High-grade surface osteosarcoma - chondroblastic type

Area of Science:

• Orthopedic Oncology
• Pediatric Oncology
• Skeletal Radiology

Background:

• Chondroblastoma is a rare bone tumor typically presenting as an epiphyseal or apophyseal lesion.
• Aggressive variants and malignant transformation are uncommon but documented complications.
• Early misdiagnosis can lead to delayed treatment and potentially worse outcomes.

Observation:

• An 8-year-old boy presented with thigh pain after trauma, initially suspected as exostosis.
• Histological examination revealed an aggressive chondroblastoma, which recurred as a painful mass post-surgery.
• Radiographic and CT findings indicated a high-grade malignant bone tumor with soft tissue involvement.

Findings:

• The initial chondroblastoma transformed into a high-grade surface osteosarcoma of chondroblastic type.
• Computed tomography proved valuable in identifying signs of high-grade malignancy.
• Despite treatment including chemotherapy and surgery, the patient experienced disease recurrence.

Implications:

• High-grade surface osteosarcoma carries a grave prognosis compared to other surface osteosarcomas.
• Accurate and timely diagnosis is critical for effective management of aggressive bone tumors.
• This case highlights the importance of thorough evaluation for bone lesions, especially after trauma in pediatric patients.