Intraductal papillary neoplasm of the bile duct

Figure 2 Schematic drawings of intraductal papillary neoplasms of the bile duct showing the five imaging patterns. A: Type 1: Diffuse duct ectasia with a grossly visible papillary mass; B: Type 2: Diffuse duct ectasia without a visible mass; C: Type 3: An intraductal polypoid mass within localized duct dilation; D: Type 4: Intraductal cast-like lesions; E: Type 5: A focal stricture-like lesion with mild proximal ductal dilation.