Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is an autosomal-dominant syndrome developing gastric carcinoma with a background of fundic gland polyposis 1 . Although prophylactic total gastrectomy is considered given the high incidence of gastric cancer 2 3 , there is no consensus/guideline. We report a case of treating a pyloric gland adenoma (PGA) in GAPPS with endoscopic submucosal dissection (ESD).
A 54-year-old woman was referred to our hospital with a diagnosis of fundic gland polyps (FGPs). FGPs were localized in the gastric body and fundus ( Fig. 1 ), but there were no polyps in the antrum and duodenum. A 20-mm white elevated lesion was observed in the greater curvature of the upper body. Under narrow-band-imaging magnifying endoscopy, arcuate glandular duct structures were observed, and the demarcation line could be identified ( Fig. 2 ). She had several relatives with gastric cancer; particularly her brother was diagnosed with fundic gland polyposis. Hence, we suspected a gastric-type tumor associated with GAPPS.
Fig. 1.
Endoscopic findings of the stomach (distant view). Fundic gland polyps were observed in the gastric body and fundus, except for the lesser curvature.
Fig. 2.
Endoscopic findings of the tumor. A 20-mm white elevated lesion was observed in the greater curvature of the upper body.
ESD was performed because the patient refused the surgery ( Video 1 ). The lesion was resected en bloc using the clip-and-thread traction method ( Fig. 3 ). The lesion consisted of closely packed neoplastic glands resembling pyloric glands. The tumor exhibited pronounced cytological and architectural atypia in some areas ( Fig. 4 ). Immunohistochemistry revealed diffuse reactivity to MUC6 and focal reactivity to MUC5AC. The histological diagnosis was PGA with high grade dysplasia.
Fig. 3.
Procedure of endoscopic submucosal dissection. The lesion was resected en bloc by the clip-and- thread traction method.
Fig. 4.
Histopathological findings (hematoxylin and eosin staining). a The main lesion was a pyloric gland adenoma (PGA) showing a flat elevation. Two fundic gland polyps were adjacent to PGA. b The PGA was composed of pyloric-type glands. c High grade atypia was noted.
Video 1 A case of treating a pyloric gland adenoma in gastric adenocarcinoma and proximal polyposis of the stomach with endoscopic submucosal dissection.
Genome analysis of the APC gene using peripheral blood demonstrated a point mutation c.-191T > C in exon 1B, a characteristic mutation of GAPPS 4 . The final diagnosis was pyloric gland adenoma associated with gastric adenocarcinoma and proximal polyposis of the stomach.
Although the effectiveness of endoscopic surveillance is unestablished 2 , considering the high risk of carcinogenesis in the residual stomach, close endoscopic follow-up is planned. It is interesting that a white patch in fundic gland polyps as observed in this case is associated with a high rate of proximal gastric cancer in familial polyposis 5 .
Endoscopy_UCTN_Code_CCL_1AB_2AD_3AB
Acknowledgements
We thank Jun Miyoshi for editing a draft of this manuscript.
Footnotes
Competing interests The authors declare that they have no conflict of interest.
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