Case Presentation: A 45-year-old Vietnamese female with history of H. pylori who presented with worsening nausea, vomiting, epigastric abdominal pain and early satiety. Patient reported her epigastric pain had been intermittent for the past six months but had acutely worsen in the last two weeks. There were no initial inciting events that triggered these symptoms. However, her symptoms of nausea, vomiting and abdominal pain were exacerbated with any food intake. The patient could no longer tolerate any oral intake which prompted her visit to the emergency room. Her physical exam revealed stable vital signs. Abdominal examination was significant for mild tenderness over the epigastric region. No organomegaly was noted. Bowel sounds were normal. Complete blood count and complete metabolic panel were normal. Computed tomography with contrast of the abdomen showed a distended stomach with mural wall thickening, as well as minimal ascites in the abdomen and pelvis. Initial attempt at paracentesis using POCUS was not successful due to low volume ascites. Interventional Radiology also declined paracentesis given risks outweigh benefits. The gastroenterology team performed an upper endoscopy, which showed a circumferential mass proximal to the pylorus, causing near obstruction with pinpoint opening. Biopsy of the mass showed poorly differentiated gastric adenocarcinoma with signet ring cells. EUS staging demonstrated a Stage IIB, T3N0M0 with 24 mm thick gastric tumor breaching the serosal layer. The patient underwent staging laparoscopy and jejunal tube placement. Intraoperatively, numerous peritoneal plaques, rare omental nodules, ascites, and mesenteric plaques were noted on the anterior abdominal wall, along the loops of small bowel, and on the hemidiaphragms bilaterally. Biopsies of the nodules and cytology of the ascites were consistent with metastatic Stage IV gastric adenocarcinoma with signet ring cells.

Discussion: Signet ring cell carcinoma is a significant subtype of gastric cancers, as the findings of signet ring cells on histology has traditionally been associated with poor prognosis. This may be because signet ring cell carcinomas are often advanced on presentation. Therefore, an accurate staging is necessary to provide the optimal therapeutic options for gastric cancer. Endoscopic ultrasonography is a valuable tool for local regional staging, and it is often used to assess for tumor and nodal involvement in the presurgical evaluation. However, its accuracy in T staging is about 60-90% and N staging remains 50-80% (1). Some parts of the stomach are especially difficult to cover with endoscopic ultrasound. Given the anatomy of the proximal stomach, it often leads to an oblique EUS scanning resulting in a misinterpretation of the true penetration (2).

Conclusions: This case illustrates the difficulty to accurately stage gastric cancer. Given normal complete metabolic panel and CT staging with contrast, what was initially thought to be a T3 tumor turned out to be metastatic disease. The incidence of gastric cancers is much higher in many areas of southeast Asia, including Vietnam where this patient is originally from. In addition, H. pylori infection is a well-established risk factor of various gastric cancers. Although there are no established guidelines for gastric cancer screening in the United States, it is commonly recommended in Asian countries like Japan and Korea. Perhaps routine endoscopy screening for this high-risk patient could have yielded an earlier diagnosis and better outcome.

IMAGE 1: EUS demonstrating 24mm thick gastric tumor breaching serosa

IMAGE 2: Near obstructing mass in antrum on EGD