PMC5303849_01
A right paratracheal mass in the upper mediastinum on the images of CTA from a patient presented with cough and right chest pain. A 61-year-old female presented to emergency room with cough and right chest pain. Chest CTA was performed to exclude pulmonary embolism as part of chest pain workup. One 2.0 x 1.7 cm right paratracheal mediastinal mass was visualized on the images of CTA, as indicated by a blue arrow on coronal (a) and axial (b) view images of CTA. This right paratracheal mass appeared hyperdense or showed mild contrast enhancement relative to other small mediastinal lymph nodes.
CRIRA2017-9084207.001.jpg
PMC5303849_01_CRIRA2017-9084207.001.jpg
fig1
On the images of CTA, a 2.0 x 1.7 cm right paratracheal mediastinal mass was noted which appeared slightly hyperdense or showed mild contrast enhancement (Figure 1).
Histological image of ectopic thyroid tissue in mediastinum. Fragments of benign thyroid tissue identified in the cell block prepared from the transbronchial needle aspiration. Bland, uniform thyroid epithelial cells are disposed in the follicular units characteristic of benign thyroid tissue (blue arrow), with focal presence of intrafollicular colloid (red arrow). There is mild perifollicular hyalinization (Hematoxylin and Eosin, 20x).
CRIRA2017-9084207.002.jpg
PMC5303849_01_CRIRA2017-9084207.002.jpg
fig2
The patient underwent an endobronchial ultrasound-guided biopsy of the right paratracheal mass, which was found to be benign ectopic thyroid tissues by histological analysis of the biopsied tissue samples (Figure 2).
Functional and anatomic imaging of ectopic thyroid tissue in the upper mediastinum by I-123 SPECT/CT. A 2.0 x 1.7 cm right paratracheal mediastinal mass was visualized on the axial (a) and sagittal (c) view images of noncontrast enhanced low dose CT component of I-123 SPECT/CT as indicated by a blue arrow. On the axial (b) and sagittal (d) view images of coregistered I-123 SPECT/CT images, I-123 radioiodine uptake by the right paratracheal mass was visualized as indicated by orange color presentation of I-123 radioiodine activity. The findings of I-123 SPECT/CT further confirmed that the upper mediastinal mass seen on the CTA images represented functional ectopic thyroid tissue, consistent with the results of histological analysis of the tissue samples obtained by endobronchial ultrasound-guided biopsy.
CRIRA2017-9084207.003.jpg
PMC5303849_01_CRIRA2017-9084207.003.jpg
fig3
On SPECT/CT images, the focus of increased radioiodine uptake in the mediastinum seen on planar imaging was localized to the 2.0 x 1.7 cm right paratracheal mediastinal mass visualized on CTA (Figure 3).