Chapter 36: Sarcomas

Epidemiology

2020 WHO Classification of Malignant Bone Tumors

1. Chondrogenic tumors

   Chondrosarcoma, grades 1

   Chondrosarcoma, grades 2

   Chondrosarcoma, grades 3

   Periosteal chondrosarcoma

   Clear cell chondrosarcoma

   Mesenchymal chondrosarcoma

   Dedifferentiated chondrosarcoma

2. Osteogenic tumors

   Low-grade central osteosarcoma

   Osteosarcoma NOS

     Conventional osteosarcoma

     Telangiectatic osteosarcoma

     Small cell osteosarcoma

   Parosteal osteosarcoma

   Periosteal osteosarcoma

   High-grade surface osteosarcoma

   Secondary osteosarcoma

3. Fibrogenic tumors

   Fibrosarcoma NOS

4. Vascular tumors of bone

   Epithelioid hemangioendothelioma NOS

   Angiosarcoma

5. Osteoclastic giant cell-rich tumors

   Giant cell tumor of bone, malignant

6. Notochordal tumors

   Chordoma NOS

     Chondroid chordoma

   Poorly differentiated chordoma

   Dedifferentiated chordoma

7. Other mesenchymal tumors of bone

   Adamantinoma of long bones

     Dedifferentiated adamantinoma

   Leiomyosarcoma NOS

   Pleomorphic sarcoma, undifferentiated

   Bone metastases

8. Hematopoietic neoplasms of bone

   Plasmacytoma of bone

   Malignant lymphoma, non-Hodgkin, NOS

   Hodgkin disease, NOS

   Diffuse large B-cell lymphoma NOS

   Follicular lymphoma NOS

   Marginal zone B-cell lymphoma NOS

   T-cell lymphoma NOS

   Anaplastic large cell lymphoma NOS

   Malignant lymphoma, lymphoblastic, NOS

   Burkitt lymphoma NOS

   Langerhans cell histiocytosis NOS

   Langerhans cell histiocytosis, disseminated

   Erdheim-Chester disease

   Rosai-Dorfman disease

Adapted from: Choi JH, Ro JY. Adv Anat Pathol 2021;28:119–138. (note: non-malignant tumors have been omitted from this list)

Work-up

1. History and physical examination

2. Laboratory tests: CBC with differential; electrolytes including calcium, phosphorus, and magnesium; renal function tests including blood urea nitrogen (BUN) and creatinine; liver function tests including liver enzymes and total bilirubin; alkaline phosphatase; lactate dehydrogenase

3. Plain films of affected bone

4. CT scan of chest, abdomen, and pelvis (particularly chest because 80% of metastatic lesions occur here). CT scan may be performed in conjunction with FDG-PET. High resolution chest CT scan should be performed

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

6. Technetium-99 bone scan to identify skip lesions within affected bones or distant metastatic disease

7. Whole body 18-fluoro-deoxyglucose positron emission tomography (FDG-PET)/CT is more routinely being performed particularly for Ewing sarcoma

8. Bilateral bone marrow aspirate and biopsy 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

12. Fertility preservation to be offered when feasible

Surgical Staging