IgG4 assozierte retroperitoneale Fibrose

Abdominal
manifestations of IgG4-related disease: a pictorial review. Example of IgG4 retroperitoneal fibrosis. a Axial CECT showing enhancing soft tissue partly encasing the IVC and aorta (arrows). b Axial FDG PET/CT showing increased FDG uptake in the abnormal retroperitoneal soft tissue (arrows). c Axial CECT in the same patient, with reduced periaortic soft tissue, following treatment with corticosteroids. d Corresponding T1FS post-contrast MRI showing residual enhancing soft tissue around the aorta following steroid treatment (arrows)
insightsimaging.springeropen.com • CC-by-4.0
Lizenz: CC BY-SA 4.0

IgG4 assozierte retroperitoneale Fibrose

IgG4-assoziierte Erkrankung Radiopaedia • CC-by-nc-sa 3.0 • de

IgG4-related disease (IgG4-RD) is a systemic disease that is characterized by fibroinflammatory infiltration of various organs, including by plasma cells that express IgG4 (immunoglobulin G subclass 4).

Terminology

This condition has been known by many other names in the past, such as IgG4-related sclerosing disease, IgG4-related systemic disease, IgG4-related systemic sclerosing disease, IgG4-syndrome, IgG4-associated disease, and IgG4-related multi-organ lymphoproliferative syndrome. Since 2012, however, IgG4-related disease has become the preferred term .

Epidemiology

IgG4-related diseases are more common in middle age or elderly males.

Clinical presentation

Clinical manifestations vary by the organ involved. These organ systems may be either synchronously or sequentially involved.

Pathology

Location

The disease spectrum is broad across organ systems:

Microscopic appearance

There are three major histopathologic characteristics of IgG4-related disease :

  • dense lymphoplasmacytic infiltrate
  • at least focally storiform fibrosis
  • obliterative phlebitis

Two of these features are required for a confident pathologic diagnosis of IgG4-related disease, with a few organ-specific exceptions . Additional supporting features are non-obliterative phlebitis and eosinophilia .

Immunophenotype

Immunohistochemistry should demonstrate plasma cells that stain for IgG4. IgG4+ plasma cells must account for more than 40% of IgG+ plasma cells . The absolute density of IgG4+ plasma cells (number per high power field) suggestive of the diagnosis varies by organ. For example, the cutoff is >10/hpf for pancreatic biopsy specimens and >100/hpf for lacrimal and salivary glands .

Markers

Serology is often, but not always, abnormal in IgG4-related diseases. A serum IgG4 level >135 mg/dL is supportive of the diagnosis .

Siehe auch:
Assoziationen und Differentialdiagnosen zu IgG4 assozierte retroperitoneale Fibrose:
IgG4-assoziierte
Erkrankung
surgicalcasereports.springeropen.com • CC-by-4.0