RHINOSPORIDIOSIS - IMMUNOHISTOCHEMICAL AND ELECTRON-MICROSCOPIC STUDIES

Sixteen biopsies of rhinosporidiosis (15 nasal and one conjunctival) f rom 16 Southern Indian male immigrant workers showed mucosal lymphopla smacellular infiltrates together with transepithelial elimination of n odular bodies and destruction of some late stage nodular bodies in his tiocytic granulomata with central neutrophilic microabscesses. Early n odular bodies were immunohistochemically positive for alpha(1)-AT, alp ha(1)-ACT, CEA, S100, fibronectin, amyloid-p-component, IgG, IgA, C-1q and C-3. Electron microscopy showed organized concentric lamellated b odies in early nodular bodies and not in end-stage nodular bodies whic h contained mostly amorphous electron dense materials. Structures form erly regarded as 'sporangia' and 'spores' are believed to be lysosomal bodies loaded with indigestible residues to be cleared via transepith elial elimination or segregated/destroyed by secondary immune/granulom atous responses.