title: Extraskeletal mesenchymal chondrosarcoma.
abstract: Among seven patients with extraskeletal mesenchymal chondrosarcoma (EMC), three children (aged 3-6 years) developed EMC in a central location and four adults (aged 38-54 years) developed EMC in both central and peripheral sites. Conventional radiography and tomography and computed tomography (CT) depicted EMC as a soft-tissue mass with ring, arc, stippled, and highly opaque calcifications in four patients. Contrast-enhanced CT showed lobulation and peripheral tumoral enhancement, sometimes with central low-attenuation areas. On magnetic resonance (MR) images, EMC was a lobulated mass with high signal intensity on T2-weighted images and enhancement with low-signal-intensity focal areas on contrast-enhanced T1-weighted images. All adults developed recurrences and/or metastases and died. Of the three children, two were living and free of disease at the end of the study and the third child died of chemotherapeutic-induced leukemia. Although imaging features of EMC are nonspecific, its chondroid-type calcifications and foci of low signal intensity within enhancing lobules may reflect its dual histopathologic morphologic characteristics of differentiated cartilage islands interspersed within vascular undifferentiated mesenchyme.
authors.affiliation: Department of Radiology, Institut Gustave-Roussy, Villejuif, France.
authors.forename: L G
authors.initials: LG
authors.lastname: Shapeero
authors.forename: D
authors.initials: D
authors.lastname: Vanel
authors.forename: D
authors.initials: D
authors.lastname: Couanet
authors.forename: G
authors.initials: G
authors.lastname: Contesso
authors.forename: L V
authors.initials: LV
authors.lastname: Ackerman
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D002813:Chondrosarcoma / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000401:mortality; D003238:Connective Tissue / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012983:Soft Tissue Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000401:mortality; D014057:Tomography, X-Ray Computed