It is possible for stomach tumor to grow outside. When a patient suffers from gastric tumor without timely treatment, with the development of the disease, the tumor will gradually increase in size, thus invading into the plasma membrane layer, and even invading into the surrounding organs, blood vessels and lymphatic tissues, so gastric tumors may grow outside of the stomach. Gastric tumor is a common disease of digestive system, which can be divided into malignant and benign, malignant tumors include gastric cancer, malignant mesenchymal tumors and so on, while benign tumors include gastric adenoma, adenomatous polyps and so on. The common clinical symptoms include gastrointestinal bleeding, epigastric pain and so on. Gastric tumors are mainly treated by surgery, and some gastric malignant tumors can be treated by radiotherapy to improve patients’ symptoms and survival rate, and chemotherapy can also be used to slow down the development of the tumor and reduce the recurrence rate of the tumor. It is recommended that patients with gastric tumors should go to the hospital for regular checkups to find out whether the tumor has invaded the surrounding tissues or metastasized to distant places in time.