Incidence of mast cells in oral inflammatory lesions: A pilot study

Mast Cells: Key Players in the Shadow in Oral Inflammation and in Squamous Cell Carcinoma of the Oral Cavity

Although mast cells (MCs) have been discovered over 130 years ago, their function was almost exclusively linked to allergic affections. At the time being, it is well known that MCs possess a great variety of roles, in both physiologic and pathologic conditions. In the oral tissues, MCs release different proinflammatory cytokines, tumor necrosis factor alpha (TNF-α), that promote leukocyte infiltration in various inflammatory states of the oral cavity. These cells play a key role in the inflammatory process and, as a consequence, their number changes in different pathologic conditions of the oral cavity, like gingivitis, periodontitis, and so on. MCs also represent a rich source of proteases, especially of mast cell tryptase and chymase, which directly degrade the extracellular matrix through their proteolytic activity and thus indirectly stimulate angiogenesis and facilitate invasion and metastasis. It may be stated that mast cells could have an impact on primary tumor development, progression, and metastases in oral squamous cell carcinoma. By understanding the role of mast cells in the pathogenesis of different inflammatory and tumor diseases of the oral cavity, these cells may become therapeutic targets that could possibly improve the prognosis and survival of these patients.

A quantitative analysis of mast cells in inflammatory periapical and gingival lesions

AIM

The aim of the study was to quantify the presence of mast cells in various inflammatory lesions like periapical granuloma, periapical cyst, inflammatory gingival hyperplasia and pyogenic granuloma. Mast cell degranulation and association with lymphocytes were also recorded in an attempt to understand the role of mast cells in the pathogenesis of these inflammatory lesions.

MATERIALS AND METHODS

The quantification of mast cells was done on toluidine blue stained sections of all the four groups of lesions, using the image analyzer software, Image-Pro-Express (Media Cybernetics, USA).

RESULTS

An increased number of mast cells in various inflammatory lesions with a significant difference between the four groups were noted. Mast cell number tended to be greater in the lesions present in the anterior region of the mouth than in the posterior region of the oral cavity. The mean mast cell number decreased with the increasing age which was directly correlated with the age of the patients. Mast cell site, distribution, degranulation and its association with fibroblasts, lymphocytes and blood vessels were noted.

CONCLUSION

The location of mast cells in different areas, their association with lymphocytes, fibroblasts, endothelial cells, and the phenomenon of degranulation helps to appreciate the release of various mediators and multiple interactions among these cells, leading to increased vascular permeability, angiogenic response, collagen synthesis, regulation of inflammation, bone resorption, and extracellular matrix destruction, thus contributing to the pathogenesis of these inflammatory lesions.

Incidence of mast cells in oral squamous cell carcinoma: a short study

Mast cells are regarded as complex and multifunctional cells, playing a significant role in immunopathology and a substantial role in tumor angiogenesis. Angiogenesis is a complex process that is tightly regulated by various growth factors in which mast cells act directly by releasing angiogenic factors and henceforth promoting tumor growth and metastasis. The aim of this study is to evaluate the number of mast cells in tissue sections of oral squamous cell carcinoma (OSCC) in comparison with normal mucosa. A total of 40 cases (20 OSCC and 20 normal mucosa) were stained with 1% toluidine blue and the quantitative analysis was done by using light microscope under 400x magnification. A significant increase in the mast cell count was observed in the sections of OSCC when compared to normal mucosa suggesting their contributing role in tumor growth and progression.