ECTOPIC THYROID-TISSUE - RARE DIFFERENTIA L-DIAGNOSIS OF MEDIASTINAL MASSES

The differential diagnosis of soft tissue masses of the anterior media stinum includes cervical goiter extending into the mediastinum, germ-c ell tumors, masses originating from the thymus, lymphoma and sternal t umors. A rare cause is ectopic mediastinal goiter without a link to th e cervical thyroid. We report the case of a 36-year-old female patient with accidental chest X-ray finding of a large mass (O 7 cm) in the a nterior mediastinum. CT showed a hypodense mass with homogeneous enhan cement and calcifications. There was no evidence of invasion in other organs. CT-guided biopsy revealed thyroid tissue. The cervical thyroid was normal in CT, ultrasound and I-123-scintigraphy; no link to the m ediastinal goiter was detectable. Radionuclide uptake in the latter wa s homogeneous, Since malignancy could not be ruled out definitively, t he mass was removed by thoracotomy and a vascular pedicle originating from the mediastinum was found. Pathologic evaluation confirmed the pr eoperative diagnosis of ectopic mediastinal goiter.