Case report and literature review: Small bowel intussusception due to solitary metachronous metastasis from renal cell carcinoma.

Introduction: Solitary metachronous small bowel metastasis from renal cell carcinoma (RCC) is rare. In contrast to idiopathic intussusception frequently occurring in children, adult intussusception is fairly uncommon and usually indicates a malignancy.

Case Presentation: We presented an 84-year-old man with small bowel intussusception and obstruction due to a solitary metachronous metastasis from RCC. Computed tomography with intravenous contrast revealed small bowel obstruction and a 4 × 4 cm intraluminal soft-tissue mass with moderate enhancement. During urgent exploratory laparotomy, a pedunculated tumor of the distal ileum was found to be the lead point of intussusception. Hence, reduction of the intestinal invagination and segmental resection of the ileum with functional end-to-end anastomosis were performed. Histological examination finally confirmed the diagnosis. The postoperative recovery was uneventful. The patient was discharged without any complications on postoperative day 6.

Conclusion: The case report highlights the rarity of solitary metachronous small bowel metastases from RCC and suggests that life-long follow-up of RCC patients is critical due to its unpredictable behavior and the possibility of a long period of dormancy. Complete surgical resection remains the mainstay treatment for such patients.