title: Differentiation of renal cell carcinoma subtypes by multislice computerized tomography.
abstract: OBJECTIVE
  We differentiated renal cell carcinoma subtypes using multislice computerized tomography (CT).
  
  
  METHODS
  We reviewed the CT images of 87 patients with renal cell carcinoma. Three subtypes of renal cell carcinoma were noted, including clear cell in 37 cases, papillary in 26 and chromophobe in 24. Biphasic CT (unenhanced, corticomedullary and excretory phases) was done in all patients. We compared patient age and sex, tumor size, enhancement degree and pattern (homogeneous, heterogeneous and predominantly peripheral), the presence or absence of calcification or cystic degeneration (necrotic or hemorrhagic areas within the tumor) and tumor spreading patterns, including perinephric change, venous invasion and lymphadenopathy, in the 3 subtypes.
  
  
  RESULTS
  The degree of enhancement was significantly different among the 3 subtypes in the corticomedullary and excretory phases (p <0.001). Cystic degeneration was more evident in the clear cell subtype than in the other subtypes regardless of tumor size (p <0.001). A hypervascular pattern (higher tumor enhancement after contrast material injection due to higher vascularity) was noted in 48.6% of clear cell subtype in comparison to 15.4% of papillary and 4.2% of chromophobe subtypes (p <0.001). The chromophobe subtype showed homogeneous enhancement in 75% of cases in comparison to 45% and 65% of clear cell and papillary subtypes (p >0.05). Calcification was evident in 21.6%, 23.1% and 25% of clear cell, papillary and chromophobe subtypes, respectively (p >0.05).
  
  
  CONCLUSIONS
  To differentiate the subtypes of renal cell carcinoma the degree of enhancement is the most valuable parameter. The presence or absence of cystic degeneration, vascularity and enhancement patterns can serve supplemental role in differentiating renal cell carcinoma subtypes.
authors: Urology Department, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt. kzsheir@hotmail.com
authors: Khaled Z
authors: KZ
authors: Sheir
authors: Mohamed
authors: M
authors: El-Azab
authors: Ahmed
authors: A
authors: Mosbah
authors: Mahmoud
authors: M
authors: El-Baz
authors: Atallah A
authors: AA
authors: Shaaban
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed