IgG4-positive plasma cells in cutaneous Rosai-Dorfman disease: an additional immunohistochemical feature and possible relationship to IgG4-related sclerosing disease

• Published in: Journal of cutaneous pathology Vol. 36; no. 10; pp. 1069 - 1073
• Main Authors: Kuo, Tseng-tong, Chen, Tse-Ching, Lee, Li-Yu, Lu, Pei-Hsuan
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-10-2009; Wiley-Blackwell
• Subjects: Biological and medical sciences; Dermatology; Hematologic and hematopoietic diseases; Histiocytosis, Sinus - immunology; Histiocytosis, Sinus - metabolism; Histiocytosis, Sinus - pathology; Humans; Immunoglobulin G - blood; Immunoglobulin G - immunology; Immunohistochemistry; Medical sciences; Other diseases. Hematologic involvement in other diseases; Plasma Cells - immunology; Plasma Cells - metabolism; Plasma Cells - pathology; Skin Diseases - immunology; Skin Diseases - metabolism; Skin Diseases - pathology; Immunohistochemistry; Anatomic pathology; Rosai Dorfman disease; Skin disease; Sinus histiocytosis; Dermatology; IgG4; Hemopathy; Plasmocyte
• ISSN: 0303-6987; 1600-0560
• DOI: 10.1111/j.1600-0560.2008.01222.x

Background: Cutaneous Rosai‐Dorfman disease (CRDD) shares the histopathological features of abundant plasma cells and stromal fibrosis with IgG4‐related sclerosing disease. The possible role of IgG4+ plasma cells in CRDD was investigated.
Methods: Twelve cases of CRDD were reviewed, and their lesions were immunostained with anti‐IgG4 and anti‐IgG antibodies. The number of IgG4+ and IgG+ plasma cells and their ratios were estimated. Serum IgG4 and IgG concentrations were measured in two recent cases.
Results: Many IgG4+ and IgG+ plasma cells were found in all 12 cases. IgG4+ plasma cells ranged from 21 to 204 per high‐power field (HPF) (mean 117/HPF), and IgG+ plasma cells ranged from 114 to 759/HPF (mean 349/HPF). All cases had more than 30 IgG4+ cells/HPF, except one case. The IgG4/IgG ratio ranged from 16% to 51% (mean 34%). Serum IgG4 concentration and serum IgG4/IgG ratio were increased in one recent case. Various degrees of stromal fibrosis were present in all cases.
Conclusions: The presence of many IgG4+ plasma cells and stromal fibrosis suggests that CRDD may be related to IgG4‐related sclerosing disease. Many IgG4+ plasma cells is another feature of CRDD, and serum IgG4 may be elevated.