An Overlooked Cause of Severe Gastritis

Question: A 31-year-old man was admitted to our department with a complaint of epigastric pain and vomiting for 2 months. Esophago-gastroduodenoscopy performed in another hospital showed diffuse swollen gastric mucosa. These symptoms and swollen stomach were not relieved by long-term proton pump inhibitor treatment. He did not suffer from hematemesis, hematochezia, diarrhea, or fever. He was diagnosed with osteosarcoma in the left elbow joint 12 years before admission, for which he had received surgery and chemotherapy for 2 courses after the surgery. Unfortunately, the osteosacroma recurred in his left elbow joint 2 years before this admission, and another surgery was conducted. After the second surgery, another 2 courses of chemotherapy were given, followed by tislelizumab prescribed at an interval of 3 weeks until 2 months before admission. He did not have a past history of hypertension or diabetes mellitus, and he denied any consumption of non-steroidal anti-inflammatory drugs (NSAIDs), alcohol, or narcotics.