Background: An ambiguity persists regarding variation in clinical aggressiveness of different oral lesions, among which are the giant cell granulomas. Different types of giant cell granulomas can develop in the jaws, including peripheral giant cell granuloma, and central giant cell granuloma, whether aggressive or non-aggressive, each of which show different clinical behavior. Although they show great resemblance histologically on the cellular level, still they may show variation in other histological components as those regarding collagen fibers present. This raises the question about any possible relationship between the clinical behavior and histological components of these lesions.
Aim of the Work: This study aimed to investigate and explore the possible correlation between immunohistochemical detection of tumor associated macrophages (TAMs) using CD163 and the density, packing and type of collagen in giant cell granulomas of the jaws and the role of this correlation in the variation of clinical aggressiveness of these lesions.
Methods: We measured the immunohistochemical expression of CD163 and quality of collagen fibers, using picrosirius red stain in normal oral mucosa, peripheral giant cell granuloma, non-aggressive and aggressive central giant cell granulomas (10 samples each).
Results: Our results indicate that the expression of CD163 showed a statistically significant increase in aggressive central giant granuloma as compared to the non-aggressive samples. Moreover, picrosirius staining revealed that samples from aggressive lesions showed predominant green-yellow birefringence indicating higher expression of collagen type III in these lesions.
Conclusion: These findings suggested a possible influencing role of TAMs and increased deposition of collagen type III in the progression and aggressive behavior of giant cell granulomas of the jaws.