A Case of Isolated IgG4-related Cholecystitis Mimicking Gallbladder Cancer

Abstract

A 50-year-old man was admitted to our hospital complaining of epigastric pain. Contrast enhanced CT scan showed thickening of the body and fundus of the gallbladder wall. PET-CT scan showed slightly elevated up-take in the same area (SUVmax 2.9). Diffusion weighted MRI revealed a hyper-intense lesion in the fundus of the gallbladder. A gallbladder tumor mimicking gallbladder cancer was diagnosed. Open cholecystectomy was performed. Histological examination revealed numerous plasma cells and lymphocytes, and immunostaining showed many IgG4-positive plasma cells suspected to represent isolated IgG4-related cholecystitis without malignancy.