[Pathologic diagnosis of early syphilis in nasal cavity and oropharynx].

Objective: To study the pathologic changes in nasal and oropharyngeal mucosa caused by treponema pallidum (TP) infection.

Methods: Twenty-five cases of nasal and oropharyngeal syphilis were retrieved from the archival files of Department of Pathology of Beijing Tong Ren Hospital collected during the period from June 1996 to September 2005. The hematoxylin and eosin-stained slides were reviewed. Histochemical study using modified Warthin-Starry stain and immunohistochemical study using polyclonal antibody for TP were carried out. The diagnosis of early syphilis was confirmed by rapid plasma regain (RPR) and TP hemagglutination (TPHA) tests.

Results: Among the 25 cases studied, 20 showed neutrophil infiltration, microabscess formation and plasma cell infiltration in the lamina propria. Endothelial swelling of small blood vessels and syphilitic vasculitis was also seen. Tonsillar ulcers associated with abundant plasma cells, lymphocytes and histiocytes were noted in 14 cases. One of which demonstrated florid reactive lymphoid proliferation, with transforming lymphoid cells of various stages identified. Pseudoneoplastic squamous cell proliferation was seen in one case. Spirochetes were detected by modified Warthin-Starry stain in mucosal microabscesses and squamous epithelium in 20 cases, around small blood vessels in 5 cases, and on the surface of tonsillar ulcers in 14 cases. Abundant TP were also found in smears of exudates in 6 cases. TP antigen was detected in 4 cases by immunohistochemical staining. All the 25 cases studied were RPR (1:8 to 128) and TPHA-positive.

Conclusions: Early syphilis involving nasal cavity and oropharynx has distinctive pathologic features. Detailed histologic examination, together with modified Warthin-Starry stain for demonstration of spirochetes, is important to obtain a correct diagnosis.