Fig. 1

The first gastroscopy. A Middle section of the esophagus (approximately 30 cm from incisors). When entering the patient’s lower esophagus-cardia entrance (approximately 40 cm from incisors) (B), at this time, we had not found a tumor yet with sufficient steam injection. However, we failed to fully expose the squamous and columnar epithelial junction (SCJ). We turned the gastroscope over to look at the lesser curvature and found the lesion. First, gastric fundus dilation with sufficient gas injection was limited. Then, as shown in C, we found a bleeding spot in the cardia. Through closer observation, we found a lesion in form of a growing ring around the cardia. Because of its contraction, the stomach cavity was narrowed, similar to a gourd neck. The demarcation line (DL) of the lesion was clear, and as it was growing along the lesser curvature distally, the upper part of the stomach was also affected. Its mucosa was rough, protuberant, with spontaneous bleeding and prone to bleeding when touched by the endoscope. Surface structure was similar to papillary and granular. We did not see any obvious erosion, ulcer, or secretion. As shown in D, it seems to be a submucosal tumor with inflammatory changes in the surface mucosa. We switched to narrow band imaging (NBI) and could see that the lesion had DL. E We inserted biopsy forceps by gastroscopy to touch the lesion and verified that the texture of the lesion was stiff. F Position of the gastroscope lens in each panel of this figure