High-grade surface osteosarcoma of the hand.

Area of Science:

• Orthopedic Oncology
• Skeletal Radiology
• Surgical Pathology

Background:

• Bone- and cartilage-forming lesions in the hands and feet are typically benign.
• Osteosarcoma, a primary bone cancer, is rare in the short tubular bones of the extremities.

Observation:

• A 32-year-old woman presented with a year of finger pain and a calcified lesion on imaging.
• Radiographs, CT, and MRI showed a lesion with cortical erosion and specific signal characteristics.
• Initial clinical and imaging diagnosis suggested a benign process like florid reactive periostitis.

Findings:

• Histological examination revealed atypical osteoblastic cells and irregular osteoid, indicating high-grade surface osteosarcoma.
• This diagnosis was established despite initial imaging suggesting a benign bone-forming lesion.
• High-grade surface osteosarcoma is an exceptionally rare subtype of osteosarcoma.

Implications:

• This case highlights the importance of considering rare malignancies in the differential diagnosis of hand and foot bone lesions.
• Atypical radiological or clinical findings warrant thorough pathological investigation to avoid misdiagnosis.
• Accurate diagnosis is critical for appropriate management and improved patient outcomes in rare bone cancers.