Esophageal squamous cell papilloma, suspected of squamous cell carcinoma

A 46-year-old male without any subjective complaints was diagnosed by radiography as having one polypoid lesion at the distal esophagus. Endoscopy indicated a semipedunculated polyp about 1 cm in size, the specimens of which included atypical cells with a high N/C ratio in the submucosa. Squamous cell carcinoma of the esophagus was suspected. Cytological studies of PAS, CEA and keratin staining to atypical cells were all negative, with Lugol solution staining of the tumor. After polypectomy the lesion was diagnosed as a squamous cell papilloma of the esophagus; and the atypical cells were determined to be immature fibroblasts and/or endothelium.