대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

IgG4-related lung disease

Radiologic Findings

Chest radiograph demonstrates a mass-like consolidation in the right upper lung field. Contrast-enhanced axial and coronal CT images show mass-like consolidation of homogeneous density with air-bronchogram and several perilesional nodules and ground-glass opacity (GGO) in the apical segment of right upper lobe.
Despite antibiotic therapy for a week, pulmonary lesions did not show improvement. Histopathology obtained by trans-bronchial lung biopsy showed chronic inflammation with heavy infiltration of lymphoplasma and IgG4 + cells. Serum IgG was 1796 mg/dl (normal range: 700-1600), and IgG4 subclass was 3600 mg/L (30-2010). After steroid therapy, follow-up chest radiograph after 14 days showed markedly decreased mass-like opacity in the right upper lung field.

Brief Review

Immunoglobulin G4 (IgG4)-related disease is a multi-organ disorder that can also involve the lungs. Irrespective of the affected organ, IgG4-related disease is pathologically characterized by diffuse lymphoplasmacytic infiltration, fibrosis, and occasional eosinophilic infiltration. IgG4-related lung disease can present in various forms, which can be categorized into four types based on the predominant CT findings: solid nodular, round-shaped GGO, alveolar interstitial, and bronchovascular. Solid nodular and round-shaped GGO-type lesions can mimic primary lung cancer including bronchioloalveolar carcinoma. The differential diagnoses of bronchovascular-type lesions include lymphoproliferative disorders such as multicentric Castleman disease, sarcoidosis, and lymphangitis carcinomatosa. Alveolar interstitial-type lesions radiologically resemble nonspecific interstitial pneumonia. Based on the radiologic and pathologic correlations, IgG4-related lung disease could be interpreted as an inflammatory lesion distributed along the pulmonary lymphatic system. Serum IgG4 concentration is the most sensitive and specific laboratory test for the diagnosis of IgG4-related disease.

References

1. 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.
2. S.Matsui, A. Hebisawa, F. Sakai, H. Yamamoto, Y. Terasaki, Y. Kurihara, et al. Immunoglobulin G4-related lung disease: Clinicoradiological and pathological features. Respirology 2013; 18, 480-487
3. J.H. Ryu, H. Sekiguchi and E.S. Yi Pulmonary manifestations of immunoglobulin G4-related sclerosing disease. Eur Respir J 2012; 39: 180-186

Keywords

IgG4-related sclerosing disease, Lung,