Tc-99m pertechnetate imaging and CT show bilateral huge cervical and intrathoracic goiter extending to the posterior mediastinum

A patient with goiters had Tc-99m pertechnetate neck and chest images that showed enlargement of both thyroid lobes with mediastinal extension. The intensity of the large areas of diffuse uptake in the mediastinum was less than in the neck. CT imaging showed bilateral thyroid goiters with inferior extension to the posterior mediastinum. These findings corresponded with both a thyroid goiter and with intrathoracic extension into the posterior mediastinal by CT imaging. The patient underwent bilateral total thyroidectomy and right thoracotomy for the resection of the posterior mediastinal goiter. The removed posterior mediastinal goiter measured 7.5 x 5.4 x 4.1 cm and was confirmed to be a multinodular goiter. Although the intensity of radioactivity in the mediastinal goiter was less than that of the cervical goiter, the mediastinal portion of the goiter remained detectable by Tc-99m pertechnetate.