Clear cell renal cell carcinoma: multiphasic MDCT enhancement can predict the loss of chromosome 8p.

PURPOSE: To investigate whether imaging features on multiphasic multidetector computed tomography (MDCT) can predict the loss of chromosome 8p in clear cell renal cell carcinomas (RCCs), a cytogenetic abnormality associated with a higher tumor grade and greater risk of recurrence.

METHODS: With IRB approval for this HIPAA-compliant retrospective study, we queried our institution's pathology database to derive all histologically proven cases of clear cell RCC with preoperative multiphasic MDCT with as many as four phases (unenhanced, corticomedullary, nephrographic, and excretory) from January 2000 to July 2010. Of 170 clear cell RCCs with preoperative multiphasic MDCT, 105 clear cell RCCs, representing 98 unique patients, had karyotypes of the resected specimens. Lesions were evaluated for magnitude and pattern of enhancement, contour, neovascularity, calcifications, and size.

RESULTS: The corticomedullary phase mean enhancement of clear cell RCCs with a loss of 8p was significantly greater than that of clear cell RCCs without a loss of 8p (169.5 vs. 127.2 HU, p = 0.004). A threshold of 165 HU predicted the loss of 8p in clear cell RCCs with an accuracy of 78% (69/88), a specificity of 81% (62/77), and a negative predictive value of 94% (62/66). There were no significant differences in the pattern of enhancement, contour, neovascularity, calcification, or size between clear cell RCCs with a loss of 8p and those without this abnormality.

CONCLUSION: Enhancement on multiphasic MDCT can predict the loss of 8p in clear cell RCCs and can thus provide a non-invasive means of guiding further management, including surgery, ablation, watchful waiting, or medical management.