Computed tomographic features of 23 sporadic cases with Legionella pneumophila pneumonia.
OBJECTIVE
To describe the chest computed tomographic (CT) findings of Legionella pneumophila pneumonia.


METHODS
CT scans obtained from 23 sporadic cases of L. pneumophila pneumonia were retrospectively reviewed. Chest CT findings were analyzed with regard to the patterns and distributions of pulmonary abnormalities. We also analyzed the histopathology of lungs from guinea pigs with experimentally induced L. pneumophila pneumonia.


RESULTS
Consolidation and ground-glass opacity (GGO) were the main findings of CT scans in L. pneumophila pneumonia. The distribution of opacities was categorized as non-segmental (n=20) and segmental (n=4). Non-segmental distribution may follow an onset of segmental distribution. Pleural effusion was observed in 14 (58.3%) patients, of which 13 were accompanied with non-segmental distribution. Abscess formation was observed in only one immunocompromised patient. In the animal pneumonia model, the lesions comprised of terminal bronchioles, alveolar spaces, and interstitia. Small bacilli were observed to be contained by many macrophages within the alveoli.


CONCLUSIONS
Non-segmental distribution was significantly more frequent than segmental distribution in L. pneumophila pneumonia. It is possible that L. pneumophila infection initially results in segmental pneumonia, which progresses to typical non-segmental distribution.
Yu
Hui
H
Department of Respiratory Diseases, Shanghai Pneumology Hospital, Tongji University, Shanghai, China.
Higa
Futoshi
F
Hibiya
Kenji
K
Furugen
Makoto
M
Sato
Yoko
Y
Shinzato
Takashi
T
Haranaga
Shusaku
S
Yara
Satomi
S
Tateyama
Masao
M
Fujita
Jiro
J
Li
Huiping
H
D000328:Adult; D000368:Aged; D000818:Animals; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007877:Legionnaires' Disease / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*