title: [Magnetic resonance imaging findings of Chromophobe renal cell carcinoma].
abstract: OBJECTIVE
  To document the MRI features of Chromophobe cell carcinoma and to explore whether MR features vary with the tumor size.
  
  
  METHODS
  MRI features of 34 patients (16 male, 18 female, age range from 24 - 61, average age is 49 years old), totally 35 focuses with histologically proved chromophobe cell carcinoma were studied retrospectively. All the patients underwent MR plain and dynamic contrast-enhanced scan before their surgery. Variation of signal intensity (3D LAVA) and ADC values of the lesions, and the analysis of images of T1WI, T2WI and chemical shift were all evaluated on the GE Advantage 4.4 work station. All lesions were categorized into 2 groups (tumor diameter ≤ 4 cm, or > 4 cm). The difference of imaging characteristics between these two groups was analyzed using Fisher exact test. Signal intensity variation and ADC values were analyzed by using one-way ANOVA method.
  
  
  RESULTS
  None of the 35 cases contained fat or lipid. On T2WI 27 cases showed slightly low signal intensity (77.1%). In all cases, 4 appeared local cystic change (11.4%); 4 spotty hemorrhage (11.4%); 5 necrosis (covering less than 20% of whole tumor) (14.2%); 30 clear pseudo capsule (85.7%); 29 round-like lesions (the difference among the length, width and height was within 0.5 cm) (82.8%); and no cases showed signs of invasiveness or metastasis. The average changes of signal intensity of all the 35 cases were 119.8% on cortex period, 176.4% on medulla period and 154.5% on delayed phase. The mean ADC value of tumor was 1.08 ± 0.28×10(-3)mm(2)/s. 35 lesions were divided into two groups , 21 in group 1(diameter ≤ 4 cm) and 14 in group 2 (diameter > 4 cm). Cystic degeneration was seen in 0/21 in group 1 versus 4/14 in group 2 respectively, and hemorrhage 0/21 versus 4/14, necrosis 0/21 versus 5/14 , central scar 2/21 versus 8/14. The difference of these findings between two groups demonstrated statistical significance (P < 0.05). Variation of signal intensity and ADC values in two groups has no statistical significance.
  
  
  CONCLUSIONS
  The MR features of Chromophobe renal cell carcinoma were hypointensity on T2WI, clear pseudocapsule, However, cystic degeneration, hemorrhage, necrosis and central scar are more common in larger tumors.
authors.affiliation: Department of Radiology, General Hospital of Chinese People's Liberation Army, Beijing 100853, China.
authors.forename: Xin-kun
authors.initials: XK
authors.lastname: Wang
authors.forename: Hai-yi
authors.initials: HY
authors.lastname: Wang
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.forename: Ying-wei
authors.initials: YW
authors.lastname: Wang
authors.forename: Ye
authors.initials: Y
authors.lastname: Wang
authors.forename: Ye-huan
authors.initials: YH
authors.lastname: Tang
authors.forename: Hui-yi
authors.initials: HY
authors.lastname: Ye
mesh_terms: D000328:Adult; D002292:Carcinoma, Renal Cell / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies