A Case of IgG4-Related Disease with Duodenitis That Was Difficult to Diagnose Preoperatively

Key Points

• To report a challenging case of IgG4-related disease presenting as duodenitis with atypical diagnostic findings.
• Clinical examination of a 48-year-old female with chronic abdominal pain.
• Upper gastrointestinal endoscopy and imaging tests, including EUS-FNA and contrast-enhanced CT, were performed.
• Pathological examination of biopsy samples was conducted post-surgery.
• Identified moderate inflammation and storiform fibrosis in duodenal tissue after surgical intervention.
• Preoperative tests showed normal IgG4 levels and no detectable IgG4-positive plasma cell infiltration.
• Chronic pancreatitis was initially diagnosed based on imaging, leading to surgical treatment.