Cytologically Yours: CoW: 20140206

Clinical Summary

The patient is a 12 year old female with a six month history of left shoulder pain. The patient had tried Aleve and had several chiropractic visits which were unsuccessful at relieving the pain.

Past Medical History

• Previously heathy

Past Surgical History

• No surgical history

Radiology

• AP/Lateral images show a destructive and aggressive appearing lesion in the left proximal huerus in the metaphysis extending 7.5cm distally in the diaphysis.

Clinical Plan

The differential diagnosis included osteosarcoma and Ewing sarcoma. MRI and CT guided biopsy are scheduled.

Pathology

Cytology

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  40x magnification of highly atypical malignant appearing cells.

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  20x magnification showing osteoid formation.

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  40x magnification showing osteoid formation and malignant appearing cells.

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  40x magnification of osteoid.

Resident Questions

• The radiologic differential diagnosis was between osteosarcoma and Ewing sarcma. What would be a possible diagnostic pitfall?

The confusion between osteosarcoma and Ewing may occur with the small cell variant of osteosarcoma.   

Click here to toggle the diagnosis and discussion.

Final Diagnosis

Cytology

• High grade sarcoma, favor osteosarcoma.

Biopsy

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  20x magnification of bone biopsy showing sclerotic bone.

Biopsy Diagnosis

• Conventional high grade sarcoma, sclerotic type.

Discussion

The experience of FNA of osteosarcoma is mainly with conventional high-grade intramedullary sarcoma and to the rare high-grade surface osteosarcoma. Smears usually contain dissociated neoplastic cells and cell clusters.