Background: The spread of coronavirus disease 2019 (COVID-19) has caused severe damage to routine medical care. This study aimed to investigate the impact of COVID-19 on bone and soft tissue tumor treatment at a single center. Methods: A retrospective comparative study was conducted between two groups of patients who received treatment at Osaka City University Hospital during the peak of the COVID-19 pandemic (February-December 2020, Group C) and during the same period the previous year (February to December 2019, Group NC). Clinical data, including patient's age, sex, tumor site, type of neoplasms, number of surgical cases for inpatients and outpatients, operation time, use of implant, length of hospital stay, inpatient hospitalization costs, number of inpatients receiving anticancer drugs, and postoperative complications in these two groups were retrospectively evaluated. Results: The number of cases of malignant bone and soft tissue tumors that were resected during hospitalization was predominantly higher in Group C than in Group NC ( P =0.01). There were no significant differences in operation time, use of implant, and postoperative complications between Groups C and NC; however, there were significant differences in the length of hospital stay and hospitalization cost ( P <0.001). Conclusions: Globally, COVID-19 has affected several areas adversely. The present study showed that the COVID-19 pandemic had an impact on the hospitalization cost and length of hospital stay during the treatment of bone and soft tissue tumor.

Purpose: The pathogenesis of cystic fluid storage in solitary bone cysts remains unclear. We aimed to compare the results of the biochemical analysis of cystic fluid with clinical findings. We identified a significant marker of postoperative recurrence. Methods: Twenty-seven male and eight female patients were studied; the median age at diagnosis was 11 (5–23) years. The mean follow-up period was 60 months (range: 14–146 months). Clinical information including sex, age, affected site, radiological findings of phase (active or latent), surgical procedure, outcome, and biochemical analysis of serum and cystic fluid was obtained. Results: The 5-year healing rate was 64.0%. Biochemical analysis revealed that total protein and albumin values in the cystic fluid were significantly lower, compared to those in the serum. Levels of bone turnover markers, such as alkaline phosphatase, bone-specific alkaline phosphatase, and tartrate-resistant acid phosphatase 5b were remarkably elevated in the cystic fluid than in the serum. R values were 0.127, 0.076, and 0.095 for alkaline phosphatase, bone-specific alkaline phosphatase, and tartrate-resistant acid phosphatase 5b, respectively. Areas under the receiver operating characteristic curves, calculated to assess the association of alkaline phosphatase, bone-specific alkaline phosphatase, and tartrate-resistant acid phosphatase 5b levels in the cystic fluid with postoperative recurrence, were 0.57, 0.51, and 0.70, respectively. Conclusions: No clear correlation of bone turnover marker levels between the serum and cystic fluid was observed. The high tartrate-resistant acid phosphatase 5b level in the cystic fluid was associated with postoperative recurrence. The bone resorption caused by osteoclasts is considered to affect postoperative recurrence. Level of evidence: Level IV.

Introduction Superficial soft tissue sarcomas are often left untreated unless they invade the skin and skin ulcers manifest. Progressive sarcomas frequently result in dismal oncological outcomes despite multidisciplinary treatment. This study aimed to identify prognostic factors for superficial soft tissue sarcomas. Materials and methods This study retrospectively analyzed the clinicopathological data of 82 patients with superficial soft tissue sarcomas treated between August 2003 and December 2020 at our institution. A superficial soft tissue sarcoma was defined if the percentage of the area occupied by the tumor in the assessed region (skin, subcutaneous) was more than 50%. Age, sex, location, tumor size, tumor-skin invasion, tumor grade, and distant metastasis at initial diagnosis were evaluated as potential prognostic factors. Cox proportional hazards regression models were used to identify the prognostic factors. Five-year survival rates were assessed by the Kaplan-Meier method. Results The mean follow-up time was 60.1 months. The 5-year overall survival, 5-year local recurrence-free survival, and 5-year metastasis survival rates were 76.4%, 60.6%, and 71.0%, respectively. Univariate analysis showed significant relationships between poor prognosis and tumor size ≥5 cm, distant metastasis at initial diagnosis, and tumor-skin invasion. In the multivariate analysis, only the tumor-skin invasion was associated with worse overall survival. Conclusions Superficial soft tissue sarcomas have biologically been considered a separate category due to their better prognosis. In this study, the tumor-skin invasion was the only significant factor associated with a poor prognosis. Therefore, all superficial soft tissue sarcomas without tumor-skin invasion should be treated as early as possible.

Background Soft tissue tumors are often accompanied with elevated skin temperature; however, studies concerning the relationship between soft-tissue tumors and skin temperature elevation are scarce. We aimed to evaluate the clinical significance of skin temperature elevation in soft-tissue tumors and identify factors related to skin temperature elevation. Patients and methods This study comprised 118 patients at our hospital with soft-tissue tumors, excluding lipomatous tumors, whose pathological diagnosis was surgically confirmed between February 2017 and March 2021. Sixty-one and 57 patients had been diagnosed with benign lesions and malignant tumors, respectively (men, 64; women, 54; median age, 61 [range, 20–92] years). The relationship between skin temperature, monitored using a thermography camera, and the presence of soft-tissue malignancy was investigated. We reviewed clinical data to identify factors related to elevated skin temperature. Results Temperature differences ≥ 0.2 °C compared to the unaffected side were significantly associated with the presence of malignant tumors ( p < 0.001). Logistic regression analysis indicated that intertumoral blood supply was associated with elevated skin temperature (OR 3.22, 95% CI 2.03–5.13; p < 0.001). Conclusions Elevated skin temperature, influenced by intertumoral blood supply, may be an important adjunct to physical findings when diagnosing malignant soft-tissue tumors. Clinical relevance Intertumoral blood supply influenced elevated skin temperature in malignant soft-tissue tumors. A skin temperature difference ≥ 0.2 °C compared to the unaffected side can help differentiate between benign and malignant tumors. Skin temperature differences may help in diagnosing malignant soft-tissue tumors.

Soft tissue sarcomas with intra-tumour haematoma presented with locally aggressive and highly metastatic behavior, consistent with high-grade tumours.