PMC4539450_01
Case 1, endoscopic examination. EGD examination in April 2013 ((a) white-light endoscopy; (b) white-light endoscopy with indigo-carmine dye staining). EGD examination in April 2014, when an initial diagnosis of focal cancer within gastric HP was made ((c) white-light endoscopy; (d) white-light endoscopy with indigo-carmine dye staining). Endoscopic findings after en bloc resection by ESD (e). EGD: esophagogastroduodenoscopy; HP: hyperplastic polyp; ESD: endoscopic submucosal dissection.
CRIGM2015-201042.001.jpg
PMC4539450_01_CRIGM2015-201042.001.jpg
fig1
The EGD performed 3 years later revealed that the gastric HP remained the same size (Figures 1(a) and 1(b)); a biopsy revealed mild dysplasia in the hyperplastic foveolar epithelium of the gastric HP. The following EGD, performed 4 years later, revealed a significant increase in size, to 20 mm, and the lesion was classified as type III (Yamada classification) (Figures 1(c) and 1(d)). The polyp was resected en bloc by endoscopic submucosal dissection (ESD) performed with a hook knife (Figure 1(e)).
Case 1, histopathological findings. (a) Resected specimen obtained by endoscopic ESD (H&E, x4). (b) Foci of tubular adenoma with mild dysplasia (between the arrows) in the setting of HP (between arrowheads) are noted (H&E, x20). (c) Foci of carcinomatous transformation (between red arrows) adjacent to the adenomatous lesion (black arrows) in sequence are observed (H&E, x20). (d) The black box in (c) depicts the position of the enlarged section. Red arrows: foci of carcinomatous transformation; black arrows: adenomatous lesion. ESD: endoscopic submucosal dissection; HP: hyperplastic polyp.
CRIGM2015-201042.002.jpg
PMC4539450_01_CRIGM2015-201042.002.jpg
fig2
The resected specimen revealed well-differentiated adenocarcinoma limited to the mucosa around the elongated, grossly distorted, branching, and dilated hyperplastic foveolae lying in an edematous stroma rich in vasculature and small, haphazardly distributed, smooth muscle bundles with dysplastic foci (Figures 2(a)-2(d)).
PMC4539450_02
Case 2, endoscopic examination. EGD examination in October 2014, when an initial diagnosis of focal cancer within gastric HP was made ((a) white-light endoscopy; (b) white-light endoscopy with indigo-carmine dye staining). Endoscopic findings after en bloc resection by EMR (c, d). EGD: esophagogastroduodenoscopy; HP: hyperplastic polyp; EMR: endoscopic mucosal resection.
CRIGM2015-201042.003.jpg
PMC4539450_02_CRIGM2015-201042.003.jpg
fig3
The polyp was resected by endoscopic mucosal resection (EMR) using a submucosal saline injection technique for reduction of iatrogenic thermal injury, and, to increase the probability of a truly curative complete resection, the polyp was lifted up and removed en bloc with a diathermic loop (Figures 3(c) and 3(d)).
Case 2, histopathological findings. (a) Resected specimen obtained by endoscopic EMR (H&E, x4). (b) The black box in (a) indicates the region shown in the enlarged image. Foci of carcinomatous transformation (between arrows) in the setting of HP are observed (H&E, x20). EMR: endoscopic mucosal resection; HP: hyperplastic polyp.
CRIGM2015-201042.004.jpg
PMC4539450_02_CRIGM2015-201042.004.jpg
fig4
The resected specimen revealed focal well-differentiated adenocarcinoma limited to the mucosa around the hyperplastic foveolae lying in a vascular edematous stroma (Figures 4(a) and 4(b)).