Benign retrosternal or substernal goiters are extensions of a thyroid goiter behind the manubrium sterni. This type of goiter is associated with tracheal and esophageal compression and during surgery may result in injury to the recurrent laryngeal nerve and vocal fold paralysis.

There is almost always continuity with the normally located thyroid gland, attenuation is typically 70-85 HU, and enhancement is intense and persistent. Cysts and calcification may be present.

Malignancy can manifest with local invasion and lymphadenopathy.