Clear Cell Papillary Renal Cell Carcinoma: A Recent Entity With Distinct Imaging Patterns

Area of Science:

• Urology
• Radiology
• Oncology

Background:

• Clear cell papillary renal cell carcinoma (RCC) is a recently classified, indolent renal tumor.
• It is the fourth most common histologic type of renal cell carcinoma.

Purpose of the Study:

• To describe the imaging features of clear cell papillary RCC.
• To correlate imaging findings with clinical and pathologic characteristics.

Main Methods:

• Retrospective analysis of 27 patients with 44 clear cell papillary RCC tumors.
• Preoperative CT or MRI imaging was reviewed by two independent radiologists.

Main Results:

• Two main imaging patterns were identified: solid (52%) and cystic (48%).
• Solid tumors showed T2 hyperintensity and early enhancement with delayed washout.
• Cystic tumors were predominantly unilocular and classified as Bosniak IV, III, or IIF.

Conclusions:

• Clear cell papillary RCC demonstrates two distinct imaging patterns: cystic and solid.
• Solid clear cell papillary RCC imaging characteristics are distinct from papillary RCC and similar to clear cell RCC.