2683 Gastric Metastasis From Renal Cell Carcinoma: A Case Report

Abstract

INTRODUCTION: Renal cell carcinoma (RCC) is the most common renal malignancy in adults and possesses extensive metastatic potential. At the time of diagnosis, over 30% of cases have metastatic lesions and a 10% risk of developing metastatic disease after 5 years. The most commonly involved sites for metastasis include regional lymph nodes and distant organs such as the lungs, liver, and brain. In very rare cases, it can spread to gastrointestinal tract. CASE DESCRIPTION/METHODS: The patient is a 74 year old male found to have a 5 cm right kidney mass while undergoing workup for uncontrolled HTN. Histology and workup after radical resection confirmed clear cell carcinoma limited to the right kidney. Follow up CT a year after diagnosis revealed bilateral adrenal gland nodules. Biopsy of which was consistent with metastatic renal cell carcinoma at which point chemotherapy was started. Restaging two years thereafter and multiple follow up surveillance CT scans revealed no evidence of disease progression. Nine years after the original diagnosis, patient was admitted for hypotension and anemia. EGD done in evaluation of anemia, revealed multiple gastric submucosal polyps, biopsy of which revealed metastatic renal cell carcinoma. Immunostaining with PAX-8 and renal tumor markers were positive further proving RCC as the primary carcinoma. At this point the patient was restarted on chemotherapy and discharged with close follow up. DISCUSSION: Within the gastrointestinal tract, metastasis of RCC to the stomach is the rarest, at a rate of <0.2%. The process by which tumor cells migrate from the primary site to distant organs and the predilection to metastasize to specific organ systems is not well understood. In the rare instance that RCC metastasizes to the stomach, it most frequently presents as a polypoid submucosal protruding mass leading to gastrointestinal bleeding and symptomatic to anemia . The optimal treatment for RCC remains controversial and the utility of resection on mortality remains unclear. In our patient, the period from radical resection to detection of metastatic gastric lesions was over nine years. At the time of resection, the lesion was confined to the left kidney only as per staging imaging obtained. This raises many questions: how can metastatic lesions present after the resection of a tumor with no invasion of the kidney capsule? How can these new lesions appear almost a decade later? And finally, how effective is resection of primary RCC tumor in regards to preventing metastasis?