COMPUTED-TOMOGRAPHY CHARACTERIZATION OF RENAL-CELL TUMORS IN CORRELATION WITH HISTOPATHOLOGY

RATIONALE AND OBJECTIVES. The authors distinguish the histomorphologic subtypes of renal cell tumors (RCTs) by computed tomography (CT), MET HODS. In a consensus conference between radiologists, pathologists, an d urologists, the CT criteria of the various subtypes of RCTs (clear c ell, chromophilic cell, chromophobic cell renal carcinoma and oncocyto ma) were established, Computed tomography scans of 65 resected RCTs we re reevaluated independently by seven radiologists, Using a numerical scoring system, they first attempted to differentiate clear cell from nonclear cell RCTs, A further attempt then was made to classify each t umor into one of the four categories, RESULTS, The sensitivity for the diagnosis of clear cell RCT was 72.5% (213 of 294 true-positive findi ngs) and 82% (132 of 161 true-positive findings) for the nonclear cell group, For tumors more than 3 cm in diameter the sensitivities were 8 0.25% for the clear cell group and 80.7% for the nonclear cell group, Specific differentiation into the four subtypes was not possible, Onco cytomas were classified correctly in only 6 of 49 observations (12.2%) . CONCLUSIONS. Small clear cell tumors often fail to show the CT chara cteristics that would permit an accurate classification, In tumors mea suring 3 cm or more, differentiation between clear cell and nonclear c ell types by means of CT criteria is possible, Nevertheless, as RCTs s how a great variation in appearance, a differentiation into subtypes o f the nonclear cell RCTs cannot be accomplished by CT, Using a uniform examination protocol and spiral scanning technique, the sensitivity o f CT in the diagnosis of the subtypes of RCTs may be able to be furthe r increased, Some tumors, especially oncocytomas, undoubtedly will rem ain diagnostic dilemmas.