By: Terry R. Yochum, DC, DACBR, Fellow, ACCR and Chad J. Maola, DC
This 10-year-old male soccer player complaining of knee pain and shin splints was taken to his family medical doctor by his mother. She was told he needed no X-rays (since there had been no trauma) and was diagnosed with “growing pains.” He was then taken to his mother’s Chiropractor for a second opinion, where he was X-rayed. What do you see?
A densely sclerotic osteosarcoma within the distal metaphysis of the distal femur is present. Note the spiculated (sunburst) periosteal response and a break in the cortex with a soft tissue mass. Growing pains is not a clinical diagnosis, and an error in judgment was made in this case.
- A primary malignant tumor of undifferentiated connective tissue, which forms neoplastic osteoid.1,2
- The second most common primary malignant bone tumor, representing 20% of all primary malignant bone tumors.
- It is twice as common as chondrosarcoma, three times more frequent than Ewing’s sarcoma.1,2
- 75% of cases occur in the 10- to 25-year age range, with a 2:1 male predominance.
- Painful swelling of the involved limb is a common presenting symptom.
- The metaphyses of the distal femur, proximal tibia, and proximal humerus are the most common sites.
- Only 3.5–7% of cases occur within the spine.
- Elevation of serum alkaline phosphatase is the only consistent laboratory finding.1,2
- Three basic patterns exist: 50% of cases are sclerotic, 25% are purely lytic, and 25% are mixed lesions.
- Metastases to the lungs by the hematogenous route are common; the multiple lesions are called cannonball metastases. Spontaneous pneumothorax is a common initial clinical presentation.
- Skeletal metastases occur, but not as frequently as in Ewing’s sarcoma.1,2
- The classic lesion presents as a permeative or ivory medullary lesion in the metaphysis of a long tubular bone.
- A sunburst or sunray periosteal response is characteristic.
- Often, Codman’s reactive triangle is found associated with the destructive lesion.
- Cortical disruption with soft tissue mass formation, often growing to large dimensions, occurs. The peripheral edge of an eccentric lobulated mass whose margins are roughened and irregular may be referred to as the cumulus cloud appearance.1,2
Treatment and Prognosis
- A 20% 5-year survival rate has been traditional; studies using intensive chemotherapy report an 80% survival rate.
- Amputation has offered the best treatment when the lesion is surgically accessible.1,2
- Yochum TR, Rowe LJ. Essentials of Skeletal Radiology, 3rd ed. Baltimore: Williams & Wilkins, 2004:1190.
- Widhe B, Widhe T. Initial symptoms and clinical features in osteosarcoma and Ewing’s sarcoma. J Bone Joint Surg (AM) 2000; 82:667.
About the Authors
Dr. Terry R. Yochum is a second generation Chiropractor and a cum laude graduate of the National College of Chiropractic, where he subsequently completed his radiology specialty. He is a Diplomate of the American Chiropractic Board of Radiology and served as its vice-president and president for seven years (1983-1990).
Dr. Chad J. Maola is a 1999 magna cum laude graduate of National College of Chiropractic.