CRP and immunoglobulin G4-related sclerosing disease: Indeed, since the imaging findings were not distinctive of a specific pathology, and suspecting an IgG4 Related Disease (IgG4-RD), additional exams were performed: IgG4 serum concentration was found to be elevated (334 mg/dL, with a normal value under 201 mg/dL), together with total IgG (1560 mg/dL in the first occasion and 1720 mg/dL subsequently, with normal values between 650 and 1600 mg/dL); moreover, total IgE was almost 10 times above the upper normal value, and the CRP was only slightly elevated (7 mg/L).