Diagnosis of pulmonary toxoplasmosis by bronchoalveolar lavage in cardiac transplant recipients.

We report two cases of fatal, clinically unsuspected disseminated toxoplasmosis that developed following orthotopic cardiac transplantation. Toxoplasma gondii trophozoites, pseudocysts, and cysts were best visualized on hematoxylin and eosin and Giemsa-stained cytospin preparations of bronchoalveolar lavage fluid. Post-mortem examination in both cases revealed disseminated toxoplasmosis with extensive involvement of the lungs and heart. The patients, who were seronegative for antibody to T. gondii prior to transplantation, received organs from donors whose serology status was unknown. Demonstration of anti-toxoplasma antibodies post-transplantation occurred in both cases. Bronchoalveolar lavage may be useful in diagnosis of pulmonary toxoplasmosis. Clinicians, pathologists, and cytopathologists must consider T. gondii in the differential diagnosis of pneumonia in the immunocompromised patient, especially cardiac transplant patients.