What is IgG4-related disease?

IgG4-related disease is a newly recognized fibro-inflammatory condition characterized by:

- tumefactive (swollen) lesions in multiple sites
- characteristic histopathological appearance (see below for detailed description)
- often but not always-elevated serum IgG4 concentrations

An international symposium on IgG4-related disease was held in Boston, MA in October 2011 and attempted to define and classify this new condition.

The diagnosis of IgG4-related disease rests on the combination of characteristic histopathological appearance and increased numbers of IgG4(+) plasma cells.

The critical histopathological features are:

- dense lymphoplasmacytic infiltrate
- storiform pattern of fibrosis (whorled pattern, see example: http://goo.gl/gm4jg)
- obliterative phlebitis

References:

Consensus statement on the pathology of IgG4-related disease. Deshpande V, Zen Y, Chan JK, Yi EE, Sato Y, Yoshino T, Klöppel G, Heathcote JG, Khosroshahi A, Ferry JA, Aalberse RC, Bloch DB, Brugge WR, Bateman AC, Carruthers MN, Chari ST, Cheuk W, Cornell LD, Fernandez-Del Castillo C, Forcione DG, Hamilos DL, Kamisawa T, Kasashima S, Kawa S, Kawano M, Lauwers GY, Masaki Y, Nakanuma Y, Notohara K, Okazaki K, Ryu JK, Saeki T, Sahani DV, Smyrk TC, Stone JR, Takahira M, Webster GJ, Yamamoto M, Zamboni G, Umehara H, Stone JH. Mod Pathol. 2012 May 18. doi: 10.1038/modpathol.2012.72. [Epub ahead of print]
http://www.ncbi.nlm.nih.gov/pubmed/22596100

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