Simultaneous multiple primary small bowel cancers in a patient with anemia

A 79-year-old male with severe anemia was referred to our hospital for a suspected tumor in the small intestine. Contrast computed tomography (CT) and positron emission tomography (PET)-CT showed a tumor lesion in the jejunum. Oral single-balloon enteroscopy and small bowel capsule endoscopy revealed a Type 2 lesion in the jejunum and a Type 0-IIc lesion in the third portion of the duodenum. Histopathological examination of biopsy specimens showed that both lesions were adenocarcinomas. Here, we report a very rare case of simultaneous multiple primary small bowel cancers in a patient without known risk factors such as inflammatory bowel disease or hereditary condition (e.g., familial adenomatous polyposis, Lynch syndrome, Peutz-Jeghers syndrome).