Double-balloon enteroscopy in the diagnosis of small bowel tumors: lessons from three cases

Small bowel lymphoma may present with diffuse mucosal abnormalities, strictures, or masses. These features may resemble inflammatory enteropathy or other intestinal tumors. When clinical, imaging, and histological findings are inconsistent, diagnosis can be a challenge. We report two cases of small bowel lymphoma and one gastrointestinal stromal tumor (GIST) initially suspected to be lymphoma. The first patient, a 67-year-old man, presented with severe diarrhea and was initially suspected of having a viral infection. Double-balloon enteroscopy (DBE) revealed extensive villous shortening or loss. Distal jejunal biopsies showed focal atypia, and proximal biopsies showed atypical lymphoid cells, confirming intestinal T-cell lymphoma. He died approximately six weeks after diagnosis despite CHOP-based chemotherapy. The second patient was a 46-year-old man with long-term intestinal lymphangiectasia who developed small bowel obstruction. DBE identified an ulcerated ileal stricture. Biopsies showed atypical lymphoid cells, but necrosis and crush artifact prevented definitive classification. Subsequent CT-guided biopsy of the mass established diffuse large B-cell lymphoma. He achieved a partial response to Pola-R-CHP, with sustained symptom relief over three months. The third patient was a 72-year-old man who presented with obstructed defecation and imaging findings suspicious for small bowel lymphoma. Endoscopic ultrasonography demonstrated an extrarectal mass. DBE identified small bowel stenosis, and biopsies revealed a spindle-cell tumor expressing CD117 and DOG1, supporting the diagnosis of GIST. He underwent resection followed by imatinib and reported no discomfort at approximately two years. DBE enables targeted tissue sampling, while definitive tumor classification relies on histopathological and immunohistochemical findings. When findings conflict, the lesion’s location and the adequacy of sampled tissue should be reassessed. If endoscopic histopathology remains inconclusive, further tissue acquisition is necessary.