Intraosseous Well-differentiated Osteosarcoma

Summary
Description

Low Grade Osteosarcoma accounts for 1-2% of osteosarcomas. This intraosseus tumor occurs in the metaphysis and diaphysis of the distal femur or proximal tibia.

People and Age
It often occurs in the older patient population.
Symptoms and Presentation
Low Grade Osteosarcoma generally presents itself as a pathologic fracture.
Brief description of the xray
On plain x-ray, low grade osteosarcoma may appear as osteolytic, ground glass, or sclerotic.
Tumor Type
Benign or Malignant
Most Common Bones
Location in bone
Complete Information on this Tumor
Introduction and Definition

Low Grade Osteosarcoma accounts for 1-2% of osteosarcomas. This intraosseus tumor occurs in the metaphysis and diaphysis of the distal femur or proximal tibia.

Incidence and Demographics
This type of tumor is generally uncommon and is generally found in the older patient population.
Symptoms and Presentation

Low-grade Osteosarcoma's often present themselves as pathologic fractures.

X-Ray Appearance and Advanced Imaging Findings
On plain x-ray, low grade osteosarcoma may appear as osteolytic, ground glass, or sclerotic. The bone destruction is regular and expansive which often contributes to a misdiagnosis as benign. This slow growing tumor has poorly defined margins.
Histopathology findings
Low grade osteosarcoma is normally a grade 1 tumor histologically. There is a large amount of collagen surrounding the occasional spindle cells. Some authors believe this tumor is a relative of parosteal osteosarcoma as they both have a similar microscopic appearance and low malignant potential.
Treatment Options for this Tumor
Like parosteal osteosarcoma, low grade osteosarcoma has a good prognosis. Treatment is surgical excision and is not followed by chemotherapy.
Outcomes of Treatment and Prognosis
Suggested Reading and Reference
Bloem, JL and HM Kroon, Osseous Lesions, Radiologic Clinics of North America, 31(2):261-277, March, 1993.

Bullough, Peter, Orthopaedic Pathology (third edition), Times Mirror International Publishers Limited, London, 1997.

Huvos, Andrew, Bone Tumors: Diagnosis. Treatment and Prognosis, W.B. Saunders, Co., 1991.