Superior Herniation of Normal Mediastinal Thymus

Superior herniation of normal mediastinal thymus is a rare cause of anterior neck swelling, and only a few cases are reported in the literature. It clinically presents as a suprasternal swelling in the neck that appears during increased intrathoracic pressure. It is a benign condition that requires clinical and radiological awareness to avoid unnecessary investigations and invasive procedures. Ultrasound is the imaging of choice for the diagnosis, and management is conservative. This is a case report of a three-week-old male neonate who presented with anterior neck swelling and stridor, diagnosed as a case of superior herniation of normal thymus and was managed conservatively.