Which CT feature would most strongly support a diagnosis of renal cell carcinoma in a renal mass?

• A. A small, non-enhancing lesion
• B. A uniformly enhancing, homogeneous lesion
• C. A lesion with rapid wash-in and wash-out and heterogeneous enhancement
• D. Hypervascular enhancement with heterogeneous texture

Answer: (D)

Renal cell carcinoma shows a distinctive vascular pattern on contrast-enhanced CT. The tumor is typically highly vascular, taking up a lot of contrast, especially in the arterial phase, and its internal structure is often irregular because of necrosis, hemorrhage, and fibrous components. This combination—marked hypervascular enhancement with heterogeneous texture inside the mass—is the strongest imaging clue pointing to RCC among renal masses.

A small non-enhancing lesion is more suggestive of a simple cyst or a non-neoplastic process. A uniformly enhancing, homogeneous lesion fits more with benign or less aggressive lesions. A lesion with rapid wash-in and wash-out and heterogeneous enhancement can occur with RCC, but the most characteristic feature is the overall hypervascularity paired with internal heterogeneity.