Immunoglobulin G4-related Chronic Rhinosinusitis: A Pitfall in the Differential Diagnosis of Granulomatosis with Polyangiitis, Rosai-Dorfman Disease and Fungal Rhinosinusitis

Publication date: Available online 27 December 2017
Source:Human Pathology
Author(s): Yingshi Piao, Yuan Zhang, Changli Yue, Chengshuo Wang, Luo Zhang
Immunoglobulin G4 (IgG4)-related chronic rhinosinusitis (CRS) has recently been proposed to be a new clinical entity of nasal disease, with no consensually agreed criteria for diagnosis. Moreover, the pathological features if IgG4-related CRS often overlap with other sinonasal inflammatory and autoimmune diseases such as Granulomatosis with Polyangiitis (GPA), Rosai-Dorfman disease (RDD) and Fungal Rhinosinusitis (FRS). We aimed to explore the specific similarities and differences in clinicopathologic features between IgG4-related CRS, and GPA, RDD and FRS, in order that these conditions can be diagnosed more accurately. Biopsy specimens collected from nasal mucosa of 20 IgG4-related CRS, 10 GPA, 10 RDD and 10 FRS patients were assessed by haematoxylin and eosin staining and immunohistochemical techniques for specific histochemical differences. The number of IgG4-positive plasma cells /high-power fields (HPF) in biopsies from IgG4-related CRS patients (mean= 79.6±51.59; range= 15/HPF to 230/HPF) was significantly higher than in biopsies from GPA (mean= 13±9.428; p<0.0001) and RDD (mean= 12.5±8.267; p<0.0001) patients, but not from FRS (mean=47.4±26.48; p>0.05) patients. Similarly, the ratio of IgG4/IgG-positive plasmacytes was>40% in 90% (18/20) of IgG4-related CRS patients, compared to >40% in 10% (1/10) GPA patients, 20% (2/10) RDD patients and 20% (2/10) FRS patients. The sinonasal diseases GPA, RDD and FRS might present with similar histopathologic features such as the increased numbers of plasma cells and fibrosis which are characteristic of IgG4-related CRS. A comprehensive consideration combining the clinical signs and symptoms with a histopathological assessment of IgG4- positive plasma cells may provide accurate diagnoses of these conditions.



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