Asymptomatic Pancreatic Metastasis from Renal Cell Carcinoma Diagnosed 21 Years after Nephrectomy

This report presents our experience with a case of pancreatic metastasis of renal cell carcinoma (RCC) at a long-term follow-up after nephrectomy. A 73-year-old man underwent nephrectomy for right RCC 21 years ago; computed tomography (CT) scanning on routine follow-up revealed a solid mass in the tail of the pancreas, and magnetic resonance imaging (MRI) showed some tumors in the head and tail of the pancreas. The patient was asymptomatic and allergic to contrast medium. Therefore we could not perform contrast CT/MRI for further examination to diagnose pancreatic tumors. We undertook endoscopic ultrasonography (EUS) and detected a hypervascular and low echoic mass; tumor tissues were obtained by EUS-guided fine-needle aspiration (EUS-FNA). Pathological diagnosis revealed pancreatic metastasis of clear cell RCC; this was similar to the pathological findings of tumor tissues initially obtained by nephrectomy. EUS-FNA was extremely useful for the definitive diagnosis of a rare type of pancreatic tumor.