The symptoms of osteosarcoma may not be obvious in the beginning and, as a result, the initial diagnosis of the disease can often occur after it has already developed significantly. In fact, the first time that many individuals notice a sign of the disease is when the suddenly fracture the affected after minor trauma, as a result of the weakened bone.
There are, however, some signs that may be evident and if it is possible to recognize these earlier, timely treatment can be begun earlier to improve prognosis and avoid a fracture.
When the disease is suspected, several imaging techniques that may be used to investigate the structure of the bone and a possible tumor inside. A biopsy of the tumor is then needed to confirm the malignancy of the tumor and the appropriate treatment.
Pain is a symptom of osteosarcoma that many patients notice. Particularly teenagers who participate in sporting activities tend to complain about pain below the knee, or in their lower femur. It is common for this pain to worsen during the nighttime, but it is normal for it to vary in intensity and come and go over time.
Swelling in the area may also become evident, especially if the tumor has grown to a large size. However, even a big tumor may not produce visible swelling if it is not near the surface of the body. An example of this is a tumor on the pelvis, which is more difficult to detect.
The bones affected by osteosarcoma are not as strong as healthy bones. This is not often visible or identifiable by patients, but they will be more likely to fracture the bone as a result. This can occur even with minor trauma, known as a pathological fracture.
Most tumors of the bone are benign, however, adequate imaging needs to be done to accurately diagnose the condition.
An X-ray is the first type of imaging that needs to be done, which is then followed by a number of different scans. This includes:
- CT scan
- PET scan
- Bone scan
It is characteristic to see Codman’s triangle in the X-ray image, with is a subperiosteal lesion formed when the tumor causes the periosteum to rise. Additionally, it is possible for the tumor to metastasize to the lungs, which will appear on the X-ray image. It usually presents as nodule on the lower part of the lung.
The final step to confirm the diagnosis of osteosarcoma is to take a surgical biopsy. This enables physicians to test the tumor cells for malignancy and helps to guide future treatment.
The images and scans are an effective way to understand the nature of the tumor, but the only definitive way to determine if the tumor is malignant or benign is to take a bone biopsy.
A qualified orthopedic oncologist should conduct this process, as it is of utmost importance that is carried out correctly. If it is not performed properly, it may be difficult to salvage the affected limb and avoid amputation.
There are several different variants of osteosarcoma. Once diagnosis has been confirmed, the disease is usually categorized as:
- Conventional (e.g. osteoblastic, chondroblastic, fibroblastic)
- Small cell
- Low-grade central
- High-grade surface
- Extraskeletal This describes the types of cells affected and can help with the treatment decisions of the condition.