCLUSION: Reactive oral lesions are histologically distinct, yet they exhibit considerable overlap depending on the stage of the lesion. A morphometric quantitative exploration of the individual pathogenic components may aid in specific diagnosis.