Chapter 34: Sarcomas

Primary Malignant Bone Tumors: Epidemiology

Classification: WHO Classification of Malignant Bone Tumors

Osteogenic tumors

Osteosarcoma

1. Conventional

   • Chondroblastic

   • Fibroblastic

   • Osteoblastic

2. Telangiectatic

3. Small cell

4. Low-grade central

5. Secondary

6. Parosteal

7. Periosteal

8. High-grade surface

Ewing sarcoma/primitive neuroectodermal tumor

Ewing sarcoma

Cartilage tumors

Chondrosarcoma

1. Central, primary, and secondary

2. Peripheral

3. Dedifferentiated

4. Mesenchymal

5. Clear cell

Fibrogenic tumors

Fibrosarcoma

Fibrohistiocytic tumors

Malignant fibrous histiocytoma

Giant cell tumor

Malignancy in giant cell tumor

Notochordal tumors

Chordoma

Vascular tumors

Angiosarcoma

Smooth muscle tumors

Leiomyosarcoma

Lipogenic tumors

Liposarcoma

Miscellaneous tumors

Adamantinoma

Hematopoietic tumors (see respective sections)

1. Plasma cell myeloma

2. Malignant lymphoma, NOS

Work-up

1. History and physical examination

2. Laboratory tests: CBC with differential; electrolytes; liver function tests; mineral panel, including alkaline phosphatase; lactate dehydrogenase

3. Plain films of affected bone

4. Chest x-ray (PA and lateral)

5. CT scan of chest, abdomen, and pelvis (particularly chest because 80% of metastatic lesions occur here)

6. MRI to ascertain extent of the tumor, involvement of surrounding neurovascular structures, invasion of the adjacent joint, and the presence of skip metastases

7. Bone scan to identify skip lesions within affected bones or distant metastatic disease

8. Bone marrow aspirate for light microscopy examination in the case of Ewing sarcoma

9. No radiologic studies are pathognomonic, so bone biopsy remains essential to diagnosis

10. Echocardiogram or MUGA scan to determine cardiac ejection fraction as clinically indicated

11. Audiogram before cisplatin chemotherapy

Surgical Staging