Transbronchial fine needle aspiration of bronchogenic cysts.

Transbronchial fine needle aspiration (TBFNA) was used to confirm the diagnosis of bronchogenic cyst in two asymptomatic patients with mediastinal masses who declined surgical exploration. Both masses were located subcarinally but differed in computed tomographic density (7 and 59 Hounsfield units). Aspirate cytology demonstrated predominately bronchial columnar epithelial cells in mucus, without the lymphocytes and polymorphonuclear leukocytes normally seen in intrabronchial secretions. The denser cyst additionally contained some alveolar macrophages with ingested surfactant. While benignity cannot be absolutely assured, it is corroborated by serial evaluation of these patients, which has revealed no interval change in symptoms or roentgenographic size for two and three years, respectively. Under selected circumstances, it appears that TBFNA can be used to extend bronchoscopic diagnosis to benign mediastinal masses if the cytologic features of such aspirates are unique.