Common musculoskeletal tumors of childhood and adolescence

Abstract

Osteosarcoma, Ewing sarcoma, and rhabdomyosarcoma are the most common malignant musculoskeletal tumors in children and adolescents. Today, most patients can be cured. Numerous factors have contributed to improved outcome for these patients over the past several decades. These include multidisciplinary care involving oncologists, radiation oncologists, surgeons, pathologists, and radiologists and enrollment of patients in clinical trials. Better understanding of molecular mechanisms of disease have resulted in studies using molecular targets in addition to standard chemotherapeutic agents, which hopefully will lead to better outcomes in the future. Moreover, new orthopedic techniques and devices as well as new technologies in radiation oncology hold promise for better local control of primary tumors and the potential for fewer late adverse effects. Despite this progress, patients must undergo lifelong follow-up for possible late effects of intense chemotherapy and radiation therapy. We review the diagnosis, prognosis, staging, multidisciplinary therapy, new directions in therapy, and long-term complications of treatment for these tumors. For this review, we searched MEDLINE using the terms rhabdomyosarcoma, osteosarcoma, Ewing sarcoma, biology, and humans and limited the search to articles from 2000 to September 2011. Additional references found in these articles were utilized as appropriate, as well as references from the background information in current therapeutic studies of the Children's Oncology Group. The same database and time frame were searched for articles written by leading authorities in the field.

FIGURE 1

Top, Photomicrograph of osteosarcoma showing production of lacelike neoplastic osteoid by hyperchromatic spindle cells. Bottom, Photomicrograph of Ewing sarcoma/primitive neuroectodermal tumor consisting of a sheetlike proliferation of uniform, undifferentiated small round blue cells. Hematoxylin and eosin, magnification 200x.

FIGURE 2

Top, Photomicrograph of embryonal rhabdomyosarcoma, a spindle cell sarcoma, showing a variable degree of rhabdomyoblastic differentiation in the form of “strap cells” and rounded rhabdomyoblasts. Bottom, Photomicrograph of alveolar rhabdomyosarcoma, a small blue round cell tumor with very limited rhabdomyoblastic differentiation, usually in the form of multinucleated giant cells and occasional cells with brightly eosinophilic cytoplasm. Hematoxylin and eosin, magnification 200x.

FIGURE 3

Left, Anteroposterior radiograph of osteosarcoma of the distal femur showing a destructive lesion in the metadiaphysis with neoplastic osteoid formation within the associated soft tissue mass. Middle and Right, Coronal T1- and T2-weighted magnetic resonance images demonstrate the anatomic extent of marrow involvement and soft tissue mass.

FIGURE 4

Left, Anteroposterior radiograph of Ewing sarcoma of the proximal humerus demonstrates a large permeative destructive lesion involving the metadiaphysis with extensive associated malignant periosteal new bone formation and large soft tissue mass laterally. Middle and Right, Coronal T1- and T2-weighted magnetic resonance images show the anatomic extent of the soft tissue mass and marrow infiltration.

FIGURE 5

Expandable prosthesis to maintain limb length in a growing child. Left, Radiograph obtained on presentation of a 10-year-old child with a proximal femur osteosarcoma. Right, Radiograph at 4-year follow-up shows maintenance of equal leg lengths with the use of an expandable prosthesis.