IgG4-related inflammatory pseudotumor: A systematic review of histopathological features of reported cases

• Published in: Modern rheumatology 2017-03, Vol.27 (2), p.320-325
• Main Authors: Chougule, Abhijit, Bal, Amanjit
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Child; Female; Granuloma, Plasma Cell - immunology; Granuloma, Plasma Cell - pathology; Humans; IgG4; IgG4-related diseases; Immunoglobulin G - immunology; Inflammatory pseudotumor; Male; Middle Aged; Plasma Cells - pathology
• ISSN: 1439-7595; 1439-7609
• DOI: 10.1080/14397595.2016.1206241

Objectives: There is marked inconsistency in reporting the key features of IgG4-related inflammatory pseudotumor (IPT) cases. We aimed to analyze the various aspects of IgG4-related IPTs and to test the performance of the consensus criteria for their diagnosis. Methods: PubMed database was searched for IgG4-related IPT cases. The data regarding patient demographics, clinical presentation, laboratory findings, histopathological features, and treatment response are extracted and are presented here in a descriptive manner. Results: The study included 40 papers describing the clinicopathological features of 83 IPTs in 80 patients. Seventeen cases were diagnosed on biopsies; while remaining were diagnosed on excision specimens. Among these, 50 cases were categorized as highly suggestive and 24 cases as probable for IgG4RD; while nine cases had insufficient histopathological evidence of IgG4RD. Two cases diagnosed on biopsies having insufficient evidence of IgG4RD showed partial or no response to steroids; while 12/14 cases (85.71%) diagnosed on biopsies that were histologically suggestive or probable for IgG4RD showed prompt response to steroids. Conclusion: Many reports have not specifically mentioned the full histopathological findings of IgG4-related IPTs that may hinder in refining the diagnostic criteria of IgG4RD. The IgG4-related IPTs diagnosed on biopsies with requisite features showed prompt response to steroids indicating specificity of histopathological findings in predicting treatment response.