tomical features. Some squamous cell carcinomas arising from the lower esophagus invade the gastric wall, and, conversely, some gastric adenocarcinomas invade the esophageal wall. It is important to examine the characteristics of invasion of these tumors, because the surgical approach depends on the extent of tumor invasion [1][2][3][4].The purpose of the present study was to elucidate the histological difference between esophageal squamous cell carcinoma with invasion of the gastric wall and gastric adenocarcinoma with invasion of the esophageal wall.
Patients and methodsThirty-six patients with advanced squamous cell carcinoma of the esophagus which had invaded the stomach (esophageal group) and 83 patients with advanced adenocarcinoma of the stomach which had invaded the esophagus (gastric group) were enrolled in this study. We defined advanced carcinomas as tumors deeper than the submucosa. All patients had undergone resection at the First Department of Surgery, Kagoshima University Hospital, between 1980 and 1996. In the 36 patients in the esophageal group, the right thoracoabdominal approach was used in 18, the left thoracoabdominal approach in 13, the transhiatal approach in 4, and the abdominal approach in 1. In the 83 patients in the gastric group, the left thoraco-abdominal approach was used in 53, and the abdominal approach in 30. None of the patients had received radiation therapy or chemotherapy. Early-stage carcinomas were excluded, because the pattern of invasion was confined to the mucosa or submucosa.The resected specimens were treated in a standard fashion throughout the period of the study. To this end, they were fixed on a board after being stretched as far as possible, and the extent of tumor infiltration beyond the Abstract Background. The esophago-gastric junction (EGJ) has several unique anatomical and histological features. We investigated the histological differences between esophageal squamous cell carcinoma with invasion of the gastric wall (esophageal group of patients) and gastric carcinoma with invasion of the esophageal wall (gastric group of patients). Methods. Thirty-six patients in the esophageal group and 83 patients in the gastric group were histologically examined in regard to the mode of invasion. The pattern of tumor invasion beyond the EGJ was classified as continuous or discontinuous. Results. The discontinuous pattern was more frequently seen in the esophageal group than in the gastric group. In the gastric group, however, the distance invaded beyond the EGJ was significantly greater in tumors with the discontinuous pattern than in those with the continuous pattern (P < 0.01). Gastric mucosal invasion at the EGJ was not seen in 36% of the esophageal group, whereas tumor infiltration into the esophageal mucosal layer at the tip beyond the EGJ was found in 60% of the gastric group. The incidence of invasion deeper than the muscularis propria in the gastric and esophageal groups was 18% and 58%, respectively (P < 0.0001). Conclusion. The histological characteristics of eso...