Immunoglobulin G4-related Disease

Abstract

Immunoglobulin G4 (IgG4)-Related Disease (IgG4-RD) can cause fibroinflammatory lesions in nearly any organ and lead to organ dysfunction and irreversible damage. In addition to frequent involvement of the salivary glands, lacrimal glands, and/or pancreas, IgG4-RD often affects the chest. Thoracic manifestations include lung nodules and consolidations, pleural thickening, aortitis, and lymphadenopathy. The diagnosis is made after careful clinicopathologic correlation because there is no single diagnostic test with excellent sensitivity or specificity. Biopsy of pulmonary lesions can be useful for distinguishing IgG4-RD from common mimickers. Immunosuppressive regimens, such as glucocorticoids and/or glucocorticoid-sparing agents, form the cornerstone of treatment.

Keywords: Chest; IgG4-related disease; Pulmonary.

Figure 1.

Hilar and mediastinal lymphadenopathy in a 61-year-old male with IgG4-RD. Chest CT axial scan at the level of the aortopulmonary window on soft tissue windows. There is bilateral, mild mediastinal and hilar lymphadenopathy (arrow). In addition, soft tissue surrounds the ascending aorta, consistent with peri-aortitis (arrowhead).

Figure 2.

Fluorodeoxyglucose (FDG)-avid lymphadenopathy in a 77 year-old-male with IgG4-RD. Coronal PET CT demonstrates FDG-avidity in the hilar and mediastinal nodes (arrows).

Figure 3.

Bilateral paravertebral masses in a 61 year-old-male with IgG4-RD. Coronal reformatted image from a Chest CT scan at the level of the thoracic spine on soft tissue windows. There are bilateral paravertebral masses, seen on the right at T8 and T10/11 and on the left at T10/11 (arrows). Biopsy confirmed IgG4-RD.

Figure 4.

Bronchial wall thickening in 61 year-old-male with cough and IgG4-RD. Axial Chest CT scan on lung windows demonstrates diffuse, multifocal nodular thickening of the bronchial walls, best seen in the right middle lobe (arrow).

Figure 5.

Saber sheath trachea in a 65-year-old male with IgG4-RD. There is elongation in the sagittal plane of the trachea relative to the coronal plane.

Figure 6.

Peripheral nodules and consolidation in 69-year-old male with IgG4-RD. Chest CT axial scan at the level of the aortic root on lung windows. There are multiple, bilateral peripheral lung nodules and consolidative opacities, that also extend along the right major and minor fissures, in a perilymphatic distribution that is characteristic of IgG4-RD. The patient denied pulmonary symptoms.

Figure 7.

Septal thickening and right pleural effusion in a 65-year-old male with IgG4-RD. Chest CT axial scan at the level of interventricular septum on lung windows demonstrates smooth interlobular septal thickening (arrow) and a small right pleural effusion. The appearances mimic pulmonary edema. Echocardiogram showed normal cardiac function.

Figure 8.

Pseudotumors of the coronary arteries in a 61-year-old male with IgG4-RD. Chest CT axial scan at the level of the coronary arteries on mediastinal windows. There is soft tissue surrounding the right coronary artery, left anterior descending and circumflex arteries (arrows).

Figure 9A.

Right lacrimal gland enlargement evidenced by a bulge over the patient’s upper lateral right eye.

Figure 9B.

Right lacrimal gland enlargement revealed by simple retraction of the eyelid.

Figure 9C.

Left submandibular gland enlargement in a 16-year-old boy with IgG4-related disease affecting the major salivary glands, lungs, kidneys, pancreas, and biliary tree. Note that the right submandibular gland has been resected - removed for diagnostic purposes.

Figure 9D.

Right parotid enlargement in a 75-year-old woman with IgG4-related disease affecting the major salivary glands, kidneys (interstitial nephritis), and pleura.

Figure 10.

Low power view of IgG4-related pulmonary disease. Note the tumefactive lesion (arrow) (A), extension along the bronchovascular tree (A) (*) and subpleural involvement (B) (arrowhead). An elastic stain highlights the focus of obliterative phlebitis (C) (arrow). An immunohistochemical stain shows a diffuse increase in IgG4+ plasma cells (D and inset).