{'fraction_non_alphanumeric': 0.030012004801920768, 'fraction_numerical': 0.01680672268907563, 'mean_word_length': 5.95, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Carcinoma in situ of the perihilar bile duct diagnosed by peroral cholangioscopy

A 72yearold man was referred to our institution for evaluation of obstructive jaundice. Blood tests revealed elevated levels of hepatobiliary enzymes and CA199 (CA199: 196 U/mL). Contrastenhanced computed tomography (CECT) revealed wall thickening of the perihilar bile duct, causing proximal dilation of the intrahepatic bile duct (Figure 1A). On magnetic resonance cholangiopancreatography (MRCP), a complete occlusion of the hilar bile duct was observed (Figure 1B). Endoscopic ultrasonography (EUS) demonstrated a hyperechoic lesion with acoustic shadowing consistent with a stone and hypoechoic wall thickening in the perihilar bile duct (Figure 1C). Endoscopic retrograde cholangiopancreatography (ERCP) revealed a defect in the perihilar region