P2809 - Metastatic Renal Cell Carcinoma Masquerading as Primary Gastric Cancer - A Rare Case Report

Kuntal Bhowmick, MD¹, Samantha Gage, MD², Jason Ferreira, MD^3
1Warren Alpert Medical School of Brown University, Providence, RI; ²Warren Alpert Medical School of Brown University, Johnston, RI; ³University Gastroenterology, LLC, Providence, RI

Introduction: Metastatic cancer to the stomach is uncommon, comprising less than 1% of gastric malignancies. These metastatic tumors are commonly breast, lung, or esophageal in origin. Renal cell carcinoma (RCC) very rarely spreads to the stomach, representing 0.2% of RCC cases, but may be associated with significant morbidity given its potential hypervascularity. We herein report a case of metastatic RCC presenting as an upper gastrointestinal bleed, found to have spread to the stomach and pancreas.

Case Description/Methods: A 65 year old male with a history of RCC status-post nephrectomy 9 years prior presented to the emergency department with melena, dyspnea, and weakness. He was found to be profoundly anemic with a hemoglobin of 4.6 g/dL and was subsequently stabilized with multiple blood transfusions. An esophagogastroduodenoscopy revealed a 2 cm non-obstructing, cratered gastric ulcer with heaped up margins (figure 1). A biopsy at that time was suggestive of a poorly differentiated adenocarcinoma. A staging CT further revealed multiple pancreatic masses, concerning for metastatic disease from a gastric primary. Following this hospitalization, the patient underwent endoscopic ultrasound for fine needle biopsy (FNB) of a pancreatic mass. The gastric mass was also staged as T2N0 by endosonographic criteria and a repeat biopsy was taken. However, this biopsy result was positive for PAX-8, consistent with metastatic RCC to the stomach. The FNB sample would also return with RCC, leading to a unifying diagnosis of stage IV RCC.

Discussion: Metastatic RCC lesions to the stomach tend to be slow growing and can be found up to 23 years after treatment of the index tumor. A helpful marker for determining renal origin is PAX-8, a transcription factor abundantly expressed in renal tissue, but typically absent in the gastrointestinal tract. This patient also had involvement of the pancreas by RCC, which is relatively more common and would portend a more favorable prognosis when found in isolation. Though exceedingly rare, this case demonstrates that metastatic RCC should be considered in any patient with a history of RCC presenting with a new gastric mass.



Disclosures:


Kuntal Bhowmick, MD¹, Samantha Gage, MD², Jason Ferreira, MD³. P2809 - Metastatic Renal Cell Carcinoma Masquerading as Primary Gastric Cancer - A Rare Case Report, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.