Importance of mast cells in human periapical inflammatory lesions.

The role of mast cells (MCs) in periapical inflammatory lesions is not well understood. The objective of this work was to quantify MC numbers in human periapical lesions with the aim to clarify their role in the pathogenesis of these lesions. We analyzed the slides of 64 human periapical inflammatory lesions stained with pH 8.0 toluidine blue technique, quantified the number of MCs, and evaluated any correlation with age, gender, size, and location. The results of this study suggest that MCs were more numerous in females (p < 0.01); MC numbers were higher in biopsies from granulomas with proliferating epithelium and lower in biopsies from chronic apical abscesses; MC counts did not correlate with patients' age or size. MCs were observed more commonly in areas containing inflammatory infiltrate and degranulation was a frequent finding in these zones. Our results suggest that MCs play an active role in the pathogenesis of the periapical inflammatory lesions. The potential role of MCs related with the initiation, development, and persistence of the periapical inflammatory process are discussed.