Endoscopic Submucosal Dissection of an Inverted Early Gastric Cancer-Forming False Gastric Diverticulum

Abstract

Endoscopic submucosal dissection (ESD) is a standard treatment for early gastric cancer (EGC) that does not have any risk of lymph node or distant metastases. Here, we report a case of EGC resembling a diverticulum. Diverticular formation makes it difficult for endoscopists to determine the depth of invasion and to subsequently perform ESD. Because the false diverticulum does not have a muscular layer, this lesion can be treated with ESD. Our case was successfully treated with ESD. After ESD, the EGC was confined to the submucosal layer without vertical and lateral margin involvement. This is the first case in which ESD was successfully performed for a case of EGC that coexisted with a false gastric diverticulum. An additional, larger study is needed to determine the efficacy of ESD in various types of EGC, such as a false gastric diverticulum.

Keywords: Diverticulum, stomach; Endoscopy, digestive system; Stomach neoplasms.

Fig. 1.

Esophagogastroduodenoscopy and endoscopic ultrasound. (A) False gastric diverticulum coexisting with type I+IIc early gastric cancer with a central opening. Spontaneous bleeding and a reddish surface are evident. (B) Forceps biopsies performed three times at the anterior wall, two times at the posterior wall, and three times at the central opening of the main lesion. (C) The invasion of the submucosal layer is unclear because of a previous operation, and no lymph node invasion is observed.

Fig. 2.

Endoscopic submucosal dissection. (A) Precutting incision was first performed around the lesion. After indigo carmine injection, the submucosal layer is blue and has a web-like structure. (B) Injection of an epinephrine and hypertonic saline mixture (1:100,000, 37 mL) into the submucosal layer. (C, D) Dissection of the submucosal layer with an insulation-tipped knife and a hook knife, with a coagulation current of 60 W. (E) The en bloc resected tumor is 5.6×4.7 cm in size and has a central opening with nodular submucosal exposure.

Fig. 3.

Histologic features of the resected specimen. (A) The type I+IIc early gastric cancer coexisting with a diverticulum is a moderately to well-differentiated tubular adenocarcinoma. The tumor size is 3.6×1.8 cm (H&E stain, ×40). (B) The tumor invading the submucosal layer (black arrow). The depth of submucosal invasion is 450 μm. The safety margin of the base is 150 μm (black ink; H&E stain, ×40).