Bronchoalveolar Lavage of Pneumocystis carinii Pneumonia: Cytological and Ultrastructural Features

Pneumocystis carinii 폐렴의 기관지 폐포세정액: 세포학적 및 전자현미경적 소견

The cytological and ultrastructural findings of Pneumocystis carinii(PC) obtained from rats by bronchoalveolar lavage (BAL) are described. All developmental forms of the PC organisms were obtained in the lavage fluid. Papanicolaou stain revealed conglomeration of PC as a foamy cast. The cystic walls of PC were well identified on Gomori's methenamine silver stain. Trophozoites and intracystic bodies were stained by Giemsa and Diff-Quik techniques. Some PC organisms were seen within the alveolar macrophages. Ultrastructurally, the cysts were almost circular in shape, and were nearly devoid of surface tubular extensions. The wall of the cyst was composed of an unit membrane, an intermediate electron lucent layer and an external electron dense layer The cysts frequently contained intracystic bodies, so called sporozoites. Occasionally empty or collapsed cysts with no intracystic bodies, and precysts were found. Trophozoites were variable in size and shape with abundant tubular extensions along the single electron dense pellicle. BAL is a useful method for concentrating the various morphologic forms of PC organisms, and is a rapid diagnostic method for PC pneumonia.