Macroscopic and pathological findings of the resected specimen. (a) Macroscopic findings. Marking clips were endoscopically attached before surgery to the oral and distal ends of the intraepithelial spread of the tumor (arrow head). The white arrow indicates the intramural metastasis. (b, c) Proliferation of the squamous cell carcinoma to the muscularis mucosa layer in the esophagus. (d) Lymphatic invasion of the primary tumor. (e) The intramural metastasis (arrows) was located primarily in the lamina propria mucosa and partly in the submucosal layer. (f) Metastatic lymph node retrieved from the dorsal area of the thoracic aorta. (g) Metastatic lymph node in the perigastric nodes along the left gastric artery. MM, muscularis mucosa; SM, submucosa; MP, muscularis propria.