CASE 11
By: Dr. Saleh Othman, MD, MSc, JMCB
HISTORY: 12-year-old male patient with left leg pain of
4 months duration. Left femur radiograph revealed features of Ewing’s sarcoma.
What are your findings?
What is you’re your differential diagnosis?
What are the pathophysioloy of the disease?
FINDINGS:
Focal area of increased uptake in mid shaft of left femur with soft tissue component matching with radiographic abnormalities of Ewing’s sarcoma. There was no evidence of distant bone metastases.
DIAGNOSIS:
Ewing’s sarcoma.
PEARLS AND DISCUSSION:
Ewing’s sarcoma is a malignant bone tumor which has a peak incidence in the first and second decades. The tumor arises from the bone marrow. Clinically presents with symptoms and signs of osteomyelitis (pain, fever and leukocytosis). The tumor affects long bones especially femur and tibia. On bone scan it shows increased uptake on delayed images. The incidence of distant bone metastases is about 60%.
The other primary malignant bone tumors show variable increased blood flow and blood pool but all show increased delayed uptake.
Teaching points:
The primary imaging modality in malignant primary bone tumors is radiograph, CT and MRI.
In Ewing’s sarcoma the lesion usually produces a "moth-eaten" pattern of bone destruction on plain film radiographs.
Ewing’s sarcoma is typically “hot” on blood pool and delayed bone scan images.
Although bone scan is sensitive for lesion detection in Ewing’s sarcoma, scan appearances are non-specific.
Bone scan primary malignant tumors is used to determine disease extent and for therapy planning.
FURTHER READING:
Radiol Clin North Am 1993; Brown ML. Bone scintigraphy in benign and malignant tumors. 31(4):731-8. Review.
Radiographics 2013; Murphey MD, et al. From the radiologic pathology archives. Ewing sarcoma family of tumors: radiologic-pathologic correlation. 33: 803-831
