Immature mediastinal teratoma in early infancy: report of one case

Immature mediastinal teratomas are rare, found in only 1% of all mediastinal teratomas; those occurring in the neonatal period are even more rare. A male baby suffering from tachypnea, weak crying and hoarseness since birth was noted, from a chest radiograph, to have a superior mediastinal mass. This mass enlarged progressively to an extent that the airway was threatened by one month of age. After resuscitation, intubation and mechanical ventilation, the infant became respirator-dependent. Chest computed tomography and ultrasonography revealed a heterogeneous cystic tissue mass containing focal calcifications. A well-encapsulated tumor, measuring 6 x 4 x 4 cm in size, located anterior to the thymus, was successfully removed at 58 days of age. The pathology showed an immature teratoma. After operation, respiratory distress dramatically improved. However, a superior mediastinal mass reappeared on a chest roentgenogram four months later. After a short course of chemotherapy, the infant received another operation to excise a mass composed of hypertrophic thymic tissue and a small nodular mature teratoma. The patient has remained well for more than nine months now.