RCC accounts for 3% of adult malignancies. It arises from the proximal tubular epithelium of the kidney and has male preponderance (M:F 2:1). Mean age at presentation is 50–70 years. Both sporadic and hereditary forms exist which are associated with genetic abnormalities on the short arm of chromosome 3 (3p). In the United Kingdom the incidence has increased by 22% over 10 years while in the United States there has been an increase of 50% in 30 years . Deaths worldwide from kidney cancer exceed 100,000 per year .
Multiple risk factors include increased age, smoking, obesity, long-term dialysis, exposure to asbestos, petroleum products and cadmium, and several genetic syndromes including familial clear cell carcinoma, von Hippel-Lindau syndrome, and tuberous sclerosis .
Spread in RCC is lymphatic, haematogenous, transcoelomic, or by direct invasion. The most common sites of metastasis in RCC are the lung (75%) and lymph nodes (36%) followed by the bones (20%) and liver (18%) . Pancreatic metastasis is estimated at 1.3–1.9% of autopsy series; only 50% of pancreatic metastases are symptomatic, by 1996 only 66 cases of pancreatic metastasis in RCC had been reported [10, 11]. Solitary metastasis in RCC occurs in less than 5% of patients .
Autopsy series suggest only 2% of all tumours metastasise to the small intestine – RCC make up 7.1% of these lesions . A series published by Graham  stated only 4% of RCC metastasize to the small intestine, while a more recent Mayo Clinic 50-year review found only 3 cases of small intestinal metastasis in RCC, which did not include cases of direct tumour extension .
Of all intestinal segments involved RCC metastasis to the duodenum occurs least frequently . The overwhelming majority of tumours metastasising to the duodenum arise from the right kidney given its anatomic proximity , and of the few published reports most commonly involve the periampullary region, followed by the duodenal bulb. These usually manifest as gastrointestinal bleeding, although cases of small bowel intussusception are described [16–19]. Direct invasion of the duodenum from pancreatic metastases is also reported [13, 20–22].
Gastrointestinal bleeding as the presenting symptom of a primary renal cell carcinoma is described rarely in the literature [23, 24]. Bleeding is more commonly encountered in patients already known to have metastatic disease, or as the first symptom of metastatic disease in patients who have previously undergone nephrectomy for RCC [7, 25, 26].
Here we present a rare case of RCC whose primary manifestation of disease was with symptoms of upper gastrointestinal bleeding related to pancreatic metastases invading the duodenum. The source of bleeding in this case was obscure and initially missed by conventional gastroscopy – earlier diagnosis may have been facilitated using a side-viewing endoscope as described previously in a case of RCC metastasizing to the duodenal ampulla . Bleeding in our patient was managed radiologically and without complication, by selective trans-catheter embolisation of the anterior and posterior pancreaticoduodenal arteries. Arterial embolisation to control bleeding from duodenal metastasis from RCC has been previously reported to be successful [28, 29].
We also outline a case presenting 9 years after nephrectomy for RCC with isolated pancreatic and duodenal metastases causing intestinal bleeding. This is unusual as a recent study suggests the majority (83%) of tumours recur within 2 years of curative surgery, with higher recurrence rates in tumours of increasing size . However, cases of late recurrence presenting as GI bleeding have been reported at 19 years after nephrectomy for RCC . The longest documented survival from nephrectomy to the diagnosis of pancreatic metastasis is 27 years, and a more prolonged interval from nephrectomy to diagnosis seems to confer a better prognosis , presumably as a result of less aggressive tumour biology. Interestingly, in both patients described in our paper, RCC originated in the left kidney.
Palliative nephrectomy may alleviate local symptoms and can be undertaken in selected cases, but should be weighed against the burden of surgical morbidity and mortality, and is not justifiable for inducing disease regression which occurs in < 1% of patients . Outcome in metastatic RCC is generally poor, with 48% 1-year and 9% 5-year survival rates. Although evidence for the role of metastasectomy in RCC is lacking , surgery (by duodenopancreatectomy or total pancreatectomy) should be strongly considered in especially patients with isolated pancreatic metastases where it may provide 5-year survival rates of 31–68% [33, 34].