A case of small intestinal malignant lymphoma associated with intestinal obstruction: A case report

Small bowel obstruction (SBO) is a common surgical emergency, most frequently caused by postoperative adhesions. However, neoplastic etiologies, including malignant lymphoma, should also be considered in the differential diagnosis.

A 78-year-old Japanese man with a history of recurrent SBO since 2021 presented with nausea and abdominal distention. He had previously undergone conservative treatment on seven occasions. Contrast-enhanced computed tomography revealed small bowel dilatation with segmental wall thickening and enhanced contrast effect, along with enlarged mesenteric lymph nodes. He was diagnosed with SBO and admitted for emergency treatment. An ileus tube was inserted, and contrast study on day 3 revealed a stricture in the ileum, which the tube could not pass. Adhesive ileus and small intestinal tumor were both considered. As conservative treatment was ineffective, laparoscopic-assisted segmental ileal resection was performed. Histopathological examination revealed diffuse large B-cell lymphoma. Postoperative recovery was uneventful, and he was discharged on postoperative day 21. Positron emission tomography/computed tomography showed FDG uptake in mesenteric lymph nodes (SUVmax 3.7), consistent with Lugano stage II disease. Due to advanced age and dementia, the patient did not undergo chemotherapy. He remains under surgical follow-up without disease progression one year postoperatively.

This case highlights that repeated SBO may not always be caused by adhesions alone, and intestinal lymphoma should be considered, especially when imaging reveals suspicious findings.

In cases of recurrent SBO, small intestinal lymphoma should be included in the differential diagnosis, even in elderly patients with a history of abdominal surgery.