Osteosarcoma is the most common type of primary bone cancer, which usually appears in the distal femur. The diagnosis of this condition typically involves advanced imaging and tissue biopsy, as well as taking into account characteristic clinical and radiographic indicators. The treatment approach for distal femoral osteosarcoma is multidisciplinary and involves initial chemotherapy, followed by limb-sparing surgery, reconstruction of bone and soft tissue, and subsequent adjuvant chemotherapy. We present a case study of a 25-year-old male admitted with a blastic lesion in the distal femur, confirmed via open biopsy to be osteoblastic osteosarcoma. Further evaluation revealed multiple pulmonary nodular lesions, managed with chemotherapy. After four months, regression of the lesion was observed. Due to malignant clinical and imaging features, excision of the lesion and subsequent reconstruction were performed, utilizing a custom-made total knee arthroplasty. The excision encompassed the removal of the distal 14 cm of the femur, with histological examination confirming central osteoblastic osteosarcoma. Satisfactory outcomes were observed during a one-year follow-up, indicating promising results. Vigilance is crucial, especially in young patients with surface-type bone tumors, as this neoplasm requires consideration.

Osteosarcoma is a malignant mesenchymal tumour. This primarily manifests in the formation of immature osteoid cells by tumour cells. Osteosarcoma is the most common primary bone tumour in children and adolescents. It tends to occur in the metaphysis of long shafts, shows osteoblastic differentiation, and produces malignant osteoid material. We present the case of a 17-year-old male who presented to our clinic who had left knee pain for a few days. An initial radiograph of the knee joint revealed a lytic lesion in the proximal tibia and further imaging was advised. During a follow-up visit, the patient had worsening pain and had a computerized tomography scan of the left knee, confirming osteosarcoma on the lateral side of the left tibia. He was referred to the orthopaedic department, where a biopsy was performed, to confirm the diagnosis of osteosarcoma. The patient was commenced on chemotherapy due to metastatic disease and has so far tolerated therapy well.

OBJECTIVE: Emerging evidence suggests that osteosarcoma stem cells (OSCs) may be responsible for tumor initiation propagation, recurrence, and resistance to therapy. We set out to evaluate the relationship between the abundance of ALDH1A1 and CD44-positive cells in biopsy and resection samples on disease recurrence and overall survival.
METHODS: A retrospective review of 20 patients, including biopsy and resection samples, was performed at a comprehensive cancer center. Additionally, we queried the publicly available TARGET dataset of osteosarcoma patients.
RESULTS: Neither the percentages of ALDH1A1-positive cells nor CD44-positive cells were significantly associated with overall mortality or disease recurrence in either biopsy or resection samples. Unlike our institutional data, overall survival was significantly correlated to higher ALDH1A1 expression in the TARGET dataset both in univariate and age-adjusted analyses.
CONCLUSIONS: ADLH1 and CD44, potential markers of OSCs, were not found to be reliable clinical immunohistochemical prognostic markers for osteosarcoma patient survival, specifically disease-free survival. Osteosarcoma patients with high ALDH1A1 RNA expression showed improved overall survival in examining a national genomic database of osteosarcoma patients but again no association with disease-free survival. The potential of CD44 and ALDH1A1 as cellular-specific prognostic markers of survival, and as possible molecular targets, may be limited in osteosarcoma.