PMC5575439_01
Computed tomography (CT) showed diffuse enlargement of the common bile duct and a mass in the distal bile duct (black arrow) (Fig1a). PET-CT showed increased FDG accumulation (SUVmax: 4.5) in the distal bile duct mass (black arrowhead) (Fig. 1b).
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Computed tomography (CT) demonstrated enlargement of the intra- and extrahepatic bile ducts and stenosis of the distal bile duct (Fig. 1a). PET-CT showed increased FDG accumulation (SUVmax: 4.5) in the distal bile duct mass (Fig. 1b).
Endoscopic ultrasonography showed a 10 mm hypoechoic mass in the stenotic region of the distal bile duct (white arrowhead).
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Endoscopic ultrasonography showed a hypoechoic mass, 10 mm in diameter, at the distal bile duct (Fig. 2).
Endoscopic retrograde cholangiopancreatography showed stenosis of the distal bile duct (white arrow).
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Endoscopic retrograde cholangiopancreatography (ERCP) showed stenosis of the distal bile duct (Fig. 3).
Histopathology of the 18 x 14 x 12 mm distal bile duct mass (black arrow).
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The cut surface of the surgical specimen demonstrated a nodular invasive tumor, measuring 18 x 14 x 12 mm, located in the distal bile duct (Fig. 4).
Hematoxylin and eosin staining revealed a composit carcinoma consisting of adenocarcinoma and non-adenocarcinoma elements (a, white arrow: tub2. b, black arrow: muc. c, black arrowhead: NEC) (Fig. 5a). The non-adenocarcinoma component stained positive for synaptophysin (Fig. 5b) and chromogranin A (Fig. 5c). The Ki-67 index was 37% (Fig. 5d).
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Hematoxylin and eosin staining revealed a carcinoma composed of adenocarcinoma and non-adenocarcinoma elements, with each element occupying more than 30% of the tumor (Fig. 5a). The non-adenocarcinoma component stained positive for synaptophysin and chromogranin A (Fig. 5b,c). In addition, 37% of cells stained positive for Ki-67 (Fig. 5d).