MULTICENTRIC CHONDROSARCOMAS

Multicentric chondrosarcomas, other than those from mesenchymal chondr oma, are rare and difficult to differentiate from metastatic disease, Eight new patients with multicentric chondrosarcomas are reported, Fiv e patients had chondrosarcomas that were monomelic, 3 had disseminated chondrosarcomas, 3 had synchronous involvement, and 5 had metachronou s involvement; 1 patient had Ollier's disease, A bimodal age distribut ion was apparent: 4 patients were between 62 and 76 years old, and the remaining 4 were between 16 and 33 years old, Average duration of fol lowup was 6 years, 4 months, Each of the patients with synchronous cho ndrosarcomas had single bone lower extremity involvement and presented with symptoms occurring at only 1 of the 2 sites of tumor, Each of th e 5 patients with metachronous chondrosarcomas experienced involvement of a different bone when the second tumor presented, Only 1 of these metachronous chondrosarcomas was limited to the lower extremity, The s econd tumor occurred in all patients after excellent control of the pr imary tumor by wide excision, The average duration between diagnosis o f the 2 tumors was 4 years, 4 months (range, 8 months-12 years, 9 mont hs), Patients who had nonmonomelic malignancies must be viewed with a considerably more guarded prognosis than those who had monomelic chond rosarcoma because each of the 2 deaths resulting from progressive dise ase occurred among the 3 patients with nonmonomelic chondrosarcoma. Th e nonmonomelic malignancies may represent metastatic chondrosarcoma wi th a rare predilection to bony involvement. Monomelic chondrosarcoma s imply may represent lesions analogous to the skip lesions observed in osteosarcoma.