A 53-year-old mole acromegalic patient with advanced rectal adenocarcinoma
developed pleuritis in the course of cobalt irradiation, steroid treatment
and chemotherapy. Examination of drained pleural fluid demonstrated numerou
s motile organisms, which were identified as Trichomonas tenax by Giemsa st
aining. Peptostreptococcus micros wets also detected in the cultures of ple
ural fluid and blood. Treatment with metronidazole successfully eliminated
the protozoa and cured the pyothorax.