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

FDG-Avid Metastatic Non-Clear Cell Renal Cell Carcinoma Presenting as Intussusception

ABSTRACT

A 47-year-old man with a history of metastatic non-clear cell left renal cell carcinoma, unclassified subtype, status post left radical nephrectomy 4 years prior, and treated with immunotherapy for approximately 2½ years, presented for 18F-FDG PET/CT exam 7 months after immunotherapy was stopped. A contrast-enhanced CT exam performed 3 weeks prior demonstrated a new small bowel intussusception in the left upper quadrant. The PET/CT demonstrated focal FDG uptake in the segment of small bowel involved in the intussusception. Pathology from small bowel resection demonstrated metastatic renal cell carcinoma.

Small bowel intussusception - aetiology & management

PURPOSE OF REVIEW

Adult small bowel intussusception (SBI) differs in incidence, symptomatology and management from the more commonly encountered paediatric intussusception. This review spans across the multitude of causes of adult SBI, and summarises the diagnostic work-up and management options according to recent literature.

RECENT FINDINGS

There has been an increase in use of small bowel capsule endoscopy and point-of-care ultrasound for the diagnosis of acute adult SBI.

SUMMARY

A high degree of suspicion of a malignant cause of SBI is required in the adult population. Alarm clinical features include weight loss, history of malignancy, and iron deficiency anaemia. CT remains the gold standard imaging technique as it may identify the lead point and thus aid in endoscopic or surgical management. If malignancy is excluded and no lead point is identified, serology and histology may be helpful to look for inflammatory, infective and autoimmune aetiology.

Renal Cell Carcinoma Metastasis to the Small Bowel: A Rare Finding 10 Years After Nephrectomy

Renal cell carcinoma (RCC) most commonly metastasizes to the lung, lymph nodes, bone, and liver. RCC metastasizing to the small bowel is exceedingly rare (0.7%), and the ileum is the least likely site. We discuss the case of a 63-year-old male patient who presented with melena and a 10-kg unintentional weight loss in the preceding month 10 years after undergoing curative nephrectomy for RCC; he was found to have an ileal mass on CT imaging. He subsequently underwent a diagnostic gastroscopy and laparoscopy, later converted to a laparotomy, with bowel resection and anastomosis. The immunohistochemistry was consistent with RCC. This case report highlights the need for awareness about this rare but potential site of metastasis, which may present with gastrointestinal bleeding.