CT and MRI Manifestations of IgG4-Related Disease in the Abdomen: A Retrospective Review

OBJECTIVE IgG4-RD is an immune-mediated systemic inflammatory disease that affects multiple organs, including in abdomen and pelvis, and presents with various radiologic appearances. The purpose of this study was to review the imaging manifestations of IgG4-RD in the abdomen at Siriraj hospital. METHODS This retrospective study was approved by the IRB of Siriraj hospital. Thirty-five patients diagnosed with IgG4-RD with abdominal involvement in the 17-year period 2003-2020 identified by searching hospital radiology and ICD10 data bases were included. Thirty-three CT and three MRI images, including one patient with a CT at the initial presentation and an MRI at a relapse presentation, were reviewed by a radiologist for the presence of organ involvement. RESULTS A total of 105 abdominal problems were identified among the 35 patients, with many patients having more than one issue. The most common issue was pancreatitis which was diagnosed in 22 patients (62.9%), followed by bile duct in 18 patients (51.4%), retroperitoneum in 16 patients (45.7%) and kidney in 16 patients (45.7%). A minority of patients also had rare liver, mesentery, prostate gland and/or urethral involvement. Various features in each organ were described and characterized. CONCLUSIONS IgG4-related disease in the abdomen or pelvis can present a wide spectrum of clinical and imaging findings. Recognizing the relevant imaging features facilitates the establishment of an effective diagnosis as well as the differentiation of this disease from other benign or malignant conditions.