PMC5399199_01
Endoscopic image of the ampulla of Vater performed three years prior. A small protrusion was found on the anal side of the ampulla of Vater.
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A small, protruding lesion had been observed on the anal side of the ampulla of Vater since the first check-up (Fig. 1), but no endoscopic biopsy or a more detailed examination had been performed because the lesion was small and asymptomatic.
Endoscopic image of the ampulla of Vater performed three months before endoscopic therapy. The protrusion was larger than three years prior.
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The protruding lesion was enlarged in the latest EGD (Fig. 2), and endoscopic biopsy was conducted.
Multi-detector computed tomography view. A small tumor 10 mm in diameter was located in the second portion of duodenum and was weakly enhanced with contrast medium (arrowhead).
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MDCT (Fig. 3). MDCT also revealed a smooth pancreatic duct just beneath the ampulla of Vater (Fig. 4), and we decided not to perform magnetic resonance cholangiopancreatography because it was not considered to be able to provide more information about the pancreatic duct.
Multi-detector computed tomography coronal view. A smooth pancreatic duct just beneath the ampulla of Vater was clearly found (arrowhead).
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MDCT (Fig. 3). MDCT also revealed a smooth pancreatic duct just beneath the ampulla of Vater (Fig. 4), and we decided not to perform magnetic resonance cholangiopancreatography because it was not considered to be able to provide more information about the pancreatic duct.
Endoscopic ultrasonography image. A tumor (arrows) was located within the mucosa or submucosal layer, apart from the muscularis propria (arrowheads).
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A 1.0x0.6 cm iso-echoic homogenous tumor was found to be located within the submucosal layer with EUS (Fig. 5).
A smooth-surfaced protruding lesion was found on the anal side of the ampulla of Vater in hypotonic duodenography (arrowheads).
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A smooth-surfaced protruding lesion was observed on the anal side of the ampulla of Vater in hypotonic duodenography (Fig. 6).
Endoscopic papillectomy for G1 NET of the ampulla of Vater. (a) Endoscopic snare papillectomy. (b) Immediate bleeding after papillectomy. (c) Endoscopic hemostasis using bipolar hemostatic forceps. (d) A plastic stent was placed in the pancreatic duct, but a biliary stent could not be placed.
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A plastic stent was placed into the pancreatic duct to prevent pancreatitis, but as we could not identify the opening of the bile duct, a biliary stent for the common bile duct could not be placed (Fig. 7).
Low-power (x10) histological view of the resected specimen. The tumor size was 1.0x0.6 cm in diameter.
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The histological diagnosis of the resection specimen was 1.0x0.6 cm low grade (G1) NET (Fig. 8).
Immunochemical histology of the resected specimen (x200). (a) Positive synaptophysin staining. (b) Positive CD56 staining. (c) Positive chromogranin A staining. (d) The Ki-67 index was less than 2%.
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Immunochemical histology showed positive synaptophysin staining, positive CD56 staining, positive chromogranin A staining, and a Ki-67 index of <2% (Fig. 9).