Snapshot A 56-year-old man presents to his primary care physician for abdominal pain. His abdominal pain is in the epigastrium and has been persistent. He has had episodes of night sweats and has unintentionally lost 20 pounds over the course of 3 months. He has a past medical history of H. pylori infection and obesity. Physical examination is notable for epigastric abdominal tenderness upon palpation. An upper endoscopy demonstrates an invasive ulcerative lesion in the stomach. Introduction Overview gastric adenocarcinoma is the most common type of gastric cancer, accounting for more than 90% of cases other gastric cancer types include lymphoma, stromal, and carcinoid tumor gastric adenocarcinoma can be divided into intestinal and diffuse types intestinal bulky tumors that have glandular structures (similar to adenocarcinoma of the esophagus and colon) the mass can be exophytic or ulcerated commonly found on the lesser curvature of the stomach diffuse infiltrative tumors composed of signet ring cells (mucin vacuoles that push the nucleus to the periphery) stiffens the gastric wall, leading to a thickened, leather-like appearance (linitis plastica) Epidemiology incidence varies significantly in the world most common in Japan, Chile, and eastern Europe risk factors Helicobacter pylori Epstein-Barr virus nitrosamine exposure high salt intake smoking excessive alcohol use Pathophysiology H. pylori infection results in chronic gastritis secondary to increased production of proinflammator proteins Epstein-Barr virus a rare cause of gastric adenocarcinoma unclear how exactly this virus leads to gastric adenocarcinoma Presentation Symptoms persistent abdominal pain typically epigastric dysphagia in cases of gastric cancers arising more proximally in the stomach or in the esophagogastric junction Physical examination weight loss secondary to insuficcient caloric intake Imaging Endoscopy indication initial diagnostic study of choice to obtain a tissue diagnosis Barium studies indication although associated with a high false-negative rate, it may be superior to endoscopy in detecting linitis plastica Differential Gastric lymphoma differentiating factors secondary to B-cell lymphoproliferative disorders associated with mucosa-associated lymphoid tissue Gastric stromal cancer differentiating factors mesechymal in origin Neuroendocrine (carcinoid) tumor differentiating factors arise from neuroendocrine origin leads to release of vasoactive substances, resulting in cutaneous flushing, bronchospasm, colicky abdominal pain, and diarrhea as well as right-sided cardiac valvular fiborosis Treatment Treatment is dependent on the stage of the cancer may require resection, adjuvant chemotherapy, and radiation Surgical endoscopic resection indication for local tumors gastrectomy with lymphadenectomy indication for more extensive disease Complications Virchow node left supraclavicular node involvement secondary to metastasis Krukenberg tumor metastasis to the bilateral ovaries Sister Mary Joseph nodule periumbilical metastasis