OSteosarcoma

Osteosarcoma is a primary malignant tumor in which the neoplastic cells produce osteoid matrix. It is the most frequent primary cancer of bone.

Aetiology

The majority arise in adolescence, but some are linked to other pathologies (Paget's disease) occurring in the sixth and seventh decades of life.

Site

Osteosarcoma usually arises in the metaphysis of an extremity long bone, most commonly around the knee though it can occur anywhere in the axial or appendicular skeleton.

Histologic variants

Conventional osteosarcoma, a high grade malignancy, accounts for the majority of osteosarcoma. Other high grade types are telangiectatic, small cell, and high grade surface osteosarcoma. Low grade central and parosteal osteosarcoma are low grade malignancies, while periosteal osteosarcoma is an intermediate-grade osteosarcoma.

Biopsy

- Biopsy diagnosis is mandatory.

- Biopsy to be done only after all local imaging is completed.

- In most cases a core needle biopsy +/- image guidance – depends on the location of the lesion

- Should be done preferably under the guidance of the final operating surgeon

Serological Investigations

Though there are no specific laboratory tests for diagnosis some may be of prognostic value; e.g. alkaline phosphatase (ALP) and lactate dehydrogenase (LDH).

Staging

- Local X-Ray

- MRI

- CT Scan Chest

- Bone Scan or

- FDG / Fluoride PET