Mast cells in periapical lesions: potential role in their pathogenesis.

Objective: The aim of this study was to qualitatively and semi-quantitatively analyze mast cells in periapical lesions.
Materials and Methods: Biopsy specimens of 96 periapical lesions were stained with hematoxylin-eosin, histochemical Giemsa and immunohistochemical CD 117 (C kit) antibody. Mast cell count below 100 mast cells on 1000 fields of high power magnification was noted as 'negative', 101-400 as 'mild', 401-800 cells as 'moderate', and over 800 cells as 'severe'.
Results: Mast cells are found in 68 (70.8%) lesions. The presence of mast cells was greater in cysts than in granulomas (P < 0.0028). There was no difference in semi-quantitative expression of CD 117 in granulomas and cysts (P > 0.05). Mast cells were placed in both: inflammatory infiltrate and in fibroblastic areas of periapical lesions, and their presence was most frequently mild to moderate.
Conclusions: The findings of present study could suggest a role of mast cells in regulation of cellular immune mechanisms in periapical lesions, balancing between alterative and reparatory processes in inflamed periapical tissue.