Differential diagnosis:

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Herein listed are available results for your case scenario (Table 6.1):

Osteosarcoma is the most comm on malignant bone tumor in children and adolescents .

The incidence of osteosarcoma is five per million with less new cases reported in the black population. It is more common in older children and young teenagers.

Most patients present during the second and third decades of life, 70–75 % of patients being between the ages of 15 and 25 years.

The bones with a rapid growth such as the distal femur, proximal tibia, and proximal humerus are the most affected.

Risk factors for the development of osteosarcoma include the presence of a germline mutation in the RB1 (bilateral retinoblastoma syndrome) or TP53 genes (Li-Fraumeni syndrome). Survivors of bilateral retinoblastoma are at a significantly increased risk of developing osteosarcoma; this risk is augmented if the patient has received radiation therapy. Patients with Rothmund-Thomson syndrome have also a high chance of apparition of this bone tumor.

The modern treatment consists in chemotherapy and surgery and the cure rate reaches now more than 70 %. The advanced forms with lung metastases have a poor prognosis.

There are very few reports regarding osteosarcoma in Africa as the incidence is not known. It is postulated that osteosarcoma is rarer in black children than in the white population.

Most patients present late with disseminated disease and their prognostic remains reserved. The lack of specialized units and orthopedic surgeons contribute to the challenges of the disease.

The clinical picture of the disease is dominated by pain , which is present in more than 90 % of the patients. The pain is persistent with exacerbation during the night and is not responding to pain medication. The pain also occurs at rest and may be associated with constitutional symptoms such as weight loss, pallor, and anorexia. The pain is related to the tumor itself but can also be caused by nerve or vascular compression depending on the site. The pain is associated in majority of the cases with impressive swelling. The symptoms are usually present for several weeks before the presentation to the clinic or to the general doctor.

On rare occasions a pathological fracture can be associated with the tumor, following a minor trauma.

Most African patients with osteosarcoma present with advanced disease. At presentation, a limp or loss of function and/or decreased range of motion may be detected.

The most common sign is a mass that is invariable firm and tender.

Lesions are typically located in the metaphyseal region of long bones, with the distal femur and proximal tibia making up approximately 50 % of all cases.

The diagnosis is based on the suspicion of persistent bone pain associated with a growth in most of the cases. The radiographic changes contribute to the suspicion but the confirmatory diagnosis is based on the pathological examination of the tissue obtained during a biopsy.