A Rare Cause of Gastrointestinal Bleeding: Metastatic Renal Cell Carcinoma

Abstract

This is a case of metastatic renal cell carcinoma to the small bowel as a cause of GI bleed. A 60-year-old man with known renal cell carcinoma metastatic to the lung s/p right nephrectomy, was admitted with anemia. He reported fatigue and melena for one week. He denied hematemesis, hematochezia, hematuria, epigastric pain, reflux symptoms, and did not use NSAIDs. Physical exam was notable for normal vital signs, conjunctival pallor, a soft non-tender abdomen, and rectal exam was negative for melena. Labs were significant for hemoglobin 6.8 (baseline 10), MCV 101, normal BUN, baseline creatinine 1.6. Upper endoscopy revealed a large ulcerated mass in the first portion of the duodenum with stigmata of recent bleeding. There were no additional abnormalities or sources for bleeding found during the procedure. Pathology from the mass confirmed metastatic renal cell carcinoma. The patient had a good response to blood transfusion and was discharged in stable condition. He underwent systemic therapy with ipilimumab and nivolumab. Hemoglobin remained stable without further GI bleeding. While malignancy is an uncommon cause of gastrointestinal bleeding (GIB) in the general population, it is the most common cause of GIB in oncologic patients (5% vs 23%). Patients with primary GI malignancies comprise a large proportion of those with tumor related bleeding. In contrast, those with malignancy outside of the GI tract are most likely to bleed from causes similar to that of the general population. In a retrospective study of 147 oncologic patients with an identified source of GIB, common sources of GIB in those with malignancies outside of the GI tract included ulcers, erosive disease, and varices. Only 10.9% percent of this group had malignancy related bleeding. A more recent study describing the epidemiology of GIB due to malignancy found that of the 71 GI bleeds due to tumors, only 5 cases (7%) were due to metastatic disease. Renal cell carcinoma is metastatic in 25-30% of patients at the time of diagnosis with common sites including the lung, liver, bone and brain. Metastatic disease to the small bowel is exceedingly rare, with only a few cases reported in the literature. Presenting symptoms are variable and can include abdominal pain, intussusception, obstruction, and GI bleed. Metastasis to the duodenum is thought to arise from primary tumors of the right kidney given the close proximity, as in our patient who underwent right nephrectomy.Figure: duodenal mass.Figure: duodenal mass.Figure: duodenal mass.