Gross mural cartilage in a congenital bronchogenic cyst: MRI features.

An infant who had a cardiac murmur after the delivery was evaluated with echocardiogram. A 1 cm cystic area was incidentally identified in the upper right mediastinum, that was not related with the heart. A 4 x 4.5 x 8 cm cystic mass in the superior mediastinum and lower neck was demonstrated on the magnetic resonance imaging (MRI). At surgery, a small solid structure corresponding to the nodule seen on MRI was identified, which was firm and cartilaginous in nature and attached to the wall of the cyst. Grossly visible cartilage in association with a bronchogenic cyst has not been previously reported. In conclusion, the bronchogenic cysts can have grossly visible cartilage in their wall and extend to extrathoracic spaces in a contiguous fashion, mimicking other entities such as teratomas and cystic lymphangiomas.