A rare case of intra-articular synovial sarcoma of the hip joint: a case report with intra-articular findings via hip arthroscopy.

Although synovial sarcoma is a relatively common soft tissue sarcoma, primary intra-articular cases are extremely rare. Herein, we report a case of primary intra-articular synovial sarcoma arising from the hip joint, that was initially treated with hip arthroscopy. A 42-year-old male presented with a history of pain in the left hip for 7 years. Radiography and magnetic resonance imaging revealed the primary intra-articular lesion and simple excision with an arthroscopy was performed. Histological findings revealed spindle cell proliferation with abundant psammoma bodies. SS18 gene rearrangement was confirmed by fluorescence in situ hybridization, and the tumor was diagnosed as synovial sarcoma. Adjuvant chemotherapy and radiotherapy were performed. Local control without metastasis was achieved 6 months after excision. This is the first case of intra-articular synovial sarcoma of the hip joint excised via hip arthroscopy. When an intra-articular lesion is identified, malignancies such as synovial sarcoma should be included in the differential diagnosis.

Effect of Tranilast on the Frequency of Invasive Treatment for Extra-Abdominal Desmoid Fibromatosis.

BACKGROUND: Active surveillance (AS) has been suggested for managing extra-abdominal desmoid fibromatosis (EADF), but a substantial percentage of such patients transitioned to invasive secondary treatments. The anti-keloid medication tranilast is frequently used in Japan but its effectiveness for EADF is not well understood. METHODS: We retrospectively analyzed the medical records of EADF patients treated with tranilast between January 2009 and March 2021. EADF has been reported to shrink spontaneously, so the effects of all drugs must be compared with AS. To assess the effect of tranilast, we compared the clinical courses of patients receiving tranilast with those managed by AS (as identified in a systematic review). A systematic review of AS outcomes was conducted on July 22, 2021, in accordance with PRISMA guidelines. The primary endpoint was rate of conversion to secondary treatment. Secondary endpoints were progression-free survival, objective response rate (ORR), disease control rate (DCR), and adverse events. The rates of conversion to secondary treatment, ORRs, and DCRs were compared between the two groups by using the Fisher exact test. RESULTS: Eighteen patients who received tranilast as initial treatment for EADF were included. Two patients (11.1%) underwent surgical resection for treatment of tumor growth and persistent pain. The rate of conversion to secondary treatment was significantly lower for tranilast than for a pure AS approach (40.1%; p = 0.01). ORR and DCR did not differ between groups. CONCLUSIONS: Tranilast was better than AS for initial management of EADF.

Prevalence and risk factors of preoperative venous thromboembolism in patients with malignant musculoskeletal tumors: an analysis based on D-dimer screening and imaging.

BACKGROUND: Venous thromboembolism (VTE) is a major complication in patients with malignant tumors and orthopedic disorders. Although it is known that patients undergoing surgery for malignant musculoskeletal tumor are at an increased risk of thromboembolic events, only few studies have investigated this risk in detail. Therefore, the aim of this study was to determine the prevalence and risk factors for preoperative VTE in malignant musculoskeletal tumors patients. METHODS: We retrospectively reviewed the medical records of 270 patients who underwent surgical procedures, including biopsy for malignant musculoskeletal tumor, have undergone measurements of preoperative D-dimer levels, and were subsequently screened for VTE by lower extremity venous ultrasonography and/or contrast-enhanced computed tomography scans. Statistical analyses were performed to examine the prevalence and risk factors for VTE. Receiver operating characteristic (ROC) analysis was performed to verify the D-dimer cutoff value for the diagnosis of VTE. RESULTS: Overall, 199 patients (103 with primary soft tissue sarcomas, 38 with primary bone sarcomas, 46 with metastatic tumors, and 12 with hematologic malignancies) were included. D-dimer levels were high in 79 patients; VTE was detected in 19 patients (9.5%). Multivariate analysis indicated that age ≥ 60 years (P = 0.021) and tumor location in the lower limbs (P = 0.048) were independent risk factors for VTE. ROC analysis showed that the D-dimer cutoff value for the diagnosis of VTE was 1.53 µg/mL; the sensitivity and specificity were 89.5% and 79.4%, respectively. CONCLUSIONS: Our study indicated that age and tumor location in the lower limbs were independent risk factors for preoperative VTE in malignant musculoskeletal tumors patients. D-dimer levels were not associated with VTE in the multivariate analysis, likely because they are affected by a wide variety of conditions, such as malignancy and aging. D-dimer is useful for exclusion diagnosis because of its high sensitivity, but patients with high age and tumor location in the lower limbs are a high-risk group and should be considered for imaging evaluation such as ultrasonography regardless of D-dimer levels. TRIAL REGISTRATION: Our study was approved by the institutional review board. The registration number is B200600056 . The registration date was July 13, 2020.

Clinical and pathological analysis of giant cell tumor of bone with denosumab treatment and local recurrence.

