title: Differential diagnostic value of "blue reticulated chondroid-like material" in aneurysmal bone cysts: a classic histopathologic analysis of 215 cases.
abstract: OBJECTIVE
  Our classic histopathologic study of aneurysmal bone cyst (ABC) revealed that "blue reticulated chondroid-like material" (BRC) is characteristic of ABC.
  
  
  METHODS
  The light microscopic findings were retrospectively analyzed in 215 cases of ABC, including 101 primary and 114 secondary cases. In addition, 22 cases of telangiectatic osteosarcoma (TOS) were drawn from the same source and used as a control.
  
  
  RESULTS
  We found the presence of typical BRC in 24 (23.8%) of 101 cases of primary ABC and in six (5.3%) of 114 cases of secondary ABC, with an overall incidence of 30 (14%). None of the cases of TOS showed BRC. BRC was significantly more common in primary ABC than in secondary ABC (P < .05) and in patients 19 years or younger than in those 20 years or older (P < .05).
  
  
  CONCLUSIONS
  BRC appears to be a unique histopathologic feature of ABC, making it valuable to differentiate benign ABC from TOS. Simple H&E stain can be economically performed anywhere.
authors.affiliation: From the Department of Orthopaedic Surgery, Uijeongbu St Mary's Hospital, The Catholic University of Korea, Seoul; and wjbahk@catholic.ac.kr.
authors.forename: Won-Jong
authors.initials: WJ
authors.lastname: Bahk
authors.affiliation: Orthopaedic Hospital, Los Angeles, CA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Mirra
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017824:Bone Cysts, Aneurysmal / Q000175:diagnosis*; D001859:Bone Neoplasms / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000175:diagnosis*; D012189:Retrospective Studies; D055815:Young Adult
keywords: Aneurysmal bone cyst; Blue reticulated chondroid-like material; Telangiectatic osteosarcoma