All images show massive free air (white arrowheads and G), and there is ascites (reference mark) in the Morison pouch in Fig.13-Fig.15. As for the large lesion (T) of liver of Fig.2-Fig.12, irregular internal structure is highly suggestive of metastatic tumor. Black arrows of Fig.4-Fig.11 indicates a deep ulcerative lesion, and mucosa of stomach (black arrowheads) of Fig.5-Fig.10 is slightly thickened and strongly contrast-enhanced comparing with the other part, suggesting a neoplastic lesion. White arrows of Fig.5-Fig.10 are very likely to be enlarged lymph nodes. Therefore, perforated gastric cancer with metastases to liver is a diagnosis. Circled number 12: duodenum. Perforation of gastric cancer (Fig.A: black arrows) with liver and lymph node metastasis was confirmed by surgery and pathology.

Reference case 1 (5mm slice, gastric cancer perforation): A 70-year-old female. She had occasional epigastric pain for a few days, which suddenly increased in intensity nine hours ago. Temperature: 37.5 degrees Celsius, physical examination revealed tenderness and rebound tenderness in epigastrium, but without muscle guarding.
Free air (G) of Fig.1-Fig.4 and ascites (reference mark) of Fig.9-Fig.16 strongly indicate gastrointestinal perforation. The hepatic lesion (white arrows) of Fig.1 and Fig.2, and enlarged lymph nodes (white arrowhead) of Fig.1-Fig.5 suggest metastasis of malignant tumor. Black arrowheads of Fig.8-Fig.14 show wall thickening with irregular contrast enhancement indicating gastric cancer, and black arrow of Fig.8-Fig.10 is an ulcer leading to a diagnosis as perforation of gastric cancer. Surgery revealed a perforated firm tumor of 5cm size in anterior wall of stomach and several metastatic nodes in lesser curvature side as well as liver metastasis. Pathology reported as gastric cancer.

Reference case 2(gastric cancer): A 54-year-old female with epigastric pain for 24 hours.
Black arrow of CT images, black arrowheads of endoscopy and white arrowheads of resected specimen show gastric cancer. Pathology: adenocarcinoma.