RESUMEN
Malignant lymphomas of the duodenum and small intestine are relatively rare, but are clinically important, as they may result in perforation peritonitis. Here, we report a case of perforation peritonitis caused by multiple duodenal and small intestinal malignant lymphomas. An 84-year-old man was diagnosed with malignant lymphoma of the duodenum. Although chemotherapy was planned, emergency surgery was performed to treat perforation peritonitis. Laparoscopic observation revealed that the perforation was not in the duodenum, but in the ileum. In addition, numerous lymphoma lesions were revealed throughout the small intestine. Partial resection of the small intestine including the perforation was performed. Primary gastrointestinal malignant lymphoma may exist over multiple digestive tracts and it is necessary to carefully diagnose and treat, even in emergency surgery.