Demonstration of secretory component, IgA, and IgM by the peroxidase-antiperoxidase technique in inverted papillomas of the nasal cavities.

Fifteen inverted papillomas were examined by the peroxidase-antiperoxidase method for their ability to synthesize secretory component (SC) and to take up IgA and IgM. In each case, SC and IgA could be localized to the apical cytoplasm of some tumor cells. In addition, secretory component, IgA, and IgM were observed as the main constituents of hyaline globules lying in the intracytoplasmic lumina of one columnar cell variant of inverted papilloma, suggesting an intact transepithelial transport mechanism of polymeric immunoglobulins. Goblet cells, found only in the transitional cell variant of inverted papilloma, did not react with anti-SC, anti-IgA, or anti-IgM. Since SC can be utilized as a marker to differentiate columnar cells from goblet cells, transitional cell papillomas may originate from undifferentiated reserve cells, which retain their capacity to differentiate into both columnar cells and goblet cells. In contrast, in columnar cell papillomas only differentiated columnar cells are integrated into the neoplastic process.