Introduction: Metastatic disease of the small bowel is very rare. Tumors, most commonly known to metastasize to small bowel include melanoma, lung cancer, cervical carcinoma and renal cell carcinoma (RCC). Although, RCC has a strong potential for hematogenous spread, gastroduodenal metastasis from RCC is extremely rare and only a few cases have been reported in literature. Herein, we describe an unusual case of metastatic RCC presenting as duodenal and gastric polyps.
Case: A 80 year old female with history of stage 1 clear cell RCC (T1b), s/p nephrectomy 5 years ago, currently on pazopanib, presented with dizziness and fall. She was found to be severely anemic with a positive stool guaiac at presentation. Esophagogastroduodenoscopy was performed, which revealed multiple ulcerated erythematous polyps (4-10 mm size) in gastric antrum, fundus and duodenum. Biopsies were obtained and histopathology and Immunohistochemical results confirmed renal epithelial origin of the cells. Further imaging revealed pulmonary and lymph node metastases. Patient subsequently developed left eye proptosis with progressive blurring of vision and was found to have a large intraconal mass. Debulking surgery was performed and pathology results were consistent with metastatic RCC. Patient was started on palliative radiotherapy and chemotherapy with sunitinib.
Discussion: RCC accounts for 3% of all adult malignancies with clear cell RCC is the most common histological subtype. RCC is known for its ubiquitous pattern of metastasis and most common sites of metastasis are the lungs, bones, liver and brain. Gastroduodenal metastasis from RCC is very rare and can be involved by direct invasion of the tumor or through lymphatic or hematogenous spread. The main presenting features are upper gastrointestinal bleeding (69%), obstructive symptoms and anemia. Endoscopically, the lesions can be seen as a polypoid mass or submucosal tumor with ulceration, usually involving the periampullary region or duodenal bulb. Several treatments have been reported in literature, including Whipple procedure, segmental resection, embolization and palliative treatment depending upon the extent of disease and metastasis. Unfavorable prognostic factors include, development of early metastasis after nephrectomy and widespread metastasis.