Objective: Although sarcopenia is associated with poor prognosis for cancer patients, the relationship between muscle quantity and quality, and prognosis of breast cancer patients with bone metastases is unclear. This study aims to evaluate the association of muscle parameters, muscle area and density, and overall survival (OS) from the diagnosis of bone metastases in breast cancer patients with bone metastases. Methods: This study retrospectively investigated the prognostic value of muscle area and density in 90 women who were diagnosed with breast cancer with bone metastases between September 2005 and June 2018. We measured psoas major muscle and paravertebral muscle area and density on single axial computed tomography images at the L3 level and subgrouped the patients into higher or lower groups for each muscle measurement, using median values as cutoffs. We evaluated associations between OS and muscle parameters, using a Cox proportional hazards model adjusted by age and prognostic score for bone metastases (modified Katagiri score). Results: Median OS among patients with lower psoas major muscle density (25 months) was significantly shorter than in the higher psoas major muscle density group (61 months; hazard ratio: 1.79, 95% confidence interval: 1.01–3.16, P = 0.045). However, muscle area and paravertebral muscle density were not associated with OS in this setting. Conclusion: Lower psoas major muscle density was a predictor of poor prognosis in patients with breast cancer metastases to bone. The association between psoas major muscle density and prognosis allows wider research into interventions that can prevent loss of muscle density.

Background/Objective: Anti-tumor effects of plasma-activated medium (PAM) were demonstrated using various malignant tumors. However, the anti-tumor effect of PAM on synovial sarcoma remains unclear. Therefore, we aimed to investigate the anti-tumor effects of PAM on synovial sarcoma and its underlying mechanisms, focusing on the quantitative analyses of both intracellular reactive oxygen species (ROS) and cell apoptosis. Methods: The human synovial sarcoma cell line HS-SY-II was used to investigate the cell viability after PAM treatment. We investigated the anti-tumor effects and side effects of local PAM injection in a synovial sarcoma xenograft murine model. Moreover, we observed PAM-induced intracellular ROS accumulation and cell apoptosis and assessed the involvement of intracellular ROS in the anti-tumor effects of PAM using an intracellular ROS scavenger. Results: PAM significantly decreased the viability of synovial sarcoma cells compared with untreated Dulbecco’s modified Eagle medium. Local PAM injection into a synovial sarcoma xenograft murine model significantly suppressed tumor growth, including tumor volume (p < 0.001) and weight (p = 0.031), without side effects. Regarding anti-tumor mechanisms, PAM induced significant cell apoptosis and intracellular ROS accumulation (p < 0.001). The intracellular ROS scavenger significantly inhibited the anti-tumor effect of PAM (p < 0.001). Conclusions: We confirmed the anti-tumor effects of PAM on synovial sarcoma in vitro and in vivo, as well as the absence of side effects. The underlying mechanism was suggested to involve cell apoptosis induced by intracellular ROS accumulation. Considering the various clinical issues associated with the existing treatments of synovial sarcoma, PAM is a promising new option.

Hamate hook fractures are usually caused by direct trauma while using a tennis racket or a baseball bat. We report stress fracture of the hamate hook in a water polo player without any specific trauma. We consider that the stress fracture occurred via indirect mechanisms through the flexor tendons. Strong ulnar deviation of the wrist during ball release and strong grip on a ball with outstretched fingers, which are unique to water polo, were the likely causes of the stress fracture of the hamate hook.

Rotationplasty is a useful option for limb salvage surgery in pediatric patients with malignant bone and soft tissue tumors. However, bone growth after rotationplasty remains poorly characterized. We present a case of a 3-year-old boy with extraskeletal Ewing sarcoma who underwent multidrug chemotherapy (vincristine, doxorubicin, ifosfamide and etoposide), wide resection and functional reconstruction with rotationplasty. No radiotherapy was administered during the treatment course and the patient has been followed up for 16 years after rotationplasty. Leg length at skeletal maturity was predicted using postoperative radiograph measurements of the affected leg at the age of 4 years. Two conventional prediction methods, the multiplier and straight-line graph methods were used for prediction. The predicted leg length was compared with the actual leg length to assess bone growth after rotationplasty. Immediately after surgery, the lengths of the affected lower leg, femur and tibia were 32.5, 15.0 and 17.6 cm, respectively, and the predicted leg length of the affected leg at skeletal maturity using the multiplier and straight-line graph methods was 44.6 and 44.2 cm, respectively. However, the actual length of the affected leg at skeletal maturity was 49.8 cm, and the gap between actual and predicted lengths was more than 5 cm. In conclusion, the affected leg after rotationplasty showed more than expected bone overgrowth compared with the predictions of the conventional methods.

Introduction and importance: Pseudomyogenic hemangioendothelioma (PMHE) is a rarely metastasizing intermediate endothelial neoplasm. It typically presents as multiple, discontinuous nodules in the lower extremities of young adult males. Most cases present skin or soft-tissue tumors, but intraosseous lesions without soft-tissue involvement are extremely rare. We report a case of PMHE of the tibia, diagnosed with FOSB staining. Presentation of case: A 36-year-old man presented with pain in the lower left leg after exercise and at night. X-ray, SPECT/CT, and MRI revealed two discontinuous lytic lesions within the cortical bone of the left tibia. A curettage procedure was performed for biopsy, but a diagnosis could not be made for a long time. After further consultation, FOSB staining was positive in the nucleus, leading to a definitive diagnosis of PMHE. No recurrence or metastasis was observed 2 years after surgery. Clinical discussion: PMHE is a rare endothelial tumor, and cases limited to bone without soft tissue involvement are exceptional. Diagnosis is difficult because of overlap with myogenic and epithelioid tumors, but nuclear FOSB staining is a reliable marker. Although local recurrence is frequent, metastasis is rare, underscoring the importance of accurate diagnosis and long-term follow-up. Conclusion: This case highlights the importance of considering PMHE in the differential diagnosis of bone tumors, the utility of FOSB immunostaining in confirming the diagnosis, and the need for long-term follow-up given the high risk of local recurrence.