title: Comparison of radiographic and pathologic sizes of renal tumors.
abstract: OBJECTIVE
  The determination of the size of a renal tumor is important for staging, prognosis and selection of the appropriate surgical treatment. We investigated the difference of radiographic and pathologic size of renal tumors in a contemporary cohort of patients who underwent nephron sparing surgery and evaluated its clinical implications.
  
  
  METHODS
  The records of 169 patients who received nephron sparing surgery for renal lesions suspicious for malignancy between January 2006 and December 2010 were reviewed retrospectively. Radiographic tumor size, defined as the largest diameter of tumor measured by CT images, and pathologic size, the largest diameter of tumor measured in the surgical specimen, were compared and analyzed.
  
  
  RESULTS
  Among all subjects, mean radiographic and pathologic tumor size were 3.25 ± 1.78 cm and 3.03 ± 1.91 cm, respectively (P < 0.001), with a discrepancy of just 0.22 cm. When the patients were categorized according to radiographic tumor size in the 1 cm range, the mean radiographic tumor size was significantly greater than pathologic tumor size in the following groups: 2 to 3 cm (P < 0.001), 3 to 4 cm (P < 0.001), and 4 to 5 cm (P = 0.028). When radiographic and pathologic tumor sizes were compared according to the pathologic tumor subtype, a significant difference was observed only among those with clear cell renal carcinoma (P < 0.001).
  
  
  CONCLUSIONS
  Renal tumor size was overestimated by radiography as compared with pathology. The difference was just 0.22 cm with little clinical significance, suggesting that CT provides an accurate method to estimate renal tumor size preoperatively.
authors.affiliation: Department of Urology, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Linhui
authors.initials: L
authors.lastname: Wang
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Yinghao
authors.initials: Y
authors.lastname: Sun
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009399:Nephrons / Q000601:surgery; D012016:Reference Values; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden; D055815:Young Adult