Mesenchymal chondrosarcoma: clinicopathologic study of 20 cases.
BACKGROUND
Mesenchymal chondrosarcoma is a rare, high-grade malignancy of bone or soft tissue with a unique, biphasic histology and poor prognosis. Because of its rarity and variable length of disease-free survival, the natural history of the disease remains poorly understood.


OBJECTIVE
To present clinical, radiographic, and histopathologic features of mesenchymal chondrosarcoma from one of the largest case series collected by a single, senior-level bone pathologist.


METHODS
Twenty cases were reviewed in consultations spanning 45 years.


RESULTS
Eighteen tumors (90%) originated in bone, and 2 tumors (10%) were of extraskeletal origin. Of the skeletal tumors, locations included craniofacial bones (n  =  9; 50%), ribs and chest wall (n  =  4; 22%), sacrum and spinal elements (n  =  3; 17%), and lower extremities (n  =  2; 11%), whereas soft tissue tumors were located about the scapula (n  =  1; 50%) and lower extremity (n  =  1; 50%). Plain radiographs demonstrated calcified, osteolytic lesions with extraosseous extension. Typical histologic features were identified consisting of small, round or spindled cells, interspersed with hyaline cartilage islands. Seventeen patients (85%) were treated surgically, and 8 patients (40%) received adjuvant treatment. Seven patients (35%) were living at last follow-up, 1.8 to 12.5 years after diagnosis, and 8 patients (40%) died between 1.2 and 21.8 years after diagnosis.


CONCLUSIONS
Mesenchymal chondrosarcoma presents multiple challenges. Diagnostic pitfalls include inadequate biopsy samples, which may result in sample error. Sox9 has been proposed as a unique marker for mesenchymal chondrosarcoma which may improve diagnostic specificity. Treatment and prognosis vary considerably. Patients who receive surgery and chemotherapy seem to fare better. Multicenter studies with higher sample numbers may improve our understanding of this malignancy.
Department of Orthopaedic Surgery, Montefiore Medical Center, Bronx, New York 10467, USA.
Rachel J
RJ
Shakked
David S
DS
Geller
Richard
R
Gorlick
Howard D
HD
Dorfman
D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D002648:Child; D018211:Chondrosarcoma, Mesenchymal / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011379:Prognosis; D011859:Radiography; D012189:Retrospective Studies; D055758:SOX9 Transcription Factor / Q000378:metabolism; D015996:Survival Rate; D055815:Young Adult
D014408:Biomarkers, Tumor; D055758:SOX9 Transcription Factor; C527932:SOX9 protein, human