Cross-sectional pictorial review of IgG4-related disease

Abstract

Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune disorder characterized by the infiltration of one or more organs with IgG4-positive plasma cells resulting in inflammatory lesions and fibrosis. Although the pancreas is the most commonly affected organ, involvement of extrapancreatic organs is an increasingly recognized manifestation of the disease. Patients may be asymptomatic and serum IgG4 concentrations may be elevated or normal. Treatment consists of glucocorticosteroid treatment, with excellent response. A definitive diagnosis requires histopathology with imaging playing a key role in avoiding treatment delays. This pictorial review will focus on the most current knowledge regarding IgG4-RD including its common and less common manifestations and the roles of multidetector CT, MRI and ultrasound in the diagnosis and management of suspected IgG4-RD. Knowledge of the varied imaging findings of this multi systemic disease is essential for radiologists to avoid misdiagnosis and assist with timely and effective treatment.

Figure 1.

A 48-year-old female with bilateral upper eyelid swelling. Axial unenhanced CT image shows homogeneously attenuating bilateral masses located external to the lateral rectus muscles in keeping with bilateral symmetrically enlarged lacrimal glands (arrows, a). There is homogeneous isointense swelling of the bilateral lacrimal glands involving both palpebral and deep lobes (arrows) on the T₁ weighted MR image (b), with intermediate signal on the short inversion time inversion recovery image (arrows, c) and avid homogeneous enhancement on the post-gadolinium fat-suppressed MR image (arrows, d).

Figure 2.

The same patient as in Figure 1 presented 1 year later with new neck swelling. There is mild diffuse enlargement of the parotid (asterisk, a) and submandibular (asterisk, b) salivary glands on post-gadolinium fat-suppressed T₁ weighted MR images. The patient returned 2 years later with worsening neck swelling, with sonographic images showing enlarged hypoechoic submandibular glands (arrow, c) with increased vascularity (arrow, d) indicative of sialadenitis.

Figure 3.

A 45-year-old male with left eye pain and proptosis. There is a heterogeneously enhancing soft tissue mass centered in the left orbit extending through the orbital apex into the cavernous sinuses (arrow) on an axial contrast-enhanced axial CT image (A). The mass is isointense on T₁ weighted MR image (arrow, (B), slightly hyperintense on short inversion time inversion recovery MR image (arrow, C), and avidly enhances (arrow) on the post-gadolinium fat-suppressed T₁ weighted image (arrow, D). Biopsy was consistent with IgG4-related orbital pseudotumor.

Figure 4.

A 25-year-old female with tongue deviation and numbness. There is an enhancing soft tissue skull base mass infiltrating the nasopharynx and longus colli muscles (arrow) on enhanced axial CT image of the skull base (a). The mass is low in signal intensity on T₁ weighted MR image (arrow, b), low in signal intensity on T₂ weighted fat-suppressed MR image (arrow, c), with avid homogeneous enhancement on post-gadolinium T₁ weighted fat-suppressed MR image (arrow, d). There is also diffuse avid enhancement of the mucosa of the paranasal sinuses (star), also suggestive of involvement (c, d).

Figure 5.

A 51-year-old male with an incidental finding on CT pulmonary angiogram for shortness of breath. There is a spiculated mass in the left upper lobe (a) and a second mass in the right paratracheal upper lobe (d) both of which demonstrated avid FDG uptake on PET CT (b, e). Biopsy of both masses was consistent with IgG4-related pulmonary pseudotumor. A follow-up CT of the chest 18 months following treatment with corticosteroids demonstrated near-complete interval resolution of the mass in the left upper lobe (c) and right upper lobe mass (f) with residual scarring/fibrosis. FDG, fludeoxyglucose.

Figure 6.

A 48-year-old male with acute coronary syndrome. There is a perivascular cuff of soft tissue encasing the distal left main coronary artery (arrow, a), right main coronary artery (arrowhead, b), and left anterior descending coronary artery on cardiac CT (arrow, b).

Figure 7.

A 45-year-old female with a palpable, non-painful left breast lump. There is an ill-defined hypoechoic mass without posterior acoustic shadowing in the left upper outer quadrant of the left breast on ultrasound (arrow, a). There is a corresponding area of non-mass enhancement in the left upper outer quadrant on post-contrast T₁ weighted fat-suppressed sequences (arrow, b). Biopsy was consistent with IgG4-related sclerosing mastitis.

Figure 8.

A 35-year-old female with elevated lipase and liver enzymes. The pancreas is diffusely enlarged and hypoechoic on ultrasound (asterisk, a). On the axial portal venous CT image, there is diffuse enlargement of the pancreas with loss of definition of pancreatic clefts (“sausage pancreas”) with a low attenuation halo (asterisk, b). The diffusely enlarged pancreas demonstrates homogeneous enhancement on T₁ weighted post-gadolinium sequences (asterisk, c). No pancreatic duct dilatation or peripancreatic fat stranding.

Figure 9.

The same patient was also found to have gallbladder wall thickening (asterisk) and common bile duct wall thickening and dilatation (arrow) on ultrasound (a). There is diffuse mild intrahepatic duct dilatation and dilatation of the common bile duct (arrow) with homogeneously enhancing walls on coronal portal venous phase CT (b) and axial T₁ weighted post-gadolinium sequences (c). Diffuse wall thickening and enhancement of a distended gallbladder is also seen on T₁ weighted post-gadolinium image (arrow, d).

Figure 10.

A 56-year-old male with right upper quadrant pain. There is a hypoechoic lesion in the left lobe of the liver with increased vascularity on Doppler ultrasound (arrow, a). There are multifocal hepatic masses with a mass in the left liver lobe (arrow) and at the liver hilum surrounding the intrahepatic IVC (asterisk, b, c). Both masses demonstrate low central attenuation with a thick rim of irregular peripheral enhancement on arterial phase contrast-enhanced CT (b) without washout on the delayed phase (c).

Figure 11.

The perihilar mass (asterisk) and the mass in the left liver lobe demonstrate intermediate signal on T₂ weighted fat-suppressed sequence (A), low signal on LAVA fat-suppressed sequence (B) with a thick irregular rim of peripheral enhancement on arterial post-contrast fat-suppressed sequence (C) with progressive heterogeneous central enhancement on 5 min delay (D). There is associated diffusion restriction involving the mass in the left liver lobe and the periphery of the hilar mass on diffusion-weighted (E) and ADC images (F). ADC, apparent diffusion coefficient.

Figure 12.

A 35-year-old male with decreased renal function. The left kidney is enlarged and demonstrates decreased cortical echogenicity on ultrasound (a). There is a rind of homogeneous perirenal soft tissue (arrow) on portal venous phase CT (b). The perirenal soft tissue is intermediate to low signal on T₂ weighted fat suppressed sequences (arrow, c), with mild enhancement on fat suppressed post-gadolinium sequences (arrow, d).

Figure 13.

A 32-year-old male with obstructive urinary symptoms. There is a spiculated soft tissue mass (arrow) surrounding the distal right ureter on axial portal venous phase CT (a). Follow-up 12 months later post-treatment demonstrates interval complete resolution of the right periureteric mass on axial contrast-enhanced CT (b).

Figure 14.

A 56-year-old asymptomatic female. There is mass-like soft tissue encasing the left renal artery and ureteropelvic junction (arrow) that demonstrates low signal on axial T₁ weighted in phase sequence (a), low signal on coronal T₂ weighted sequence (B), and mild delayed enhancement on T₁ weighted post-gadolinium coronal image (C). There is resultant chronic left renal atrophy.