Discrimination between sclerosing cholangitis-associated autoimmune pancreatitis and primary sclerosing cholangitis, cancer using intraductal ultrasonography. 2011
OBJECTIVE Differentiation of sclerosing cholangitis-associated autoimmune pancreatitis (SC-AIP), primary sclerosing cholangitis (PSC) and cancer of the hilar part of the bile duct (CHB) has been challenging. The aim of the present study was to evaluate characteristic intraductal ultrasonography (IDUS) features that could be used to discriminate SC-AIP from PSC and CHB. METHODS Six patients with SC-AIP, 10 patients with PSC and 12 patients with CHB were identified. We reviewed the following bile duct features observed using IDUS to determine their usefulness for differentiating SC-AIP from PSC and CHB: presence of symmetrical wall thickness, wall thickness, presence of homogeneous internal foci and presence of lateral mucosal lesions continuous to the hilar. RESULTS IDUS results (SC-AIP, PSC, CHB) were as follows: wall thickness (mm), 3.7±0.9, 2.6 ±0.9, 2.8±0.0.6; presence of symmetrical wall thickness, 100% (6/6), 20% (2/10), 8.3% (1/12); presence of homogeneous internal foci, 100% (6/6), 10% (1/10), 8.3% (1/12); and presence of lateral mucosal lesions continuous to the hilar, 83.3% (5/6), 40%(4/10), 25% (3/12). Symmetrical wall thickness of the bile duct, homogeneous internal foci and lateral mucosal lesions continuous to the hilar were detected significantly more often among the patients with SC-PSC than among the patients with PSC or CHB (P<0.05). CONCLUSIONS IDUS findings, such as symmetrical wall thickness, presence of homogeneous internal foci and presence of lateral mucosal lesions continuous to the hilar can facilitate the differential diagnosis of SC-AIP from PSC and CHB.