Clinical Spectrum of Mediastinal Cysts: Bronchogenic cysts

Bronchogenic cysts were more common than esophageal cysts. The prevalence of bronchogenic cysts was reported to be 1:42,00 and 1:68,000 of admissions to two hospitals; however, it is difficult to appreciate the prevalence of the cysts exactly, since some aged patients have lesions that remain forever silent.
Bronchogenic and esophageal cysts originate from the ventral primitive foregut as an anomalous budding of the laryngotracheal groove during embryonic development around the time when cleavage occurs between the respiratory tract and digestive tube. Both organs have columnar and ciliated mucosa at the time, and thereafter the squamous epithelium spreads in the esophagus. Gerle et al first proposed the term bronchopulmonary foregut malformation to encompass the entire spectrum of developmental anomalies of the primitive foregut. In a broad sense, congenital cystic lesions of the lung and mediastinum may result from compromised interaction between embryologic mesodermal and ectodermal lung components during development.

Bronchopulmonary foregut malformations encompassed pulmonary sequestration, congenital cystic adenomatoid malformation, congenital lobar emphysema, and bronchogenic pulmonary cyst. During the same period of our 105 mediastinal cysts, we also observed 26 cases of congenital cystic disease of the lung including 13 bronchogenic pulmonary cysts, which were previously reported. The stage of embryonic development and error may determine the bronchial vs pulmonary parenchymal location of bronchogenic cysts. When they form early, they are located in the mediastinum by the trachea or esophagus, having ciliated epithelium derived from either the respiratory tract or alimentary tract. In contrast, when the later anomaly develops, they are located in the lung parenchyma and with lined respiratory epithelium.

Category: Cysts

Tags: bronchogenic cysts, foregut cysts, Japanese experience, mediastinal cysts, mesothelial cysts, symptomatology