Clinicopathological features and differential diagnosis of gastric metastases

OBJECTIVE: Due to the rarity and non-specificity of symptoms, gastric metastases are often misdiagnosed, and patients are not treated promptly. The aim of this study was to study the clinicopathological features and differential diagnosis of gastric metastases. METHODS: From 2004 to 2021, 14 patients were diagnosed with gastric metastases not resulting from direct invasion (GMNDI) in our hospital, and their imaging and clinicopathological features were analyzed. RESULTS: PET-CT examination showed hypermetabolic nodules in the stomach. Under gastroscopy, GMNDI showed eminence, nodular or vegetable pattern mass, and ulcer. Microscopically, GMNDI showed similar pathological features and immunophenotypes to the primary tumor. In our study, the most common primary tumors were malignant melanoma (4 cases), small cell lung cancer (3 cases), and hepatocellular carcinoma (3 cases). Immunohistochemistry contributed to the pathological diagnosis and differential diagnosis of gastric metastases. Malignant melanoma expressed HMB45, MelanA, and S-100; small cell lung cancer expressed TTF-1, CD56, and CgA; hepatocellular carcinoma expressed GPC-3, hepatocyte, and Sall4. In a few cases, tumor cells may lose immune markers during metastasis. Therefore, it is necessary to combine medical history, imaging examination, and other clinical diagnosis methods in the pathological diagnosis. CONCLUSION: An in-depth understanding of GMNDI is conducive to better diagnosis and treatment planning for gastric metastases and subsequent improvement in patient prognosis.