Presentation
8 month history of leg pain and swelling below the knee. Patient presented after her mother noticed a visible leg mass.
Patient Data
A poorly defined sclerotic lesion in the proximal tibia with "sunburst" periosteal reaction and Codman's triangle. Findings are suggestive of osteosarcoma.
HISTOLOGY
Macroscopic description: The specimen is a right tibia core biopsy. Multiple white tan cores of friable tissue, all measuring less than 0.1 cm in diameter and ranging from 0.1 cm to 1.2 cm in length.
Microscopic description: Only scan osteoid is present. The specimen comprises 90% high grade malignant cartilage.
Diagnosis: High grade sarcoma, predominantly chondroblastic, most consistent with high grade chondroblastic osteosarcoma.
Case Discussion
Osteosarcoma is the most common type of bone tumor in children and typically occurs at the metadiaphyses of long bones. Common locations include the femur, tibia and humerus. Of the histologic subtypes, osteoblastic osteosarcoma ocurrs most often. This patient underwent CT-guided core biopsy and pathology confirmed a diagnosis of chondroblastic osteosarcoma. The histologic subtype has important implications for patient treatment and survival 1.