Abstract: Objective: To investigate the features of the histopathologyand serologyof syphilis in oropharynx and the immunohistochemical staining characteristics of treponema pallidum. Methods: Six syphilis patients in oropharynx were analysed by means of epipharyngoscope, histopathology, immuno-histochemistry and serology. Furthermore, the features of clinical presentation, histology, and immunohistochemistry of those patients were generally analysed combined with the related literatures.Results: The average age of ten rolled patients was 28.3 years. Erythema, leukoplakia, and erosion of mucous membrane were the main presentation, and the protruding plaque was also noted. The serologic examination showed RPR>1∶8(+), TPPA(+). Histologic examination demonstrated the infiltration of massive plasma cells, histocytes, and lymphocytes in the lamina propria of mucous membrane underlying the squamous epithelium layer, constituting the granulomatous pattern. The vasculitis was also present. The scattered Micropironema pallidum was detected by immunostaining. Conclusion: The features of the histopathology and serology of syphilis in oropharynx mucosa had its specific characteristics, and the primary lesions of erythema, leukoplakia and erosion or ulcers in oropharynx should be attracted attention by the otolaryngology doctors, and the potential diagnosis of syphilis should be thought and confirmed by pathological and pathogenic examination.

Key words: oropharynx, syphilis, clinicopathologic features, immunohistochemistry