Orthopaedic Nurses Certification Board (ONCB) Metabolic/Inflammatory/Tumors Practice Exam

What is the most common primary malignant bone tumor in children?

1. Hemangioma

2. Mesenchymal chondrosarcoma

3. Osteosarcoma

4. Multiple myeloma

The correct answer is: Osteosarcoma

Osteosarcoma is recognized as the most common primary malignant bone tumor in children. This aggressive cancer typically arises in the long bones, particularly around the knees and shoulders, and is most prevalent in adolescents during their growth spurts. Osteosarcoma is characterized by the production of osteoid, or bone matrix, by the malignant cells, which differentiates it from other types of tumors. The significance of osteosarcoma in pediatric oncology cannot be overstated, as it represents a major focus for research, treatment strategies, and clinical trials. Factors such as the rapid growth rate of bones during childhood and adolescence contribute to the higher incidence of this tumor among younger populations. Other options represent different entities that do not share the same prevalence as osteosarcoma in children. For instance, hemangiomas are vascular tumors that are more common in adults and not classified as malignant bone tumors. Mesenchymal chondrosarcoma is a rare cancer that can occur in both adults and children but is not as frequently diagnosed as osteosarcoma. Multiple myeloma, primarily seen in older adults, originates from plasma cells and is not a primary bone tumor affecting children. Understanding these distinctions highlights why osteosarcoma is the predominant primary malignant bone