Subglottic cysts in preterm infants: superficially located cysts versus deeply buried cysts in the mucosa

Purpose To analyze the reason for the diversity of the clinical course of subglottic cysts and discuss their pre- and coexistence with subglottic stenosis. Methods The medical records of patients who were treated for subglottic cysts between 2003 and 2020 were retrospectively reviewed and direct laryngoscopy videos were analyzed to assess the healing patterns of their disease. Results Of the 15 patients, 10 had a history of intubation in the neonatal period. In 11 patients, the cysts were transparent and well defined, and no recurrence of subglottic cysts occurred after the initial surgery. In four patients, the cysts were located deep in the mucosa and did not have the typical appearance of a cyst, but rather of a stenotic segment; all of them had a history of intubation and three of them required laryngotracheal reconstruction. Conclusion Transparent, thin-walled superficial subglottic cysts with healthy surrounding mucosa can easily be treated with endoscopic marsupialization; however, the treatment of deep subglottic cysts can be challenging. The coexistence of subglottic cysts and subglottic stenosis is not rare. We point out the need for considering the possibility of a missed deep submucosal cyst in a seemingly refractory case of pediatric subglottic stenosis with atypical endoscopic findings and with a background history of prior intubation.