대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Ig G4-related sclerosing disease

Radiologic Findings

Chest radiograph shows consolidation in right upper lung zone.
Chest CT reveals an enhancing mass-like consolidation with internal calcification and peripheral GGO with smooth interstitial thickening and infiltration in right upper lobe. (Internal calcification is thought to sequelae of pulmonary tuberculosis.)
After 2 months, plain chest radiograph shows decreased size of mass-like consolidation in right upper lobe.
The patient didn't have any symptoms except cough and the laboratory test revealed only mild leukocytosis and slightly elevated CRP.
Bronchoscopic biopsy was done in right upper lobe posterior segment. Marked lymphoplasmacytic infiltration with many IgG-and IgG4-positive cells, consistent with IgG4-related sclerosing disease.

Brief Review

Immunoglobulin G4(IgG4)-related disease is a newly recognized fibroinflammatory condition characterized by tumefactive lesions, a dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, storiform fibrosis, and, often but not always, elevated serum IgG4 concentrations. Epidemiologic characteristics shows the majority of patients are men (62 to 83%) and older than 50 years of age.
IgG4-related lung disease can be considered as an IgG4-related sclerosing inflammation along the entire intrapulmonary connective tissue.
IgG4-related disease shows various types of pulmonary manifestations. IgG4-related lung disease can be categorized into four types on the basis of the predominant CT findings: solid nodular, round-shaped ground glass opacity, alveolar interstitial, and bronchovascular.
The first is a solid nodular type. This type was characterized by the presence of a solitary solid lesion larger than 1.0 cm that included a mass. The solid nodular type were initially thought to be primary lung cancer.
The next is a round-shaped GGO type, which was radiologically characterized by multiple round-shaped GGOs. The radiologic findings of this type resembled those of bronchioloalveolar carcinoma.
The third is the alveolar interstitial type, which is radiologically characterized by diffuse GGO, bronchiectasia, and honeycombing. The patients were initially suspected of having nonspecific interstitial pneumonia on the basis of radiologic findings.
The last is the bronchovascular type. Radiologic finding of this type is thickening of bronchovascular bundles and interlobular septa. Sarcoidosis or lymphoproliferative disorders such as multicentric Castleman disease were radiologically suspected in those cases.
Glucocorticoids are typically the first line of therapy. Azathioprine, mycophenolate mofetil, and methotrexate are used frequently as glucocorticoid-sparing agents or remission-maintenance drugs after glucocorticoid- induced remissions.

References

1) Stone JH, Zen Y, Deshpande V. IgG4-related disease. N Engl J Med. 2012; 366:539-551.
2) D. Inoue, Y. Zen, H. Abo,T. Gabata, H. Demachi, T. Kobayashi, et al. Immunoglobulin G4 related lung disease: CT findings with pathologic correlations. Radiology 2009; 251: 260-270.

Keywords

Lung, Non-infectious inflammation,