[Differential diagnosis of early esophagus cancer: endoscopy]

Benign lesions such as leukoplakia, solitary varix, hyperkeratosis, heterotopic gastric mucosa, esophagitis, and dysplasia should be discriminated from esophagus cancer, especially from mucosal cancer (ep-cancer, mm cancer). Those benign lesions can be split into three categories. 1. Lesions to be differentiated by ordinary observation. 2. Lesions to be differentiate by the lugol solution. 3. Lesions to be differentiated by biopsy. These benign lesions except for leukoplakia, solitary varix are not stained by lugol solution (as are not cancer lesions), so biopsy is indispensible. Findings of ep cancer and mm cancer are usually very slight and so could be easily missed in ordinary observation. Therefore when we discern suspective lesions almost imperceptive to a naked eye and unstained by lugol solution, or a slightly raised plateau, vague reddening, discoloration or slight unevenness, detection of esophagus cancer at the earliest stage becomes possible. Differential diagnosis also becomes possible.