SHM Converge Scientific Abstract ePoster Gallery-Not So Clear: An Unusual Metastasis of Renal Cell Carcinoma

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This case report describes an unusual late metastasis of clear cell renal cell carcinoma (ccRCC) to the stomach. Gastric spread from RCC is extremely rare, occurring in about 0.2% of cases, and is usually found years after the original kidney tumor.<br /><br />The patient was an 84-year-old man with a history of ccRCC treated by left radical nephrectomy at age 61. He later developed a solitary lung metastasis that was surgically removed without systemic therapy. During workup of an unrelated abdominal aortic aneurysm, CT imaging revealed a 16 mm enhancing pancreatic head mass. Additional studies, including MRCP, PSMA PET/CT, EGD, and EUS, were performed to evaluate the lesion and exclude other malignancies. The pancreatic lesion biopsy was nondiagnostic, but a small erythematous lesion in the gastric antrum was biopsied and unexpectedly showed metastatic ccRCC.<br /><br />The report emphasizes that gastrointestinal metastases from ccRCC are often difficult to detect with imaging alone, especially when lesions are small and solitary. Patients are frequently symptomatic with anemia, abdominal pain, vomiting, or anorexia, but this patient’s gastric lesion was found incidentally. Endoscopically, gastric metastases from RCC are usually polypoid or submucosal, making this erythematous mucosal lesion an unusual appearance.<br /><br />Pathology can also be challenging because ccRCC may resemble other clear-cell tumors. Immunohistochemical staining, such as PAX8 and CD10, helps confirm renal origin and distinguish it from mimics like signet ring gastric carcinoma, histiocytic lesions, or breast cancer.<br /><br />The authors conclude that, as survival improves in ccRCC, clinicians should maintain awareness of rare metastatic sites, including the stomach, even decades after nephrectomy.

Asset Subtitle

Rachel L. Dennis

Meta Tag

Author List Alexander Doubt, Allison Bush, Anthony Marchand, John Mattingly, Nieka Harris, Rachel L. Dennis

Category Clinical Vignettes

Concept Clear Cell Renal Cell Carcinoma

Concept Gastrointestinal Metastasis

Concept Mucosal Lesion

Concept Computed Tomography

Concept Upper Endoscopy

Distinguished Non-Finalist

Presenter Organization Naval Medical Center Portsmouth

Presenting Author Rachel L. Dennis

Track Adult

Keywords

clear cell renal cell carcinoma

gastric metastasis

late metastasis

rare metastasis

nephrectomy

endoscopy

immunohistochemistry

PAX8

CD10

stomach

Clear Cell Renal Cell Carcinoma

Gastrointestinal Metastasis

Mucosal Lesion

Computed Tomography

Upper Endoscopy