Purpose: To discuss the diverse imaging features of pancreatic and extra-pancreatic lesions of IgG4-related disease (IgG4-RD) on multi-detector CT (MDCT).
Methods: This retrospective study was approved by our institutional research ethics board, and informed consent was waived. From 2008 to 2013, 159 patients including 120 men (mean age 57 years; range 27-79 years) and 39 women (mean age 51 years; range 25-83 years) who met the comprehensive diagnostic criteria for IgG4-RD (2011) were enrolled. MDCT images consisted of 153 abdominal images, 64 pelvic images, 64 thoracic images, and 8 neck images were retrospectively analyzed in consensus by two radiologists with expertise in the CT diagnosis of IgG4-RD.
Results: Only 11 (11/153, 7.2%) IgG4-RD patients had been found with no pancreatic involvement. 145 (145/159, 91.2%) patients had various extra-pancreatic lesions, including involvement of biliary tree (93/153, 60.8%), peri-pancreatic vessels (66/153, 43.1%), IgG4-related lymphadenopathy, peri-abdominal aorta arteritis or retroperitoneal fibrosis, head and neck lesions, etc. Renal lesions were found in 26 (26/153, 17.0%) IgG4-RD patients with 4 types of renal parenchymal involvement. Lung lesions were found in 44 (44/64, 68.7%) IgG4-RD patients, which were classified into 7 types.
Conclusions: Pancreatic and various extra-pancreatic lesions may be involved in IgG4-RD patients frequently with typical imaging findings. It is useful to recognize the atypical or uncommon imaging features to help the diagnosis of IgG4-RD together with other serologic or histopathologic findings.
Keywords: Extra-pancreatic lesions; IgG4-related disease; Multi-detector CT; Pancreatic lesions.