condrosarcoma

Chondrosarcoma is a malignant tumor that produces cartilaginous matrix and arises from cartilage-producing cells within bone or from preexisting cartilaginous tissue. It is among the most common primary malignant bone tumors in adults, typically presenting in the 40s to 70s, with a slight male predominance. Conventional chondrosarcoma is the most frequent subtype.

Pathology: Conventional chondrosarcomas are graded I–III by cellularity, nuclear atypia, and mitotic activity. Low-grade tumors have lobulated hyaline cartilage with mild atypia, while high-grade tumors show marked dedifferentiation and more aggressive behavior. Dedifferentiated and mesenchymal subtypes are more aggressive and have poorer outcomes.

Clinical features: Patients usually present with localized, insidious bone pain and sometimes a palpable mass. The pelvis, proximal femur, and proximal humerus are common sites. Symptoms may be present for months to years before diagnosis. Pathologic fracture can occur with cortical destruction.

Diagnosis and imaging: Plain radiographs typically reveal a lytic lesion with endosteal scalloping and characteristic rings or arcs of calcification within a cartilaginous matrix. CT and MRI assess extent, medullary involvement, and soft-tissue extension. Definitive diagnosis requires a biopsy, with careful distinction from enchondroma and other cartilaginous tumors.

Treatment and prognosis: The mainstay is wide surgical excision with negative margins; limb-sparing procedures are common. Conventional chondrosarcoma is relatively resistant to chemotherapy and radiotherapy; radiotherapy may be used for unresectable tumors or palliation, and chemotherapy is reserved for high-grade, dedifferentiated, or mesenchymal variants. Five-year survival varies by grade and site, generally higher for low-grade tumors.

Follow-up includes regular imaging due to risk of local recurrence and pulmonary metastasis, particularly for higher-grade disease.