case_images: PMC7238324_01
case_images: Images taken during the initial visit. Computed tomography revealed a large right-upper mediastinal tumor (a) and micropulmonary metastases (b).
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case_images: PMC7238324_01_CRIE2020-6438352.001.jpg
case_images: fig1
case_images: Computed tomography (CT) revealed a large right-upper mediastinal tumor and micropulmonary metastases (Figures 1(a) and 1(b)).
case_images: Images taken at baseline and 14 weeks after lenvatinib treatment. The tumor shrank upon treatment, and the major axis was reduced in diameter from 68 to 48 mm. The tumor embolus regressed from the junction of the superior vena cava.
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case_images: PMC7238324_01_CRIE2020-6438352.002.jpg
case_images: fig2
case_images: Because the tumor obstructed the right brachiocephalic vein and approached the superior vena cava (SVC) junction, there was a risk of SVC occlusion and pulmonary embolism (Figure 2(a)). The tumor embolus regressed from the junction of the SVC, permitting the right brachiocephalic vein to be clamped and ligated safely (Figure 2(b)).
case_images: Surgical procedure and after surgery image ((a) and (b)). The sternum was incised as shown in the figure; the sternoclavicular joint and collarbone were flipped outward, and surgery was performed.
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case_images: PMC7238324_01_CRIE2020-6438352.003.jpg
case_images: fig3
case_images: The risk of SVC syndrome and pulmonary embolism was resolved, and the tumor was largely resected.  Figure 3 shows the schema of the surgical procedure and CT after the operation.
case_images: Histologic sections of resected tumor ((a) and (b)). (a) Histopathological image of the central part of the papillary carcinoma tumor. The tumor formed a papillary structure. Individual cancer cells had nuclear grooves, and findings suggestive of nuclear inclusions were also observed. Original magnification 100x. (b) Histopathological image of the periphery of the tumor. Extensive necrosis and fibrosis caused by lenvatinib were observed. Original magnification 100x.
case_images: CRIE2020-6438352.004.jpg
case_images: PMC7238324_01_CRIE2020-6438352.004.jpg
case_images: fig4
case_images: No primary lesion remained in the thyroid gland, and the lenvatinib had a beneficial effect on papillary carcinoma originating from the upper mediastinum.  Figure 4(a) presents a histopathological image of the central region of the papillary carcinoma lesion.  Figure 4(b) presents a histopathological image of the periphery of the tumor.