Trichomonads in pleural effusion: case report, literature review and utility of PCR for species identification.

Trichomonas tenax is a flagellated protozoan commonly found in the human oral cavity but of unusual occurrence in pulmonary infections. We describe a case of a 67-year-old patient with glioblastoma who presented with severe pleurisy in the post-operative period while she was receiving high-dose corticotherapy. Several motile flagellated protozoa were identified in the pleural fluid. Trichomonas tenax was identified by molecular methods. Pulmonary infections with Trichomonads might be underestimated because of diagnostic difficulties. The utility of molecular biology for species identification is underlined and the pathogenicity of Trichomonad parasites in human lungs is discussed in light of previously reported cases.