Ectopic Mediastinal Thyroid Tissue with a Normally Located Thyroid Gland

Abstract

Ectopic thyroid tissue (ETT) is a rare entity and a challenging differential diagnosis. This is a report of a case of a mediastinal mass that was found to be an ectopic mediastinal thyroid tissue, in a 77-year-old woman who was admitted to our hospital for breast cancer management. The mediastinal mass was identified in the postsurgical computed tomography (CT) scan of the chest and was suspected as mediastinal lymph node metastasis. A CT-guided percutaneous transthoracic punch biopsy (CT-TPB) proved to be an adequate diagnostic tool to exclude malignancy and provide a definite diagnosis of the mediastinal mass. We find that CT-guided punch biopsy as a useful diagnostic alternative enabling histopathological specimens to be obtained from mediastinal masses and lymph nodes suspected of malignancy.

Nodular hyperplasia presenting as a mediastinal mass

“…In the literature investigation, we found that the CT features of the masses in the present cases were very similar to those of mediastinal ectopic thyroid reported in previous studies. [ 4 , 5 ] US and CT performed in the previous and present reports showed the mediastinal lesions as discrete masses with a mild mass effect. In addition, these lesions showed inhomogeneous enhancement on contrast-enhanced CT images.…”

A Case of Ectopic Thyroid Presenting as a Superior Mediastinal Mass

“…As for the presence of orthotopic thyroid glands, no eutopic thyroids were observed in 70%-75% of lingual thyroids, and in addition, most of the lingual thyroid cases were hypothyroidism [5,11,12]. In reports of mediastinal ectopic thyroids, they seemed to have orthotopic thyroid and euthyroid function in most of the cases [5,7,8,[13][14][15][16][17][18]. However, Santangelo et al reported five cases of ectopic thyroids in the mediastinum.…”

Mediastinal ectopic thyroid gland

“…The thyroid completes its descent in the seventh gestational week. Presence of ectopic thyroid tissues in distant locations could happen as a result of abnormal migration or heterotopic differentiation of uncommitted endodermal cells 4…”