Clinicopathological characteristics of esophageal squamous papillomas in Japanese patients--with comparison of findings from Western countries.

To clarify the characteristics of esophageal squamous papillomas (ESPs) in the Japanese population, we investigated 38 ESPs of 35 Japanese patients from a file with 17,387 upper gastrointestinal endoscopies in our university hospital. ESPs accounted for 0.20% of the total number of endoscopies and comprised 21 females and 14 males with an average age of 59.2 years. More than half of the ESPs (52.6%) were located in the middle esophagus. The ratio of human papilloma virus (HPV) positive ESPs was 10.5% and all were located in the middle esophagus of female patients only. HPV-positive ESP cases were younger (46.8 years) than HPV-negative cases (60.8 years). Based on comparison with the reports from western countries, we attribute the low prevalence in the lower esophagus to the relatively fewer occurrences of severe reflux esophagitis (RE) due to chronic gastritis with low gastric acid secretion among Japanese patients.