Metastatic renal cell carcinoma to the pancreas and subcutaneous tissue 10 years after radical nephrectomy: a case report

BACKGROUND: Synchronous renal cell carcinoma metastasizing to the pancreas and subcutaneous tissue is very rare. Unusual metastatic sites require attention during follow-up of renal cell carcinoma. It is extremely rare for renal cell carcinoma to metastasize to the pancreas; it is also very rare for it to metastasize to the subcutaneous tissue and extremely rare for it to synchronously metastasize to the pancreas and subcutaneous tissue almost a decade after radical nephrectomy. It is well known that most pancreatic tumors are primary pancreatic adenocarcinoma. However, the pancreas can also be an uncommon site for metastasis. We present a rare case of synchronous metastasis of renal cell carcinoma to the pancreas and subcutaneous tissue; we believe it to be only the second such case reported to date. CASE PRESENTATION: We describe a case of a 74-year-old Chinese man who was diagnosed with metastatic renal cell carcinoma to the pancreas and subcutaneous tissue at the same time, 10 years after left radical nephrectomy. He received distal pancreatectomy with spleen preservation plus resection of the subcutaneous tissue lesions on the left side of the anterior abdominal wall and right waist. Pathology showed that all resected metastatic tumors were of the clear cell type. The patient was seen in regular follow-up afterward. CONCLUSION: Synchronous metastatic renal cell carcinoma to the pancreas and subcutaneous tissue is very rare, and it might occur after primary tumor resection. Patients must undergo lifelong monitoring and follow-up with regular examination so that any possible metastasis can be detected early. The optimal resection strategy should involve adequate resection margins and maximal tissue preservation of the pancreas, because renal cell carcinoma metastasizing to the pancreas and subcutaneous tissue has a good prognosis with long-term survival.