Endoscopic submucosal dissection for adenoma in gastric adenocarcinoma and proximal polyposis of the stomach

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.

Video 1 A case of treating a pyloric gland adenoma in gastric adenocarcinoma and proximal polyposis of the stomach with endoscopic submucosal dissection.

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.

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

Competing interests

The authors declare that they have no conflict of interest.

Acknowledgements

We thank Jun Miyoshi for editing a draft of this manuscript.

• References

• 1 Worthley DL, Phillips KD, Wayte N. et al. Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS): a new autosomal dominant syndrome. Gut 2012; 61: 774-779
• 2 Repak R, Kohoutova D, Podhola M. et al. The first European family with gastric adenocarcinoma and proximal polyposis of the stomach: case report and review of the literature. Gastrointest Endosc 2016; 84: 718-725
• 3 Rudloff U. Gastric adenocarcinoma and proximal polyposis of the stomach: diagnosis and clinical perspectives. Clin Exp Gastroenterol 2018; 11: 447-459
• 4 Li J, Woods SL, Healey S. et al. Point mutations in exon 1B of APC reveal gastric adenocarcinoma and proximal polyposis of the stomach as a familial adenomatous polyposis variant. Am J Hum Genet 2016; 98: 830-842
• 5 Kunnathu ND, Mankaney GN, Leone PJ. et al. Worrisome endoscopic feature in the stomach of patients with familial adenomatous polyposis: the proximal white mucosal patch. Gastrointest Endosc 2018; 88: 569-570

Publication History

Article published online:
27 July 2023