title: Radiologic morphology of low-grade primary central nervous system lymphoma in immunocompetent patients.
abstract: OBJECTIVE
  Primary central nervous system lymphomas (PCNSLs) are usually high-grade and are rarely low-grade non-Hodgkin lymphomas (NHLs). On MR imaging, PCNSLs typically present as contrast-enhancing lesions in contact with the subarachnoid space without evidence of necrosis. We evaluated the radiologic morphology and clinical characteristics of low-grade PCNSLs, hypothesizing that they may differ from high-grade PCNSLs.
  
  
  METHODS
  Records were reviewed from 332 patients screened for inclusion in 3 multicenter prospective trials. MR imaging scans were obtained from all patients and were centrally reviewed by 2 consultant neuroradiologists.
  
  
  RESULTS
  Ten patients (3%) with low-grade PCNSLs (7 men and 3 women; median age, 59 years; age range, 19-61 years) were identified. Four patients had one lesion, 2 patients 2 lesions, and 4 patients had multiple lesions. The following radiologic features infrequently seen in high-grade PCNSLs were found in a substantial proportion of patients: location in deep structures or spine (n = 6); lack of periventricular location (n = 5); hyperintensity on T2-weighted images (n = 10); moderate or absent contrast enhancement (n = 6); and heterogeneous contrast enhancement (n = 5). In 8 patients, >2 of these features were present in at least one lesion, and, thus, the radiologic appearance was assessed atypical of high-grade PCNSLs. The atypical radiologic appearance in combination with atypical or mild symptoms resulted in a false or delayed diagnosis.
  
  
  CONCLUSIONS
  Low-grade PCNSLs may have a variable and atypical radiologic morphology compared with high-grade PCNSLs with the risk of false or delayed diagnosis.
authors.affiliation: Department of Hematology, Oncology and Transfusion Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Kristoph
authors.initials: K
authors.lastname: Jahnke
authors.forename: Andreas
authors.initials: A
authors.lastname: Schilling
authors.forename: Jens
authors.initials: J
authors.lastname: Heidenreich
authors.forename: Harald
authors.initials: H
authors.lastname: Stein
authors.forename: Mario
authors.initials: M
authors.lastname: Brock
authors.forename: Eckhard
authors.initials: E
authors.lastname: Thiel
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Korfel
mesh_terms: D000328:Adult; D016543:Central Nervous System Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007121:Immunocompetence; D008228:Lymphoma, Non-Hodgkin / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011856:Radiographic Image Enhancement; D011857:Radiographic Image Interpretation, Computer-Assisted; D016019:Survival Analysis
chemical_list: D003287:Contrast Media