Retrosternal and Intrathoracic Goiter

Abstract

Thyroid mass is nott unusual finding below the level of the thoracic inlet. Tt has been estimated to comprise 5.8% of all mediastinal lesions, according to the level of extension it can be classified i11lo: substernal (80%), partial. intrathoracic (15%), or complete intrathoracic (2 to 4%).

Most of substernal goiters have been reported to occur m the anterior compartrnent, the pathology in most cases vvas non-toxic multinodular goiter. The incidence of malignancy is infrequent.

The diagnosis ts mainly radiological, standard radiography of the neck and chest is most often diagnostic, with evidence of tracheal or oesophageal deviation. Computed tomography pl<Jys an essential role in the diagnosis especially in case of partial or complete intrathoracic goiters. MRT can be used but has many clisaclvantages as the higlt cost, lirnitecl availability and long examination time.

Thyroid scintigraphy us1ng 99'11Tc-pertechnetate or raclioacti ve lod i ne 1231 or 13 1 1 is used for evaluation of thyroid size and morphology, for detection of its function, . degree of retrosternal extension and the presence of functional metastasis. 1t has the advantage of long plasma half•life of 8 clays resulling in high patient radiation dose.