A case report of substernal thyroid cancer requiring tracheal resesction and reconstruction

Intrathoracic goiter or substernal goiter is a tumor usually arising from a lower pole of the thyroid gland and extending to the anterior superior mediastinum. In our patient, the diagnosis of intrathoracic goiter was established with CT, MRI and arteriography. Transtracheal needle aspiration cytology suggested malignancy involving the tracheal wall, so median sternotomy was performed through a cervical collar incision for removal of the tumor. The tumor was found unexpectedly to be in the right lobe of the thyroid gland and was invading the tracheal wall. Right hemi-thyroidectomy with circular resection (4 rings) and reconstruction of the trachea was performed. This experience showed that the thyroid gland may be located behind the sternum in a patient with a short neck and that cancer in such a thyroid may be misdiagnosed as intrathoracic goiter. Therefore, a cautious approach is required for the establishment of the correct diagnosis.