Extra-skeletal osteosarcoma: a review

Extra-Skeletal Osteosarcoma of the Prostate After Treated Prostatic Acinar Adenocarcinoma: A Case Report and Review of the Literature

Extra-skeletal osteosarcoma is a rare form of malignant soft tissue sarcoma. Its occurrence in the prostate gland is particularly uncommon. In this case report, we present a patient diagnosed with osteosarcoma arising within the prostatic gland. A 58-year-old man was initially diagnosed with Gleason 8 prostate acinar adenocarcinoma following a transurethral resection (TUR) of the prostate. This diagnosis was accompanied by locoregional involvement and multiple bone metastases. The patient underwent a treatment regimen including complete androgen blockade, chemotherapy, greenlight laser prostate vaporization, and palliative radiotherapy. After treatment, he achieved a complete biochemical response, and his bone metastases remained stable. However, at 16 months post-diagnosis, clinical follow-up by means of radiological examinations revealed an increase in the size of the prostatic lesion, along with additional infiltration of the tumor into the rectum and bladder walls. Remarkably, a mesenchymal tumor proliferation with intratumor calcifications was observed. A subsequent TUR biopsy of the prostate showed a malignant tumor spindle and ovoid cell proliferation with high-grade nuclear atypia, necrosis, and islets of osteoid formation, leading to a final diagnosis of high-grade prostatic extra-skeletal osteosarcoma. Despite undergoing chemotherapy, the patient's condition progressed with the development of pulmonary and liver metastases, culminating in his demise.

Primary osteosarcoma of the kidney: A case report

Primary renal osteosarcoma is an exceedingly rare subtype of renal malignancy, noted for its aggressive nature and often fatal outcome. The scarcity and severity of this condition have resulted in a dearth of reliable methods for early diagnosis and effective treatment. The present article contributes to the existing body of knowledge by presenting a comprehensive clinical case of a 46-year-old male patient with primary renal osteosarcoma. The detailed analysis of the clinical features, imaging characteristics, treatment approaches and prognosis of the patient in the present case aimed to enhance the understanding of renal osteosarcoma and inform clinical decision-making. The patient initially presented with painless hematuria, and further diagnostic work-up, including imaging and pathology, confirmed the diagnosis of primary renal osteosarcoma.

Predicting the Malignancy Grade of Soft Tissue Sarcomas on MRI Using Conventional Image Reading and Radiomics

Objectives: This study aims to investigate MRI features predicting the grade of STS malignancy using conventional image reading and radiomics. Methods: Pretherapeutic imaging data regarding size, tissue heterogeneity, peritumoral changes, necrosis, hemorrhage, and cystic degeneration were evaluated in conventional image reading. Furthermore, the tumors' apparent diffusion coefficient (ADC) values and radiomics features were extracted and analyzed. A random forest machine learning algorithm was trained and evaluated based on the extracted features. Results: A total of 139 STS cases were included in this study. The mean tumor ADC and the ratio between tumor ADC to healthy muscle ADC were significantly lower in high-grade tumors (p = 0.001 and 0.005, respectively). Peritumoral edema (p < 0.001) and peritumoral contrast enhancement (p < 0.001) were significantly more extensive in high-grade tumors. Tumor heterogeneity was significantly increased in high-grade sarcomas, particularly in T2w- and contrast-enhanced sequences using conventional image reading (p < 0.001) as well as in the radiomics analysis (p < 0.001). Our trained random forest machine learning model predicted high-grade status with an area under the curve (AUC) of 0.97 and an F1 score of 0.93. Biopsy-underestimated tumors exhibited differences in tumor heterogeneity and peritumoral changes. Conclusions: Tumor heterogeneity is a key characteristic of high-grade STSs, which is discernible through conventional imaging reading and radiomics analysis. Higher STS grades are also associated with low ADC values, peritumoral edema, and peritumoral contrast enhancement.