PMC6861174_01
Longitudinal gray-scale (A) and color Doppler (B) sonograms show a predominantly solid thyroid nodule (arrows, 5.5 cm in the largest diameter) in the right lobe. This nodule exhibits benign sonographic features such as isoechogenicity, smooth margins, a hypoechoic halo, oval shape, and peripheral vascularity. Based on histopathological analysis after the right lobectomy, the right thyroid nodule was diagnosed as follicular adenoma.
fendo-10-00783-g0001.jpg
PMC6861174_01_fendo-10-00783-g0001.jpg
F1
Thyroid US showed a predominantly solid thyroid nodule with benign US features in the right lobe (Figures 1A,B).
Chest computed tomography (lung window) (A) show multiple, variable-sized nodules in both the lungs. Computed tomography-guided transthoracic core needle biopsy was performed for the lung nodule in the right upper lobe. The biopsied lung mass was composed of cells with an irregular follicular pattern (hematoxylin and eosin stain, x100) (B). The follicular cells show nuclear enlargement, irregularity, and grooves (hematoxylin and eosin stain, x400), which were positive for thyroglobulin, thyroid transcription factor-1, and HBME-1 immunohistochemical stain (inset) (C).
fendo-10-00783-g0002.jpg
PMC6861174_01_fendo-10-00783-g0002.jpg
F2
A subsequent chest X-ray and computed tomography (CT) showed multiple lung nodules in both lungs (Figure 2A). The biopsied lung mass revealed follicular patterned tumor cells which were positive for thyroglobulin, thyroid transcription factor-1, and HBME-1 (Figures 2B,C), and histopathological analysis confirmed lung metastasis from thyroid malignancy.
Multiple metastatic nodules in both the lungs exhibited interval increase in size and number on follow-up chest CT (A). On the same day, the patient underwent neck CT, and a newly developed heterogeneous enhancing mass (arrows) was detected in the right parietal lobe (B). In the re-evaluation of a previous right lobectomy specimen, the right thyroid mass was entirely composed of small- and large-sized follicles and diffusely presented with papillary-like nuclear features (hematoxylin and eosin stain, x400), which were positive for HBME-1 immunohistochemical staining (inset) (C). A focus of discrete vascular invasion with endothelium covered tumor cells adherent to the vessel wall (hematoxylin and eosin stain, x200) is identified (D).
fendo-10-00783-g0003.jpg
PMC6861174_01_fendo-10-00783-g0003.jpg
F3
In March 2018, follow-up chest X-ray and CT were performed (Figure 3A), and multiple metastatic lung nodules exhibited interval increase in size and number. Although a right parietal lobe mass was incidentally identified in the neck CT (Figure 3B), a biopsy trial for the right parietal lobe mass was not performed. A focus of vascular invasion with endothelium covered tumor cells adherent to the vessel wall was also identified on serial section of thyroid tumor (Figures 3C,D).