title: Synchronous multicentric osteosarcoma: the case for metastases.
abstract: OBJECTIVE
  There is a current debate whether multicentric osteosarcoma represents synchronous multiple primary osteosarcomas or metastatic disease. The purpose of this report is to evaluate the etiology, presentation, and classification of this entity.
  
  
  METHODS
  Six patients ranging in age from 7 to 29 years were studied. The clinical, radiographic, and pathologic findings are reported. In addition, a review of the literature was undertaken.
  
  
  RESULTS
  The clinical courses of our six patients as well as a review of the literature suggest that multicentric osteosarcoma represent one extreme of a continuous scale of metastatic osteosarcoma rather than multiple synchronous primary tumors. The presentation is unusual and the clinical behavior distinctive, but the mechanism of spread remains the same: blood-borne and lymphatic-borne.
  
  
  CONCLUSIONS
  Our experience with these six patients supports the concept in the recent literature that synchronous osteosarcoma is one extreme of the spectrum of metastatic osteosarcoma. Its unique features are: (1) multiple radiodense lesions that present simultaneously with or without pulmonary metastases; (2) a single "dominant" lesion with multiple smaller lesions; and (3) a uniformly rapid, fatal prognosis. Osteosarcoma should be regarded as a metastatic disease, even when only a single primary lesion is found at the initial presentation.
authors.affiliation: Department of Diagnostic Radiology, Allegheny General Hospital, Pittsburgh, PA 15212-4772, USA.
authors.forename: R H
authors.initials: RH
authors.lastname: Daffner
authors.forename: S L
authors.initials: SL
authors.lastname: Kennedy
authors.forename: K R
authors.initials: KR
authors.lastname: Fox
authors.forename: J J
authors.initials: JJ
authors.lastname: Crowley
authors.forename: D D
authors.initials: DD
authors.lastname: Sauser
authors.forename: L A
authors.initials: LA
authors.lastname: Cooperstein
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D002648:Child; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D009378:Neoplasms, Multiple Primary; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000556:secondary; D014057:Tomography, X-Ray Computed