May 3

May 3 CASE 124

Nizar Al Nakshabandi

By: Dr. Nizar Al-Nakshabandi MD, FRCPC

Case courtesy of Ciro Duarte

HISTORY: 79-year-old female with swelling in the skull and hemoptysis.

What are your findings?

What is the differential diagnosis?

What are the causes?

FINDINGS:

The sagital reformatted CT scan of the skull [A] demonstrates an aggressive lytic sclerotic lesion arising from the frontal bone of the skull with evidence of extensive sunray Sunburst periosteal reaction on both sides of the calvarial skull with evidence of bony destruction. Sagital T2 of the brain [B] demonstrates the bony tumor arising from the calvarium of the skull with evidence of extra-axial mass effect on the frontal lobe of the bone. Sagital T1 with fat sat and gadolinium administration demonstrate avid enhancement of the bony tumor with direct extension into the frontal bone with enhancement of the frontal lobe of the brain

Transaxial CT scan of the lungs, soft tissue window with IV contrast enhancement demonstrates a calcified metastatic lesion to the left upper lobe of the lung.

DIFFERENTIAL DIAGNOSIS:

· Osteosarcoma of the skull.

· Chondrosarcoma sarcoma of the frontal bone.

· Metastatic lesion to the skull.

· Fibrosarcoma.

· Chordoma.

DIAGNOSIS:

Osteosarcoma of the skull.

PEARLS AND DISCUSSION:

Osteosarcomas are malignant bone tumors. It commonly affects long bones and young adults. Primary osteogenic sarcoma of skull is a rare entity constituting 2% of all osteogenic sarcomas.

Clinical features are localized pain that frequently begins after an injury and waxes and wanes over time. The most important finding on physical examination is a soft tissue mass, which is frequently large and tender to palpation.

Laboratory evaluation is usually normal, except for elevations in alkaline phosphatase, lactate dehydrogenase, and erythrocyte sedimentation rate.

At the time of presentation, between 10 and 20 percent of patients have demonstrable macrometastatic disease. Such as in our case which is metastatic tumor to the lungs which has calcified. Refer to figure D.

Imaging requires MRI and in this case CT scan to demonstrate the full extent of the osteoid matrix. CT is also important to evaluate the thorax for metastatic disease. Bone scan or PET/CT have a greater utility to assess response for chemotherapy. No radiological finding is pathognomonic. Biopsy is required for definitive diagnosis.

Treatment is usually by surgery and with chemotherapy. Sometimes radio-therapy is required.

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