Jina Park MD, Presenter: Nothing to Disclose

Yo Won Choi MD, Abstract Co-Author: Nothing to Disclose

Dong Ho Shin, Abstract Co-Author: Nothing to Disclose

Jae-Sook Ryu, Abstract Co-Author: Nothing to Disclose

To evaluate CT findings of pulmonary visceral larva migrans caused by Toxocara canis and to correlate the CT findings with laboratory features.

Chest CT scans of 25 patients (21 men and 4 women; mean age, 51.5 years) with pulmonary abnormalities on CT and ELISA results positive for Toxocara canis were retrospectively assessed by two chest radiologists in terms of ground-glass opacity (GGO), consolidation, nodules, thickening of bronchovascular bundles, interlobular septal thickening, crazy-paving pattern, subsegmental atelectasis, bronchiectasis, honeycombing, enlarged hilar/mediastinal lymph nodes, pleural effusion, and pericardial effusion. The distribution (central vs peripheral predominant; upper vs lower lung predominant) and extent of pulmonary parenchymal abnormalities were also evaluated. Among the 25, 18 (72%) had peripheral eosinophilia and 23 (92%) had a recent history of eating raw bovine or canine liver. We analyzed the correlation between the total number of pulmonary abnormalities and laboratory findings including the absolute count and percentage of peripheral blood eosinophil, IgE level, and ELISA value, taken less than 15 days before/after the CT, using Spearman correlation.  

Chest CT most commonly showed nodules (n=20, 80%) with (n=17, 68%) or without a halo (n=3, 12%), followed by GGO (n=16, 64%), subsegmental atelectasis (n=8, 32%), and consolidation (n=4, 16%). Nodules were usually of less than 5 mm (n=15, 60%) or of 5 to 10 mm in diameter (n=11, 44%) but those > 10 mm were seen in only two patients (8%). These parenchymal abnormalities showed peripheral (n=25, 100%) and lower lung (n=21, 84%) predominance, and mostly occupied less than 5% of the total lung area (n=24, 96%). The percentage of peripheral eosinophils significantly correlated with the total number of parenchymal abnormalities on chest CT scan (p=0.043).  

Patients with pulmonary toxocariasis usually show pulmonary nodules of less than 1 cm in diameter, GGO, consolidation, or subsegmental atelectasis on CT. Those patients may not show peripheral eosinophilia, a common clue to the diagnosis, if pulmonary abnormalities are small in number.

Pulmonary toxocariasis usually shows nodules and GGO of peripheral lower lung predominance. Patients with such pulmonary abnormalities small in number may not show peripheral eosinophilia.

Park, J, Choi, Y, Shin, D, Ryu, J, Pulmonary Visceral Larva Migrans Caused by Toxocara Canis: CT Findings and Their Correlation with Laboratory Features.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12031906.html