[6 para-esophageal cysts. Discussion on their origins].

Para-oesophageal cyst is a rare lesion which can be classified, by its origin, as a gastrointestinal duplication. It is mostly encountered in children. Since 1977, we have observed 6 cases in adults, and 5 out of 6 presented as postero-inferior mediastinal tumors. Pre-operative diagnosis is difficult: when the lesion is intramural, the only other diagnosis is leiomyoma; in other cases, a bronchogenic cyst or a posterior mediastinal enteric formation can be discussed. Surgical findings and histological criteria allow a precise definition of these cysts, which lie at least partially in the wall of the oesophagus. There was a histological association of respiratory mucosa and musculosa, either of type or associated with cartilaginous islets. The definition of the clinical classification is easier with a good knowledge of the histogenesis.