Type:
Educational Exhibit
Keywords:
Inflammation, Comparative studies, PET-CT, MR, CT, Head and neck
Authors:
H. Tames1, L. Fajardo2, J. Takahashi2, R. Murakoshi2, M. Sarpi2, C. toyama2, B. C. Olivetti2, R. L. E. Gomes3, E. M. M. Gebrim2; 1São Paulo, SAO PAULO/BR, 2São Paulo/BR, 3Sao Paulo, SP/BR
DOI:
10.1594/ecr2018/C-3058
Background
Immunoglobulin G4-related disease (IgG4-RD) is a systemic condition characterized by tumefactive lesions,
an extensive lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells,
fibrosis of unknown etiology and elevated serum IgG4 concentrations that affect a wide variety of organs [1].
This condition was not recognized as a systemic disease until 2003,
when Kamisawa [2] reported multiple extrapancreatic lesions in patients with autoimmune pancreatitis and the histopathology identified with affected organs was identical to that found in the pancreas.
They proposed the existence of an entity that was later termed "IgG4-related disease" [3].
The radiologist should be aware of the patterns of disease involvement and other inflammatory and neoplastic conditions,
which may exhibit similar imaging findings.
IgG4-RD is generally very glucocorticoid sensitive,
especially in the initial stages.
The prevalence of various organs manifestations remains unclear,
but autoimmune pancreatitis,
sialoadenitis and IgG4-related retroperitoneal fibrosis are the most common disease features.
The typical patient with IgG4-RD is a middle aged to elderly man.
For autoimmune pancreatitis the male to female ratio is 3:1,
contrasting with classic autoimmune diseases in which female outnumber male patients in 9:1.
In head and neck involvement,
however,
the proportion of male and female patients are roughly equal [4].
Involvement of the head and neck region by IgG4-RD is common,
occurring as part of systemic disease or in isolation.
Clinical symptoms vary widely depending on the affected organs,
as a result of organomegaly or hypertrophy and organ dysfunction caused by cellular inflammation or fibrosis.
[5].