title: Renal Masses Detected on FDG PET/CT in Patients With Lymphoma: Imaging Features Differentiating Primary Renal Cell Carcinomas From Renal Lymphomatous Involvement.
abstract: OBJECTIVE
  The purpose of this study is to analyze the18F-FDG PET/CT features of solid renal masses detected in patients with lymphoma and to evaluate the ability of PET/CT to differentiate renal cell carcinoma (RCC) from renal lymphomatous involvement.
  
  
  METHODS
  Thirty-six patients with solid renal masses on PET/CT performed for staging or follow-up of lymphoma were evaluated retrospectively. The features recorded for each renal mass included the following standardized uptake values (SUVs) on PET/CT: the maximum SUV (SUVmax), the mean SUV (SUVmean), the ratio of the SUVmaxof the tumor to that of the normal kidney cortex, the ratio of the SUVmeanof the tumor to that of the normal kidney cortex, the ratio of the SUVmaxof the tumor to that of the normal liver, and the ratio of the SUVmean of the tumor to that of the normal liver. Renal mass size and margins (well defined vs infiltrative) and the presence of calcifications were evaluated on CT. Renal biopsy results were used as the reference standard. Relationships between imaging parameters and histopathologic findings were assessed.
  
  
  RESULTS
  Of the 36 renal masses evaluated, 22 (61.1%) were RCCs and 14 (38.9%) were renal lymphomas. All SUV metrics were higher for renal lymphomas than for RCCs (p < 0.0001, for all). All renal lymphomas had an SUVmaxhigher than 5.98 g/mL (median, 10.99 g/mL), whereas all RCCs had an SUVmaxlower than 5.26 g/mL (median, 2.91 g/mL). No statistically significant differences in mass size or margins were found between RCCs and renal lymphoma.
  
  
  CONCLUSIONS
  PET/CT features may be useful for differentiating RCCs from renal involvement in patients with lymphoma with solid renal masses.
authors.affiliation: 1 Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065.|2 Department of Radiology, Hospital Clinic, Villarroel 170, 08036 Barcelona, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Nicolau
authors.affiliation: 1 Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065.
authors.forename: Evis
authors.initials: E
authors.lastname: Sala
authors.affiliation: 3 Lymphoma Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Anita
authors.initials: A
authors.lastname: Kumar
authors.affiliation: 4 Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Debra A
authors.initials: DA
authors.lastname: Goldman
authors.affiliation: 1 Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065.
authors.forename: Heiko
authors.initials: H
authors.lastname: Schoder
authors.affiliation: 1 Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065.
authors.forename: Hedvig
authors.initials: H
authors.lastname: Hricak
authors.affiliation: 1 Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065.
authors.forename: Hebert Alberto
authors.initials: HA
authors.lastname: Vargas
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008223:Lymphoma / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: CT; PET; cancer; lymphoma; renal cell carcinoma