Transitional cell and clear cell renal carcinoma: differentiation of distinct histological types with multiphase CT.
BACKGROUND
Transitional cell carcinoma (TCC) may mimic renal cell carcinoma (RCC) when it develops in a similar location, therefore, differentiation with imaging techniques might be challenging. Preoperative differentiation may have a significant role indicating the type of surgical treatment (nephrectomy vs. ureteronephrectomy).


OBJECTIVE
To retrospectively analyze the differences in the contrast enhancement of TCC and RCC.


METHODS
Images of 20 RCC and 12 TCC (mean ages, 62.3 ± 14.1 and 67.4 ± 12.0 years, respectively) were analyzed from patients who underwent multiphase computed tomography (CT) examinations following 1.5 mL/kg non-ionic contrast agent administration. Unenhanced corticomedullary (30-45 s), nephrographic (70-90 s), and excretory (300-480 s) phases were imaged. The attenuation characteristics of RCC and TCC were compared to the attenuation of the normal renal cortex.


RESULTS
Significant differences were found in the attenuation ratios between RCC or TCC in the corticomedullary (P = 0.040) and nephrographic (P = 0.004) phases using three regions of interest (ROIs) of 10 mm(2) size. If measuring ROIs comprising the complete tumor lesion instead of three small ROIs, no significant difference was observed in the attenuation ratios between RCC in TCC in any phases.


CONCLUSIONS
Our study reports significant attenuation differences between RCC and TCC in the corticomedullary and nephrographic phases by multiphase CT. The findings underscore the importance of multiphase CT in the differentiation of these two different entities. Using multiple small (three) ROIs is more accurate than measuring the whole tumor attenuation.
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary bata_pal@yahoo.co.uk.
Pal
P
Bata
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
David Laszlo
DL
Tarnoki
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
Adam Domonkos
AD
Tarnoki
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
Pal Kaposi
PK
Novak
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
Janos
J
Gyebnar
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
Dora
D
Kekesi
Department of Urology, Semmelweis University, Budapest, Hungary.
Attila
A
Szendroi
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
Bence
B
Fejer
Second Department of Pathology, Semmelweis University, Budapest, Hungary.
A Marcell
AM
Szasz
Department of Urology, Semmelweis University, Budapest, Hungary.
Peter
P
Nyirady
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
Kinga
K
Karlinger
Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
Viktor
V
Berczi
D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D002295:Carcinoma, Transitional Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D014283:Triiodobenzoic Acids
D003287:Contrast Media; D014283:Triiodobenzoic Acids; D007472:Iohexol; C038192:iopromide; C044834:iodixanol; C054871:ioversol
CT; Central renal tumor; renal cell carcinoma; renal neoplasms; renal pelvis; transitional cell carcinoma