A jejunal adenoma with high-grade dysplasia in the excluded limb 25 years after biliopancreatic diversion: A case report.

Biliopancreatic diversion (BPD) creates a biliopancreatic limb that is inaccessible to conventional endoscopic surveillance, and its long-term neoplastic risk is unknown. A woman in her late 40 s presented 25 years after BPD with recurrent protein malnutrition and subocclusive symptoms. Computed tomography showed jejunal intussusception. At surgery, the intussusception was localized to the proximal biliopancreatic limb, 10-20 cm from the ligament of Treitz and remote from the entero-enterostomy. A 2.6-cm tubulovillous adenoma with focal high-grade dysplasia was found at the corresponding site and was completely excised. This appears to be the first reported high-grade dysplastic adenoma in an excluded biliopancreatic limb after BPD. The finding shows that a conventional dysplastic adenoma can arise in this compartment and makes an adenoma-carcinoma pathway biologically plausible, but a single case cannot establish causality, incidence, or risk in other bariatric procedures. Routine imaging surveillance is not supported by current evidence. However, an intussusception remote from the entero-enterostomy, particularly when associated with recurrent obstructive symptoms, warrants evaluation for a structural lead point.