Cytologic diagnosis of syphilitic pleuritis: a case report.

We report on a case of a 68-yr-old man with secondary syphilis diagnosed by biopsy of skin lesions, who concomitantly suffered from left lower lobe pneumonia with associated pleuritis. Cytologic examination of the pleural fluid was diagnostic of syphilis, not only by the characteristic cytomorphology but also by demonstration of spirochetes by the May-Grünwald-Giemsa (MGG) and Steiner staining methods. This suggests that the pneumonia was also syphilitic. The patient was seropositive for HIV-I, but this probably did not contribute to the thoracic manifestations of syphilis, as there was no evidence of immunodeficiency by the CD4/CD8 T lymphocyte count. This is the second reported demonstration of Treponema pallidum in a pleural fluid, and the first diagnosed by cytopathologic examination.