ABSTRACT: Areas of lower enhancement on computed tomography are frequently seen in renal-cell carcinoma. We investigated whether tumor enhancement on the most prominent hypodense areas correlates with the nuclear grade and other pathologic variables.
From 2004 to 2009, all consecutive patients with a preoperative tomography who underwent radical or partial nephrectomy for renal-cell carcinoma at our tertiary referral center were retrospectively analyzed. Enhancement of the entire tumor on the slice with most prominent areas of lower enhancement was determined.
Forty-eight patients were included. Clear-cell carcinoma comprised 91.6 %. Mean areas of lower enhancement for nuclear grade tumors 1-4 were 67.4, 38.7, 27.9, and 15.1 HU, respectively. Areas of lower enhancement negatively correlated with size, nuclear grade, T stage, and pathological stage. Tumors with extension beyond Gerota's fascia (10.5 vs. 35.9 HU, p < 0.001) and positive surgical margins (21.2 vs. 34.8 HU, p = 0.04) had more prominent areas of lower enhancement than organ-confined tumors. When comparing nuclear grade 1-3 to nuclear grade 4 tumors, these areas were significantly lower in the later (36.5 vs. 15.1 HU, p < 0.001). Receiver-operating characteristics curves for detecting nuclear grade 4 showed an area under the curve of 0.808 (95 % CI 0.659-0.957).
Lower enhancement of the entire tumor at the point where hypodense tumor areas are more predominant on tomography is associated with higher nuclear grade and more advanced stage.
International Urology and Nephrology 05/2012; 44(5):1369-74. · 1.47 Impact Factor