Thyroid Goiter, Retrosternal:
View images of thyroid goiter
Clinical:
Substernal goiter is the result of a thoracic extension of a cervical goiter. Because of this, most intrathoracic goiters occur in the superior / anterior mediastinum. Retrosternal goiters account for about 10% of anterior mediastinal masses and affect females more than males (3:1). Between 20 and 25% of the cases actually extend into the posterior mediastinum. Patients are usually asymptomatic, but may present secondary to the mass effect of the lesion on the airway or esophagus.
X-ray:
On plain films an anterior mediastinal mass is seen which typically displaces the trachea. On CT the lesion appears as a sharply marginated, inhomogeneous mass (areas of low attenuation are common secondary to hemorrhage or cyst formation) which demonstrates continuity with the cervical thyroid. Calcification is seen in 25% and is usually curvilinear about areas of hemorrhage.
