DISTRIBUTION OF MAST-CELLS IN INVERTED PAPILLOMA AND SQUAMOUS-CELL CARCINOMA OF THE NOSE

An increased number of mast cells is found in the epithelial layer of the nasal mucosa of allergic subjects. However the mechanism of accumulation of the intraepithelial mast cells has not yet been clarified We have previously shown that the increase of intraepithelial mast cells is related to the proliferation of nasal epithelial cells in vivo, and inverted papilloma and squamous cell carcinoma of the nose seem to be in vivo proliferative states of nasal epithelium. To clarify the mechanism of the accumulation of intraepithelial mast cells, we studied the relationship between nasal tumors of epithelial cell origin and the accumulation of mast cells. Accumulation of mast cells was observed in the nasal inverted papilloma, especially within 50 mu m from the basement membrane at the tumor site, which might be the site of maximum proliferation of tumor cells as well as secretion of cytokines. The majority of mast cells accumulated were formalin sensitive mast cells (mainly MMCs). On the other hand, in the squamous cell carcinoma of the maxillary sinus, fewer mast cells were found. Results of this study suggest that the accumulation of intraepithelial mast cells is associated with the proliferation of nasal epithelial cells.