title: Small (<4 cm) clear cell renal cell carcinoma: correlation between CT findings and histologic grade.
abstract: To evaluate the correlation between CT findings and histologic grade of small clear cell renal cell carcinoma (ccRCC).
  
  
  
  CT scans of 101 patients with small ccRCC were reviewed independently by two radiologists for tumor size, shape, margin, encapsulation, enhancement pattern, and visual relative enhancement. Enhancement patterns were defined according to the percentage of uniform enhancement [pattern 1, homogeneous (≥90%); pattern 2, relatively homogeneous (≥75 and <90%); and pattern 3, heterogeneous (<75%)]. Quantitative parameters representing attenuation and degree of enhancement were calculated. Histologic grade was classified as low (Fuhrman grade I or II) and high (Fuhrman grade III or IV). CT imaging variables were analyzed using univariate and multivariate analyses.
  
  
  
  A total of 63 low-grade and 38 high-grade small ccRCCs were assessed. Low-grade tumors differed from high-grade tumors with respect to enhancement pattern 1 or 2 (p < 0.001 and p < 0.001), smaller size (p = 0.002 and p = 0.001), and lower attenuation on unenhanced scan (p < 0.001 and p = 0.008). In multivariate analysis, enhancement pattern 1 or 2 and low attenuation (≤30 HU) were identified as independent predictors of low-grade ccRCC. Accuracy derived from logistic regression analysis was 79.2% for reader 1 and 70.3% for reader 2.
  
  
  
  CT imaging features including tumor attenuation and enhancement pattern can be useful to predict the biologic behavior of small ccRCC for adequate treatment strategy.
authors.affiliation: Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Soo Yeon
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea. urorad@korea.ac.kr.
authors.forename: Deuk Jae
authors.initials: DJ
authors.lastname: Sung
authors.affiliation: Department of Biostatistics, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Kyung Sook
authors.initials: KS
authors.lastname: Yang
authors.affiliation: Department of Radiology, Guro Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Kyeong Ah
authors.initials: KA
authors.lastname: Kim
authors.affiliation: Department of Radiology, Ansan Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Suk Keu
authors.initials: SK
authors.lastname: Yeom
authors.affiliation: Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Ki Choon
authors.initials: KC
authors.lastname: Sim
authors.affiliation: Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Na Yeon
authors.initials: NY
authors.lastname: Han
authors.affiliation: Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Beom Jin
authors.initials: BJ
authors.lastname: Park
authors.affiliation: Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Min Ju
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Sung Bum
authors.initials: SB
authors.lastname: Cho
authors.affiliation: Department of Pathology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Jeong Hyeon
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D007479:Iopamidol / Q000031:analogs & derivatives; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; C057937:iomeprol; C093233:iobitridol; D007472:Iohexol; D007479:Iopamidol
keywords: Carcinoma, renal cell; Clear cell renal cell carcinoma; Contrast media; Kidney neoplasms; Multidetector computed tomography