Some esophageal diseases such as carcinoma, esophagitis, and collagen diseases have often been reported to show a diffusely thickened esophageal wall in the roentogenogram findings. In the current report, a preoperative upper gastrointestinal series and an endoscopic examination showed a diffusely infiltrative type carcinoma, but other examinations did not suggest any diseases such as esophagitis or collagen diseases which might cause a thickening of the esophageal wall or a constriction of the esophagus. A postoperative histological examination revealed the primary carcinoma to remain only within the mucosal layer, while a large degree of lymphatic vessel permeation reached the adventitia over a wide area. An extraordinary degree of lymphatic permeation spread through the esophageal wall, and stromal fibrosis developed as a result of such lymphatic permeation. These histological phenomena might thus have led to the macroscopic appearance of infiltrative type esophageal carcinoma.