Background: Late metastasizing into pancreatic tissue is a special hallmark of renal cell carcinomas (RCC). A very low prevalence leads to scarce data about therapy, prognosis and spreading pathways. The aim of the study was to analyze whether a high fat content in the pancreas facilitates RCC metastases formation. A model for density measurement of pancreatic tissue has been developed and evaluated. Pancreatic fat content was measured comparing Hounsfield units (HU) of CT scans.
Methods: In a consecutive single centre retrospective database of 3600 patients with pancreatic resections, only 12 patients (0.3%) cases of RCC metastases in the pancreas were found. HU were measured in 3 pancreatic regions: head, body and tail in patients' CT scans. HU values were compared to a control population and results aligned with recent literature.
Results: We revealed a prevalence of pancreatic metastases of RCC in 0.3% of cases. The formation of RCC in the pancreas occurred within 14 ± 5.6 years after initial diagnosis of RCC. 83.3% of the patients were alive after a follow-up period of up to 48 months. Clinical data analysis revealed an affinity for metastatic formation to lipomatous pancreas. This could be objectivized by HU analysis in CT scans.
Conclusion: Pancreatic metastases occur late after the first diagnosis of renal carcinoma and show an affinity for lipomatous pancreatic tissues. Due to its rarity in occurrence, multicentric studies are highly recommended to further analyze this correlation between fatty pancreas and RCC.
Keywords: Renal cell carcinoma; lipomatous pancreas; metastasis; pancreatic surgery; secondary pancreatic tumor.