Anterior Mediastinal Mature Teratoma Presenting With Mediastinal Mass Syndrome in a Six-Month-Old Infant: Diagnostic Pitfalls and Anesthetic Challenges.

An anterior mediastinal mass in infants can present with life-threatening complications due to airway and vascular compression. We report a six-month-old infant with a mature teratoma presenting as mediastinal mass syndrome, highlighting the diagnostic challenges and anesthetic risks involved. The patient developed significant respiratory compromise, underscoring the importance of early recognition and cautious perioperative management. Imaging played a central role in diagnosis, while perioperative planning required special consideration because of the risk of airway collapse under anesthesia. This case reinforces the need for heightened clinical suspicion and multidisciplinary coordination when managing mediastinal masses in infants.