[99] Distribution of Sarcoma Histotypes and Subtypes in Selected Regions of France and Italy: A Report from CONTICANET Network of Excellence

MC Montesco, AP Dei Tos, JM Coindre, D Ranchere-Vince, A Frasson, S Albert, C Bellera, A Lurkin, CR Rossi, F Ducimetiere, I Ray-Coquard, JY Blay. University of Padua School of Medicine, Padua, Italy; General Hospital of Treviso, Treviso, Italy; Institut Bergonié, Bordeaux, France; Centre Léon Bérard, Lyon, France

Background: Soft tissue tumours represents a broad and morphologically heterogeneous group of neoplasms accounting for less than 1 % of malignancies. The distribution of histological types and subtypes has significantly changed over the time as a result of the evolution of classification schemes as well as of the lack of diagnostic expertise in non referral centers.
Design: All soft tissue and visceral sarcomas occurring in patients living in 3 european regions (Veneto Italy, Aquitaine and Rhone-Alpes, France) have been collected prospectively during 2007. 804 cases were reviewed by specialist soft tissue pathologists and reclassified according to the 2002 WHO classification in order to analyzed the distribution of the histological type and subtypes.
Results: There were 526 soft tissue sarcomas and 278 visceral sarcomas. Among the soft tissue sarcomas, the most frequent histotypes were liposarcoma (23,6%), leiomyosarcoma (13,9%) sarcoma NOS (13,3%). Well differentiated liposarcoma accounted for about half of liposarcoma (45,7%), followed by dedifferentiated liposarcoma (25,6%), myxoid/round cells liposarcoma (13,9%) and pleomorphic liposarcoma (5.4%). Rarer histotypes included angiosarcoma (4,6%), rhabdomyosarcoma (3.8%), synovial sarcoma (2.7%), Ewing's sarcoma/PNET (2.3%), MPNST (1.3%). respectively. Undifferentiated pleomorphic sarcomas (ex-MFH) accounted only for 3.8% of all cases. Among the visceral tumors GISTs was the most frequent histology (62,9%) followed by leiomyosarcoma (15,5%).
Conclusions: Approximately 13% of sarcomas remains unclassifiable even when reviewed by an expert panel of soft tissue pathologists. At variance with recently published data undifferentiated pleomorphic sarcomas accounts for less than 4%, possibly reflecting more accurate classification. Dedifferentiated liposarcoma appears to be the second most frequent liposarcoma subtype reflecting the decline of MFH. GIST is the most frequent sarcoma type at visceral sites.
Category: Bone & Soft Tissue

Monday, March 22, 2010 1:00 PM

Poster Session II # 10, Monday Afternoon


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