- Email: [email protected]
Chondrosarcoma
Chapter 49 Chondrosarcoma
Definition: Chondrosarcoma is a malignant cartilaginous group of tumors with highly diverse features and behavior patterns that characteristically produce cartilage matrix from neoplastic tissue devoid of osteoid in which ossification, calcification, and myxoid changes can occur. Incidence: Accounts for approximately 20% of all malignant bone tumors and is second only to osteosarcoma in frequency as a primary malignant bone tumor. Peak incidence for primary or central chondrosarcomas arising de novo are between 40 and 60 years of age and between 25 and 45 years of age for secondary or peripheral chondrosarcomas, most often from preexisting benign cartilage lesions such as solitary osteochondromas, enchondromatosis syndromes (Ollier’s disease, Maffucci’s syndrome, metachondromatosis), or multiple hereditary exostoses. About 90% of all chondrosarcomas are conventional chondrosarcomas and 10% are subtypes: de-differentiated, clear-cell, mesenchymal, and myxoid. The tumors are predominantly axial, most commonly involving the pelvis, proximal femur, and proximal humerus, with the metaphysis being the most common location of long bones. There is a slight male predominance but no racial predilection. Clinical: The most common symptom at presentation is pain, which is often dull in character and present for months. Rarely, a palpable mass is present. Diagnostic Studies: Radiography is essential for the initial diagnosis with the radiographic appearance of the chondrosarcoma frequently being diagnostic. X-ray findings demonstrate a lucent lesion frequently containing a pattern of calcification described as punctuate, popcorn, or comma-shaped. There is often an aggressive appearance with cortical destruction, periosteal reaction, and an occasional soft tissue mass. Computed tomography can be helpful in identifying matrix calcifications, endosteal scalloping, and cortical destruction and as a guide in percutaneous biopsies. Magnetic resonance imaging is best for clarifying extraosseous and intramedullary tumor extension.
Fig. 49-1 De-differentiated chondrosarcoma. AP radiograph of the left femur showing a proximal femoral chondrosarcoma with an adjacent area of lytic destruction and pathologic fracture, due to associated de-differentiation to malignant fibrous histiocytoma. (From Adam A, et al: Grainger & Allison’s Diagnostic Radiology, 5th ed. Churchill Livingstone, 2008.)
100
Chondrosarcoma
• 101
Fig. 49-2 Myxoid chondrosarcoma. Lateral radiograph of the femur showing a grade II myxoid chondrosarcoma. Bone expansion indicates a more aggressive behavior. (From Adam A, et al: Grainger & Allison’s Diagnostic Radiology, Philadelphia, Churchill Livingstone, 2008.)
Histology: On gross examination, conventional chondrosarcomas appear smooth, hard, and lobulated. Microscopically, they are again lobulated, showing increased cellularity with hyperchromatic and pleomorphic binucleated or multinucleated malignant chondrocytes. Microscopic grading of conventional chondrosarcoma has prognostic value and is differentiated as follows: • Grade I (Well Differentiated): Lesions have chondrocytes with small, round nuclei and occasional binucleated cells. Mitoses are absent. • Grade II (Moderately Differentiated): Lesions are more cellular and have less matrix than grade I tumors. Chondrocyte nuclei are enlarged and hyperchromatic, and often demonstrate greater than one cell in a lacuna. • Grade III (Poorly Differentiated): Chondrocytes are arranged in chords or clumps with less matrix, irregular vesicular or spindle-shaped nuclei, and diffuse mitoses. About 10% of chondrosarcomas include de-differentiated (high-grade sarcoma adjacent to typical low-grade chondrosarcoma), clear-cell (low-grade malignancy with round cells with abundant clear cytoplasm), mesenchymal (high-grade malignancy with small round blue cells with islands of benign-appearing cartilage), and myxoid chondrosarcoma. Treatment: Wide or radical resection is the mainstay of treatment. Due to cartilage being relatively avascular, cells survive transplantation easily allowing for local recurrence after intraoperative tumor contamination. Thus, care must be taken with resection. Wide resection without biopsy may be indicated to decrease the chance of tumor contamination. Chemotherapy has no role in the treatment of conventional chondrosarcoma. Radiotherapy efficacy is limited and is used only as a palliative measure for unresectable lesions. Prognosis: The prognosis of patients with chondrosarcoma depends on the size, location, and histologic grade of the lesion. Low-grade lesions have an approximately 90% 10-year survival rate, compared with a 20% to 40% 10-year survival rate with a high-grade conventional chondrosarcoma.
