Clear cell renal cell carcinoma: multiphasic multidetector CT imaging features help predict genetic karyotypes.

PURPOSE

To determine whether imaging characteristics at multiphasic multidetector computed tomography (CT) correlate with common karyotypic abnormalities in patients with clear cell renal cell carcinomas (ccRCCs).

MATERIALS AND METHODS

Institutional review board approval was obtained, and informed consent was waived for this HIPAA-compliant retrospective study. From January 2000 through September 2007, the prenephrectomy multiphasic (corticomedullary, nephrographic, and excretory phases), multidetector helical CT images of 58 histologically proved and karyotyped ccRCCs were reviewed by two readers with experience in abdominal imaging. Imaging features assessed included degree of attenuation, contour, and presence of calcifications and neovascularity. These features were independently correlated with specific karyotypic abnormalities on the resected specimens. Degree of attenuation data were analyzed with logistic regression for significance (P < .05), and morphologic characteristics were analyzed with odds ratios for assessing their diagnostic power.

RESULTS

On unenhanced scans, 7% (two of 28) of ccRCCs with the loss of chromosome 3p were calcified, whereas 37% (11 of 30) of lesions without this anomaly were calcified (odds ratio, 0.13). During the corticomedullary phase, ccRCCs with the loss of chromosome Y enhanced more than those without this anomaly (130.0 vs 102.5 HU, P = .04), and ccRCCs with trisomy 7 enhanced less than those without this anomaly (105.8 vs 139.3 HU, P = .04). During the excretory phase, ccRCCs with trisomy 5 enhanced more than those without this anomaly (115.5 vs 83.4 HU, P = .03).

CONCLUSION

The genetic makeup of ccRCCs affects their imaging features at multidetector CT examinations. Multidetector CT imaging characteristics may help suggest differences at the cytogenetic level among ccRCCs.