Intrathoracic aberrant thyroid: identification critical for appropriate operative approach.

True aberrant thyroid in the chest is a rarely described entity. More commonly, "aberrant" thyroid is a substernal goiter that is an extension of the cervical gland inferiorly and can be removed safely with the classic "collar" incision. Aberrant intrathoracic thyroid typically derives its blood supply from intrathoracic sources and requires an alternate surgical approach for adequate exposure. The ability to identify these rare intrathoracic thyroids is critical for safe surgical excision.