Abstract:Objective: To investigate the relationship between dynamic enhanced MDCT and histopathologic findings of the collecting duct carcinoma(CDC), in order to improve diagnostic accuracy. Methods: Seven cases with pathologically proven CDC of the kidney underwent spiral CT plain scan, post-contrast cortico-medullary phase and nephrographic phase scans before surgery. Results: All of the 7 tumors presented normal renal contour with tumor located in renal medullary. All tumors manifested an infiltrative growth pattern and were ill-defined, and displayed an interlocking arrangement with the surrounding normal renal parenchyma, no capsule was found. The tumor density was correlated with the composition of tumor in pathology. The CT value of the solid component on plain scan images was 30.1~44.7HU(mean=35.5HU), after contrast enhancement, the CT value of tumor on cortico-medullary phase images and nephrographic phase images was 34.2~72.0HU(mean=52.7HU) and 40.0~89.3HU(mean=74.5HU) respectively. Progressive delayed enhancement after contrast enhancement was related to pathologically apparent stromal reaction and fibrosis, while the fibrous stroma often manifested a delayed enhancement. Conclusion: The CT characteristics of CDC were different from the other renal cell carcinoma and the image findings are closely related to pathology.