Definition: Chondrosarcoma is a malignant cartilaginous group of tumors with highly diverse features and behavior patterns that characteristically produce cartilage matrix from neoplastic tissue devoid of osteoid in which ossification, calcification, and myxoid changes can occur. Incidence: Accounts for approximately 20% of all malignant bone tumors and is second only to osteosarcoma in frequency as a primary malignant bone tumor. Peak incidence for primary or central chondrosarcomas arising de novo are between 40 and 60 years of age and between 25 and 45 years of age for secondary or peripheral chondrosarcomas, most often from preexisting benign cartilage lesions such as solitary osteochondromas, enchondromatosis syndromes (Ollier’s disease, Maffucci’s syndrome, metachondromatosis), or multiple hereditary exostoses. About 90% of all chondrosarcomas are conventional chondrosarcomas and 10% are subtypes: de-differentiated, clear-cell, mesenchymal, and myxoid. The tumors are predominantly axial, most commonly involving the pelvis, proximal femur, and proximal humerus, with the metaphysis being the most common location of long bones. There is a slight male predominance but no racial predilection. Clinical: The most common symptom at presentation is pain, which is often dull in character and present for months. Rarely, a palpable mass is present. Diagnostic Studies: Radiography is essential for the initial diagnosis with the radiographic appearance of the chondrosarcoma frequently being diagnostic. X-ray findings demonstrate a lucent lesion frequently containing a pattern of calcification described as punctuate, popcorn, or comma-shaped. There is often an aggressive appearance with cortical destruction, periosteal reaction, and an occasional soft tissue mass. Computed tomography can be helpful in identifying matrix calcifications, endosteal scalloping, and cortical destruction and as a guide in percutaneous biopsies. Magnetic resonance imaging is best for clarifying extraosseous and intramedullary tumor extension.
Fig. 49-1 De-differentiated chondrosarcoma. AP radiograph of the left femur showing a proximal femoral chondrosarcoma with an adjacent area of lytic destruction and pathologic fracture, due to associated de-differentiation to malignant fibrous histiocytoma. (From Adam A, et al: Grainger & Allison’s Diagnostic Radiology, 5th ed. Churchill Livingstone, 2008.)
100
Chondrosarcoma
• 101
Fig. 49-2 Myxoid chondrosarcoma. Lateral radiograph of the femur showing a grade II myxoid chondrosarcoma. Bone expansion indicates a more aggressive behavior. (From Adam A, et al: Grainger & Allison’s Diagnostic Radiology, Philadelphia, Churchill Livingstone, 2008.)
Histology: On gross examination, conventional chondrosarcomas appear smooth, hard, and lobulated. Microscopically, they are again lobulated, showing increased cellularity with hyperchromatic and pleomorphic binucleated or multinucleated malignant chondrocytes. Microscopic grading of conventional chondrosarcoma has prognostic value and is differentiated as follows: • Grade I (Well Differentiated): Lesions have chondrocytes with small, round nuclei and occasional binucleated cells. Mitoses are absent. • Grade II (Moderately Differentiated): Lesions are more cellular and have less matrix than grade I tumors. Chondrocyte nuclei are enlarged and hyperchromatic, and often demonstrate greater than one cell in a lacuna. • Grade III (Poorly Differentiated): Chondrocytes are arranged in chords or clumps with less matrix, irregular vesicular or spindle-shaped nuclei, and diffuse mitoses. About 10% of chondrosarcomas include de-differentiated (high-grade sarcoma adjacent to typical low-grade chondrosarcoma), clear-cell (low-grade malignancy with round cells with abundant clear cytoplasm), mesenchymal (high-grade malignancy with small round blue cells with islands of benign-appearing cartilage), and myxoid chondrosarcoma. Treatment: Wide or radical resection is the mainstay of treatment. Due to cartilage being relatively avascular, cells survive transplantation easily allowing for local recurrence after intraoperative tumor contamination. Thus, care must be taken with resection. Wide resection without biopsy may be indicated to decrease the chance of tumor contamination. Chemotherapy has no role in the treatment of conventional chondrosarcoma. Radiotherapy efficacy is limited and is used only as a palliative measure for unresectable lesions. Prognosis: The prognosis of patients with chondrosarcoma depends on the size, location, and histologic grade of the lesion. Low-grade lesions have an approximately 90% 10-year survival rate, compared with a 20% to 40% 10-year survival rate with a high-grade conventional chondrosarcoma.