Gastric cancer in a patient with IgG4-related disease: Importance of diligent interpretation of [18F]FDG PET/CT

Document Type : Case Report

Authors

1 Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

2 Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran

3 Cancer Research Center, Razavi Hospital, Imam Reza International University, Mashhad, Iran

Abstract

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder that can involve multiple organs, including the retroperitoneum. We report the case of a 58-year-old man with IgG4-related retroperitoneal fibrosis (IgG4-RPF) diagnosed a decade earlier and initially managed with corticosteroids and azathioprine. Over the years, he developed a range of symptoms that ultimately led to the diagnosis of gastric cancer following complaints of dyspepsia. This case underscores both the diagnostic value and limitations of [18F]FDG PET/CT in IgG4-RD, particularly its inability to reliably distinguish inflammation from malignancy. Although [18F]FDG PET/CT is commonly used to monitor the inflammatory activity of IgG4-RD, this case highlights its potential role in detecting concurrent malignancies. It also emphasizes the critical importance of vigilant screening and long-term follow-up in this patient population.

Keywords

Main Subjects

References

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