Squalene-induced extrinsic lipoid pneumonia: serial radiologic findings in nine patients.
OBJECTIVE
The purpose of this work was to demonstrate the initial and follow-up radiologic findings of squalene-induced extrinsic lipoid pneumonia.


METHODS
Follow-up chest radiographs (n = 9) and high-resolution CT scans (n = 3) as well as initial radiographs (n = 9) and CT scans (n = 8) were obtained in nine patients with squalene-induced extrinsic lipoid pneumonia. The serial radiologic findings were analyzed retrospectively by three chest radiologists, focusing on the pattern and distribution of parenchymal abnormalities.


RESULTS
The most frequent pattern of parenchymal abnormalities on chest radiograph was areas of ground-glass opacity (n = 9, bilateral 6), followed by consolidation (n = 7, bilateral 3) and poorly defined small nodules (n = 4, bilateral 2). The abnormalities were distributed in the right lower lung (n = 9), left lower lung (n = 6), and right middle lung (n = 6) zones. Initial CT scans (n = 8) demonstrated bilateral areas of ground-glass attenuation (n = 8), poorly defined centrilobular nodules (n = 8), crazy paving (n = 6), and consolidation (n = 3). The abnormalities were distributed in the right middle lobe (n = 8) and in both lower lobes (n = 5). Follow-up chest radiograph (n = 9) showed complete disappearance (n = 2) and decrease (n = 7) in the extent of the parenchymal abnormalities. Follow-up CT scans (n = 3) demonstrated decrease (n = 2) and no change (n = 1) in the extent of the abnormalities.


CONCLUSIONS
Squalene-induced extrinsic lipoid pneumonia most commonly appears as areas of ground-glass attenuation mixed with poorly defined centrilobular nodules and crazy paving on CT, being distributed mainly in the right middle and both lower lobes. The lesions are indolent and remain after cessation of squalene ingestion.
Lee
J Y
JY
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Lee
K S
KS
Kim
T S
TS
Yoon
H K
HK
Han
B K
BK
Han
J
J
Chung
M P
MP
Kwon
O J
OJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002648:Child; D005260:Female; D005395:Fish Oils / Q000009:adverse effects; D005500:Follow-Up Studies; D006801:Humans; D008099:Liver; D008297:Male; D008519:Medicine, Traditional; D008875:Middle Aged; D011017:Pneumonia, Lipid / Q000139:chemically induced / Q000000981:diagnostic imaging*; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D012754:Sharks; D013185:Squalene / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods
D005395:Fish Oils; D013185:Squalene