A 72-year-old woman was referred for the examination of wall thickening of the bile duct and a polyp-like lesion on the gallbladder. The bile duct and gallbladder lesions were observed to be continuous on abdominal ultrasonography. We performed a bile duct biopsy, and pathological findings showed hyperplasia of the lymphoid follicles without malignancy. We considered these two lesions to be the same lesion, and laparoscopic cholecystectomy was performed to make a definite diagnosis. The pathological examination of the resected gallbladder also showed hyperplasia of the lymphoid follicles. We diagnosed the patient with lymphoid hyperplasia of the gallbladder extending to the bile duct.
Keywords: bile duct; lymphoid follicle; lymphoid hyperplasia.