case_images: PMC10206281_01
case_images: Computed tomography (CT) showed multiple enlarged lymphatic in the supraclavicular or infraclavicular fossa (A) and uneven enhancement and thickening in the gastric body fundus (B). The positron emission tomography (PET)-CT scan (C, D) revealed all lesions were metabolically active.
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case_images: Contrast-enhanced computed tomography (CT) ( Figure 1A ) of the thorax and abdomen showed uneven enhancement and thickening and soft tissue mass in the gastric body fundus, with carcinoembryonic antigen (CEA) serum level of 3.5 ng/mL and glycoantigen (CA724) serum level of 11.4 KU/L. Additionally, multiple enlarged lymphatic shadows observed in the supraclavicular or infraclavicular fossa were recognized as supraclavicular lymph node metastasis ( Figure 1B ), which was proved by subsequent pathological examination. Simultaneously, positron emission tomography (PET)-CT revealed uneven thickening and formation of masses in the gastric wall of the cardia-fundus-gastric body, and multiple enlarged lymph nodes on the side of lesser gastric curvature, retroperitoneum, parietal abdominal aorta, and left supraclavicular and infraclavicular fossa ( Figures 1C, D ), all of which were metabolically active. September 6, 2022, the patient was treated with intravenous capecitabine (1000 mg twice a day on days 1-14) plus oxaliplatin (130 mg/m2 once on day 1) (XELOX) in combination with tislelizumab (200 mg once on day 1) as first-line chemotherapy for eight cycles (3 weeks per cycle) due to her supraclavicular lymph node metastasis and her satisfactory ECOG PS score, PD-L1 expression, and TMB score. Subsequently, a contrast-enhanced CT scan demonstrated normalization of the previously unevenly thickened gastric wall ( Figure 1 ).
case_images: Preoperative contrast-enhanced computed tomography (CT) showed that the uneven thickening of the gastric wall and multiple enlarged lymphatic in the left cervical was reduced (A, B). The positron emission tomography (PET)-CT showed that the previously uneven thickening of gastric wall and the previously metabolically active lymph nodes in the left clavicular region was reduced, and metabolism dropped to the background (C, D). Gastroscopy after treatment revealed an ulcerated mass (E). The primary focus of stomach (F).
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case_images: Preoperative contrast-enhanced CT of the thorax and abdomen ( Figures 2A, B ) showed that the uneven thickening of the gastric wall in the fundus and body of the stomach was reduced, and the multiple enlarged lymph nodes on the side of the lesser gastric curvature, retroperitoneum, parietal abdominal aorta, and left supraclavicular and infraclavicular fossa were reduced and shrunk. Similarly, compared to the PET/CT on February 08, 2022, preoperative PET/CT ( Figures 2C, D ) revealed a dramatic reduction in the previously uneven thickening of the gastric wall in the cardia-fundus-gastric body, a reduction in the size of the previously metabolically active lymph nodes in the left clavicular region, abdominal cavity, retroperitoneum, bilateral parietal iliac vessels, and anterior iliac, and a decline in metabolism to the background, which was considered as a post-treatment change. Gastroscopy revealed an ulcerated mass in the fundus and the lesser curvature of the stomach, with lesions involving the cardia, gastric horn, and part of the gastric sinus ( Figure 2E ). The primary focus of the stomach is shown in  Figure 2F .
case_images: The gastric tissue sent for examination showed ulcerative changes, and no tumor cells remained (A, B). No residual tumor cells were seen in the lymph nodes sent for examination (C).
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case_images: The pathological results showed ( Figures 3A-C ) : 1. the gastric tissue sent for examination showed ulcerative changes, no cancer cell residue was seen;
case_images: Clinical course over time. It includes the treatments, diagnostic procedures and timing of disease progression.
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case_images: The timeline is displayed in  Figure 4 .