Ectopic Thymic Tissue Presenting as an Epiglottic Mass Compromising a Neonatal Airway: A Case Report.

An epiglottic mass (EM) is rarely found in neonates and poses life-threatening airway complications. We present the case of an infant urgently transferred from Belize via the World Pediatric Project with a lingual EM. The EM was misdiagnosed twice. The patient's home country of Belize initially misdiagnosed the EM as an elongated uvula and then again as an esophageal polyp. The true nature of the upper airway mass (UAM) was only discovered intraoperatively on rigid bronchoscopy as a lingual, mobile EM. Pathology of the lingual EM showed fibrovascular tissue with an area of exuberant capillary proliferation, cartilage, and ectopic thymic tissue. A second, smaller mass was also discovered in the left piriform sinus. The pathology revealed the presence of fibrovascular tissue, mucus glands, and a small amount of skeletal muscle. To the best of our knowledge, a thorough review of the literature reveals that this is the first description of ectopic thymic tissue presenting as an EM.