Fact-sheet: Immunoglobulin Ig G4 related disease
Updated on 02/26/2021 at 2:32 PM
Note : 0/10
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Definition
Lymphoplasmacytic infiltration (IgG4+ plasma cells) that can involve any tissue, leading to fibrosis and sclerosis.
- IgG4-related sclerosing cholangitis: exclusively involving the distal common bile duct, but sometimes diffuse extra- and intrahepatic involvement
- Mikulicz syndrome with hypertrophic sialadenitis and lacrimal gland involvement in 14% of cases
- Retroperitoneal fibrosis: 10% of cases
- Riedel thyroiditis: 8% of cases
- Interstitial lung disease
- Posterior mediastinal lymphadenopathy that can mimic Sarcoidosis in 8% of cases
- Tubulointerstitial nephritis in 8% of cases
- Pseudotumors of the orbit, liver, and ampulla of Vater in 2% of cases.
Clinical features
- Sialadenitis
- Dacryoadenitis
- Autoimmune pancreatitis
- Cholangitis
Laboratory findings
Serum IgG4 level > 1.35 g/L
Ultrasound
Riedel thyroiditis
CT
Morphologic findings:
- Loss of pancreatic lobulations +/- enlargement
- Peripheral pseudocapsule appearance, hypodense (on the pancreatic arterial phase)
MRI
Same as CT + loss of spontaneous T1 FatSat hyperintensity of the Pancreas
Bile duct dilation
"Duct penetrating sign"
(radish-tail transitional zone, persistent good visualization of the duct within the stricture)
Management
Treatment with corticosteroids and immunosuppressants
Differential diagnosis
Sjögren syndrome
