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(26 children and 6 adults) presented dyspnea, 27 (24 children, 3
adults) had fever, 7 (six children, 1 adult) were malnourished,
and 5 children had moaning. Chest pain was related in 3 adults.
Emaciation was described in 2 adults. One child with a history
of chronic aspiration and recur rent pneumonia revealed finger
clubbing on physical examination. Four adult patients were
asymptomatic, and the diagnosis was made incidentally during
routine radiological examinations. Cough, dyspnea, and fever
were statistically more frequent in children, and chest pain was
more frequent in adults. The other clinical findings were not
different between the 2 groups (
F6 Fig. 6AQ7 ).
High-resolution CT in exogenous lipoid pneumonia most
commonly shows air-space consolidation, ground glass opaci-
ties, crazy-paving pattern, interlobular septal thickening, and
airspace nodules or mass-like lesions.
2,5,10,12
The most charac-
teristic finding on CT is the presence of a low-density con-
solidation (j30 to j150 HU).
1Y5,7,8,10,15
In our study, the most common HRCT findings were
bilateral air-space consolidations with air bronchogram, areas of
ground glass attenuation, air-space nodules, and crazy-paving
pattern. The patients had no pleural effusion, lymph node
enlargement, or any other chest abnormality. Areas of negative
attenuation within the consolidations were seen in 23 patients,
with values ranging from j17 to j114 HU. In 43 patients the
air-space consolidation was the predominant abnormality seen,
and in 8 patients, the crazy-paving pattern was predominant. In
the remaining 2 patients, diffuse ground glass opacities and
centrilobular nodules were the main findings on CT.
High-resolution CT showed bilateral abnormalities in 51
cases. The features predominated in the right lung in 35 patients,
affected both lungs equally in 15 patients, and predominated in
the left lung in only 3 patients. Abnormalities predominated
posteriorly in 48 cases, had a random distribution in 4 cases, and
in only 1 case predominated in the anterior zones. The most
severely involved lobes (more than 50% of the lobe) were, in
order of frequency, the right lower lobe, the left lower lobe, and
the right upper lobe. The remaining pulmonary lobes infre-
quently showed extensive alterations (right middle lobe, lingula,
and left upper lobe). Lee et al,
11
in a review of HRCT findings in
25 patients with lipoid pneumonia, found that the disease
involved multiple lobes in 22 cases (especially right middle and
both lower lobes), usually located at dependent portions of the
lung (n = 18). Gondouin et al
3
found that the radiological images
were much more frequently bilateral (79%) and affected left and
right lungs equally (95% and 89%). The lesions were often
multilobular and, in particular, quadrilobular.
Our study has some limitations. First, the study was
retrospective; second, the HRCT techniques varied widely, given
the long period (14 years) covered by the study and the different
institutions involved in the survey. Despite these limitations, this
study included the largest series of patients with exogenous
lipoid pneumonia after aspiration of mineral oil for constipation,
all with bronchoalveolar lavage or histological confirmation. In
addition, it is, to our knowledge, the first study to compare the
findings of lipoid pneumonia in adults and children.
In conclusion, our study showed that the most common
HRCT findings in exogenous lipoid pneumonia were bilateral
air-space consolidation with air bronchogram, areas of ground
glass attenuation, crazy-paving pattern, and air-space nodules.
These lesions predominated in the right upper lobe and in lower
lobes; the posterior regions of the right lung were the most
commonly affected. The presence of air-space consolidation, the
involvement of upper right lobe, and the central and posterior
distribution of the lesions were more common in children,
whereas the crazy-paving pattern and random localization were
significantly more frequent in adults. We did not find any
explanations for the difference of the lesions distribution
between children and adults, except for the fact that the right
upper lobe is the most commonly affected in children, especially
in infants, possibly because they spend most of their time in the
supine position, which facilitates lodging of the aspirate to that
lobe. Ground glass opacities, air-space nodules, and involve-
ment of the left upper lobe and both lower lobes were not
different between the 2 groups.
ACKNOWLEDGMENTS
The authors thank Prof. Luis Guillermo Coca Velarde, from
the Department of Biostatistics and Mathematics, Fluminense
Federal University, for the statistical analysis of our data and
Prof. Selma Sias, from the Department of Pediatrics, Fluminense
Federal University, who contributed with cases to this study.
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