case_images: PMC10869506_01
case_images: Images were taken using objectives (A) at x20 magnification and (B) at x40 magnification. Tumor cells show obvious atypia, arranged in a sheet-like distribution with nests, and the abundant blood vessels are between the tumor nests. The tumor cells appear to have a clear cytoplasm with weak cytoplasmic staining and clear cell borders, showing a plant cell-like appearance, and they also contain an eosinophilic cytoplasm and irregular nuclear contours with a perinuclear halo, and rough chromatin and obvious nucleoli can be observed.
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case_images: The postoperative pathological report showed the following: tumor cells showing obvious atypia, which are arranged in a sheet-like distribution with nests; abundant blood vessels between the tumor nests; tumor cells that appear to have a clear cytoplasm with weak cytoplasmic staining and clear cell borders, showing a plant cell-like appearance; tumor cells containing an eosinophilic cytoplasm and irregular nuclear contours with perinuclear halo; and rough chromatin and obvious nucleoli ( Figure 1 ).
case_images: On 23 March 2018, CT showed metastatic lesions in the lungs 4 years post-surgery. Multiple nodular high-density shadows were observed in the lungs, and the largest one was approximately 0.2-0.9 cm in size.
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case_images: March 2018, a CT scan of the lungs demonstrated that multiple nodular high-density shadows approximately 0.2-0.9 cm in size were observed in the lungs, which were considered as metastatic malignant tumors ( Figure 2 ). Moreover, no malignancy was identified on the abdomen CT.
case_images: On 22 February 2021, CT and MRI showed new metastatic lesions in the bone after being treated with sunitinib monotherapy for 3 years in the cervical vertebra (A), thoracic vertebra (B), lumbar vertebra (C), and space-occupying lesion next to the left side of L5 (D).
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case_images: Figure 3 ). Furthermore, pulmonary CT showed multiple nodular high-density shadows in both lungs approximately 0.4-1.5 cm in size, and multiple lymph nodes were enlarged in the mediastinum and bilateral pulmonary hilum with the largest one being 1.5 cm in size ( Figure 4 ).
case_images: On 22 February 2021, CT showed the metastatic lesions enlarged in different lung lobes (A-C) after being treated with sunitinib monotherapy for 3 years. Multiple nodular highdensity shadows were observed in both lungs, and the largest was approximately 0.4-1.5 cm in size.
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case_images: Figure 3 ). Furthermore, pulmonary CT showed multiple nodular high-density shadows in both lungs approximately 0.4-1.5 cm in size, and multiple lymph nodes were enlarged in the mediastinum and bilateral pulmonary hilum with the largest one being 1.5 cm in size ( Figure 4 ).
case_images: On 25 October 2023, CT showed that metastatic lesions decreased in size in different lung lobes (A-C) (by comparing with corresponding parts in 
  Figure 4
  ) after being treated with sintilimab plus axitinib for over 2 years, and the largest one was approximately 0.2-0.7cm in size. No obvious enlargement of the lymph nodes in the mediastinum was observed.
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case_images: Meanwhile, no obvious enlargement of the lymph nodes in the mediastinum was observed, and bone metastases on the right 4th and 6th ribs were similar to the former ones ( Figure 5 ).
case_images: On 3 March 2023, MRI of the thoracic and lumbar vertebrae showed that metastatic lesions in the thoracic vertebra (A) and lumbar vertebra (B) bone remained stable after being treated with sintilimab plus axitinib for 2 years.
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case_images: Moreover, on 3 March 2023, MRI of the thoracic and lumbar vertebrae revealed that abnormal signals were roughly similar to the previous image ( Figure 6 ).