E1667. Stop Worrying and Start Living: Current Update on the Management of Small Renal Masses, With Emphasis on Potential Pitfalls and Solutions
  1. Dhakshinamoorthy Ganeshan; University of Texas MD Anderson Cancer Center
  2. Tara Sagebiel; University of Texas MD Anderson Cancer Center
  3. Chitra Viswanathan; University of Texas MD Anderson Cancer Center
  4. Brinda Rao; University of Texas MD Anderson Cancer Center
  5. Sarah Palmquist; University of Texas MD Anderson Cancer Center
  6. Nicolaus Wagner-Bartak; University of Texas MD Anderson Cancer Center
  7. Catherine Devine; University of Texas MD Anderson Cancer Center
Majority of the incidentally discovered small renal lesions are benign cysts. However, a small but significant percentage of these serendipitously discovered lesions will turn out to be renal malignancies. Unfortunately, only a minor percentage of patients with renal cell carcinoma present with symptoms. Less than 10% of patients have the classic triad of flank pain, hematuria, and a palpable abdominal mass. Vast majority of localized RCC are discovered as incidental lesions on imaging performed for other indications. Although ultrasound can be helpful, CT and MR are the mainstay in the detection and characterization of renal masses.

Educational Goals / Teaching Points
Discuss how to characterize small renal masses and review the CT and MR features of various renal lesions that can mimic renal cell carcinoma

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
In this educational exhibit, we will review the CT and MR protocol used for diagnosing and characterizing renal masses. Role of the various phase including unenhanced images, corticomedullary, nephrographic and excretory phase will be reviewed. Imaging features of typical and atypical renal tumors and their differential diagnoses will be described. Emphasis will be placed on the imaging pearls and pitfalls to exclude renal cancer mimics. Role of percutaneous biopsy will be discussed.

Among the renal masses that are surgically resected for suspected renal cell carcinoma, about 40 % of the lesion < 1 cm, 21 % of the masses measuring 1-2 cm, 20 % of those measuring 2-3 cm and 17% measuring 3-4 cm are reported to be benign! Multiphasic CT or MR is critical for diagnosis. Radiologists should be aware of the various pitfalls associated with the diagnosis and avoid mischaracterization of renal cell carcinoma. Image guided biopsy may be required in specific cases for accurate diagnosis and prevent unnecessary nephrectomy, with associated morbidity and mortality.