[A case of hyperplastic polypoid lesion in the common bile duct hard to differentiate from early bile duct carcinoma]

In a 72-year-old male carcinoma of the bile duct was suspected because of an abnormality on laboratory examination. Ultrasound showed the dilatation of extrabiliary duct. Endoscopic ultrasound revealed localized wall thickening of the common bile duct. ERCP demonstrated the dilatation of the CBD. Within the dilated duct a filling defect was present. Histology of the resected specimen disclosed hyperplasia of the epithelium in the CBD.