Osteosarcoma is a rare tumor diagnosed at any age; however younger age is a common risk factor. In addition, multiple factors are believed to contribute to higher rates of osteosarcoma, particularly race and gender. Although diagnosed worldwide, osteosarcoma is found to be more prevalent in Africa with high numbers of cases reported in Nigeria, Uganda, and Sudan. Additionally, higher rates are detected in African Americans, suggesting a genetic predisposition linked to race. This review focuses on identifying high risk factors of osteosarcoma with an emphasis on sarcoma epidemiology and risk factors in African countries.

The purpose — to assess the lesions of joints and periarticular tissues in patients with inflammatory bowel diseases (IBD) and their correlation with IBD course. Material and methods. The research included 50 patients with IBD. Clinical and ultrasound examinations of peripheral joints and sinew and ligaments entheses in the joint projections were performed. Analysis of the correlation between the clinical characteristics of IBD (course and duration of the disease) and signs of joint and entheses damage (joint pain, number of tender entheses, synovitis, enthesitis, LEI, MASES, SPARCC, GUESS, MASEI, BUSES indices) was performed with Spearman criteria. Results. IBD duration had a direct correlation with the presence of joint pain (SR = 0.58; р = 0,0006), number of tender entheses (SR = 0,47; р = 0,008), and number of enthesitis (SR = 0,4; р = 0,002). The disease duration also directly correlated with the GUESS (SR = 0,38; р = 0,034). There was no statistically significant relationship between the attack severity and the damage to the joints and entheses. Conclusion. The frequency of joint and periarticular tissues damage (pain, tender enthuses during palpation, enthesitis without vascularization, ultrasound index of enthuses lesions GUESS) is significantly correlated with the duration of the disease. Manifestations of the joint and periarticular tissues lesions are independent of IBD activity.