case_images: PMC9938394_01
case_images: Chest computed tomography (CT) images throughout the course of the treatment. a, c Chest contrast-enhanced CT axial view following the drainage of the right pleural effusion before chemotherapy on day 11. A large mass is detected in the right thoracic cavity with contrast enhancement. Pleural effusion is found in the right-sided chest cavity and passive atelectasis in the right lung. b, d Chest CT axial view after 37 days of chemotherapy, showing a remarkable reduction of the tumor size and pleural effusion.
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case_images: F1
case_images: Contrast-enhanced computed tomography (CT) of the chest revealed a large mass in the right lung, which was complicated with hemorrhagic pleural effusion and passive atelectasis in the right lung (Fig. 1a, c). CT showed reduction in the tumor size and pleural effusion (Fig. 1b, d).
case_images: Levels of hemoglobin (Hb) (solid line) and serum C-reactive protein (CRP) (dashed line) throughout the treatment course. R with a circle denotes red blood cell transfusion, N with a circle denotes nivolumab administration (360 mg), and I with a circle denotes ipilimumab administration (1 mg/kg). Following admission, several red blood cell transfusions were required because of progressive anemia. However, owing to chemotherapy, anemia improved, and blood transfusions were no longer required. The CRP level also reduced with treatment.
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case_images: F2
case_images: Thoracoscopy was performed for diagnosis (Fig. 2), which revealed that the large tumor on the parietal pleura in the dorsal region of the right lung was fragile and bleeding. As the treatment progressed, the anemia of the patient improved and he did not require further blood transfusions (Fig. 2).
case_images: Histological results of the specimen obtained via thoracoscopy. The bars show 100 microm. a Photomicrograph of hematoxylin and eosin staining (x 200 magnification). Epithelioid cells with enlarged hyperchromatic nuclei and prominent nucleoli composed the sheets. The tumor contained vascular lumen-like structures with abundant red blood cells scattered. Immunohistochemistry results (x 400 magnification): (b) CD31, (c) calretinin, and (d) PD-L1. The tumor cells were positive for CD31, negative for calretinin, and diffusely positive for PD-L1.
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case_images: PMC9938394_01_cro-2023-0016-0001-529447_f3.jpg
case_images: F3
case_images: Vascular lumen-like structures, including abundant red blood cells, were scattered across the tumor (Fig. 3a). Immunohistochemistry demonstrated that the tumor cells were strongly positive for CD31, a vascular endothelial marker (Fig. 3b). Furthermore, the tumor cells were positive for pan-cytokeratin (CAM5.2) and negative for calretinin (Fig. 3c), thyroid transcription factor 1, carcinoembryonic antigen, and epithelial cell adhesion molecule. PPA. Programmed cell death-ligand 1 (PD-L1; clone 22C3) was diffusely positive in the tumor cells (Fig. 3d).