Metastatic renal cell carcinoma presenting as gastric polyps: A case report and review of the literature.

INTRODUCTION: Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and is responsible for over 13,000 deaths in the U.S. annually. The fatalities are largely due to distant metastasis, with lung, liver, bone and brain being most commonly affected organs. Gastric metastasis from RCC is a rare event (less than 20 cases reported in the English language literature) and usually presents as a large, solitary mass or ulcer (average size of 4.8cm) resembling primary gastric cancer. Here we report the first case of metastatic RCC presenting as small gastric polyps. PRESENTATION OF CASE: The patient was a 60-year-old African American woman with a history of clear cell RCC (pT1bNX). She underwent esophagogastroduodenoscopy and colonoscopy 5months after nephrectomy due to anemia. Two non-ulcerated, 0.6-cm benign-appearing polyps were found at the greater curvature of the gastric body, which were subsequently removed endoscopically. Unexpectedly, histopathologic examination of the gastric polyps revealed nested collections of vacuolated epithelioid cells in a background of delicate, arborizing vasculature, immediately beneath the congested and hyperplastic foveolar epithelium. A diagnosis of metastatic RCC was rendered after confirming the renal epithelial origin by immunohistochemical stains. DISCUSSION: Gastric metastasis from RCC usually presents as a large, solitary mass or ulcer, but it can be subtle and present as multiple, small benign-appearing polyps.
CONCLUSION: A careful follow up and thorough endoscopic and histopathologic examinations should be conducted in patients with a history of RCC who present with gastrointestinal manifestations.