BACKGROUND: Giant cell tumor of bone (GCTB) is a primary bone tumor which comprises giant cells and two types of stromal cells. Recent studies have suggested therapeutic risks of denosumab. No previous studies have reported changes in serum TRACP-5b and SUVmax of 18F-FDG-PET/CT in recurred GCTB after denosumab treatment. Therefore, we assessed the relationship between clinical and pathological features of GCTB which recurred after denosumab treatment. METHODS: We retrospectively reviewed the medical records of 26 patients with GCTB who underwent curettage between 2010 and 2018. Fourteen patients treated with denosumab were defined as the denosumab group. We evaluated TRACP-5b and SUVmax values in the denosumab group. H&E staining and immunohistochemistry for H3.3 G34W were performed for pathological assessment. Twelve patients treated without denosumab were defined as the non-denosumab group and compared with denosumab group. RESULTS: The local recurrence rate in the denosumab group was 57.4%. The mean TRACP-5b and SUVmax values were significantly decreased after denosumab therapy (P < 0.001, 1077 ± 161 to 74 ± 9 mU/dL and 8.88 ± 0.40 to 3.79 ± 0.56, respectively). Both parameters significantly increased with local recurrence. H&E staining after denosumab treatment revealed the disappearance of giant cells and histological changes in stromal cells. Specimens of local recurrence subjected to H&E staining and immunohistochemistry for H3.3 G34W demonstrated almost identical features to those in the first biopsy. CONCLUSION: Although denosumab can prevent GCTB from osteolysis, local recurrence cannot be reduced by denosumab treatment. The clinical and pathological results were almost the same as those before denosumab treatment, suggesting that the changes of GCTB by denosumab are reversible.

Characteristics of Patients with Giant Cell Tumor of Bone and High Serum Tartrate-Resistant Acid Phosphatase 5b Levels: Comparison of Tumor Volume and Clinical Factors.

BACKGROUND: Serum tartrate-resistant acid phosphatase 5b is well known to be increased in giant cell tumors of bone. However, there are only a few studies that analyzed the association with tartrate-resistant acid phosphatase 5b expression in those patients. Therefore, we analyzed the characteristics of patients with giant cell tumors of bone and high tartrate-resistant acid phosphatase 5b expression. METHODS: This retrospective study included 26 patients with giant cell tumors of bone. The correlation between tartrate-resistant acid phosphatase 5b before initial treatment and tumor volume was evaluated. Patients were divided into two groups according to tartrate-resistant acid phosphatase 5b level. Statistical analysis was performed between the two groups. RESULTS: Tartrate-resistant acid phosphatase 5b was elevated in 17/26 patients, and the mean value was 852 mU/dL. There was no correlation with tumor volume (r = 0.034, P = 0.86). The mean age of 34.5 years in the HT group was significantly younger than the mean age of 47.4 years in the LT group (P = 0.040). Pathologically, 19/26 cases showed at least one focal area with features of typical giant cell tumor of bone. Although 11/18 patients in the LT group exhibited relatively noticeable secondary changes, all patients in the HT group exhibited typical features (P = 0.0074). CONCLUSIONS: Tartrate-resistant acid phosphatase 5b levels were not elevated in some giant cell tumors of bone. This study suggested that tartrate-resistant acid phosphatase 5b may be elevated in younger patients and in cases with fewer pathological secondary changes, regardless of tumor volume.

A rare case of osteoblastoma in the femoral head combined with cam-type femoroacetabular impingement: A case report.

Osteoblastoma is a relatively rare benign bone-forming tumor accounting for less than 1% of all bone tumors. This report describes a patient with an osteoblastoma in the femoral head complicated by coexistence of femoroacetabular impingement. A 25-year-old male rugby football player complained of severe right hip pain after an injury during rugby practice. The pain became progressively worse despite resting from sports activity and rehabilitation for 4 months. The image inspection revealed bone tumor complicated by cam-type femoroacetabular impingement and a labral injury. Hip arthroscopic surgery was planned using a navigation system and a three-dimensional model for both complete debridement and cam resection. The tumor was resected by open surgery using a posterior approach. The bone tumor was diagnosed histopathologically as an osteoblastoma. The patient's symptoms improved markedly after surgery, with no evidence of local tumor recurrence or hip arthritis 1 year later.

G-CSF Production by Undifferentiated Pleomorphic Sarcoma with Leukemoid Reaction Occurred in the Lower Leg: A Case Report.

CASE: A 46-year-old woman presented with a mass in the lower leg and severe leukocytosis. Diffuse uptake in the bones was detected with F-fluorodeoxyglucose positron emission tomography with computed tomography (F-FDG PET/CT) imaging. The serum granulocyte-colony stimulating factor (G-CSF) was elevated, and immunostaining for G-CSF was positive. When diagnosed as G-CSF-producing undifferentiated pleomorphic sarcoma (UPS), a wide resection was performed. The leukocytosis and serum G-CSF were remarkably improved after tumor resection. No local recurrence or metastasis was detected. CONCLUSION: We report the first case of inflammatory UPS in the extremity which demonstrated the neoplastic production of G-CSF. In our case, F-FDG PET/CT, the serum G-CSF, and immunostaining for G-CSF were useful for diagnosis.