Calcific myonecrosis mimicking soft tissue sarcoma: A case report

Calcific myonecrosis is a rare soft tissue condition. The first case was reported in 1960, however, the precise pathophysiology of calcific myonecrosis remains unclear. The disease was thought to arise from compartment syndrome within a confined space resulting in necrosis and fibrosis, subsequent repeated intralesional hemorrhage, mass enlargement and calcification. Several previous reports have described calcific myonecrosis, which include the formation of calcific myonecrosis after a prolonged period of post trauma. Notably, calcific myonecrosis has typically been described in the lower legs and characteristic imaging findings have been indicated. Furthermore, surgical intervention carries a high risk of complications. In the present case report 2 cases of calcific myonecrosis that occurred after a prolonged period of time following a traumatic event that impacted the lower leg were reported. CT images revealed disruption of calcified fascia and disease expansion into the outside of the fascia. Previous reports have implied that there is late focal enlargement of calcific myonecrosis following earlier enlargement, which may be caused by herniation through muscle fascia. However, no previous publications have focused on images for evidence of late local enlargement. To the best of our knowledge, this is the first report focusing on fascial herniation of calcific myonecrosis using images. Analysis of this feature using images may aid clinicians to differentiate calcific myonecrosis from malignancies.

Atypical femoral fracture associated with bone-modifying agent for bone metastasis of breast cancer: A report of two cases

Atypical femoral fractures (AFFs) are recently observed as a complication of long-term bone-modifying agent (BMA; bisphosphonate or denosumab) therapy for bone metastases. We describe the cases of two women diagnosed with breast cancer who developed incomplete AFF associated with BMAs prescribed for bone metastases. Radiographs of their femurs revealed thickening of the lateral subtrochanteric cortex, and tomosynthesis revealed a visible fracture line in the thickened cortex. They were initially treated with conservative management; however, the incomplete fracture resulted in a complete fracture. These cases highlight two major implications. First, symptomatic incomplete AFF associated with BMAs prescribed for bone metastases should be treated with surgical prophylaxis, given the fact that fracture healing is expected to require a longer duration and an incomplete fracture might potentially progress to a complete fracture during long-term conservative management. Second, tomosynthesis is useful in identifying radiolucent fracture lines that are reliable predictors of fracture propagation.

Trabectedin is a promising antitumor agent potentially inducing melanocytic differentiation for clear cell sarcoma

Clear cell sarcoma is an aggressive soft tissue sarcoma and highly resistant to conventional chemotherapy and radiation therapy. This devastating disease is defined by EWSR1-ATF1 fusion gene resulting from chromosomal translocation t(12;22)(q13;q12) and characterized by melanocytic differentiation. A marine-derived antineoplastic agent, trabectedin, inhibits the growth of myxoid liposarcoma and Ewing sarcoma by causing adipogenic differentiation and neural differentiation, respectively. In this study, we examined the antitumor effects and mechanism of action of trabectedin on human clear cell sarcoma cell lines. We showed that trabectedin decreased the cell proliferation of five clear cell sarcoma cell lines in a dose-dependent manner in vitro and reduced tumor growth of two mouse xenograft models. Flow cytometry and immunoblot analyses in vitro and immunohistochemical analysis in vivo revealed that trabectedin-induced G2/M cell cycle arrest and apoptosis. Furthermore, trabectedin increased the expression of melanocytic differentiation markers along with downregulation of ERK activity in vitro and the rate of melanin-positive cells in vivo. These results suggest that trabectedin has potent antitumor activity against clear cell sarcoma cells by inducing cell cycle arrest, apoptosis, and, in part, by promoting melanocytic differentiation through inactivation of ERK signaling. Our present study indicates that trabectedin is a promising differentiation-inducing agent for clear cell sarcoma.

Therapeutic potential of TAS-115 via c-MET and PDGFRα signal inhibition for synovial sarcoma

Background

The prognosis of synovial sarcoma (SS), an aggressive soft tissue sarcoma, remains poor. We previously reported that c-MET or platelet-derived growth factor receptor α (PDGFRα) signalling pathway is related to SS progression based upon the findings of phospho-receptor tyrosine kinase (RTK) arrays. TAS-115 is a novel c-MET/ vascular endothelial growth factor receptor-targeting tyrosine kinase inhibitor that has been shown to inhibit multiple RTKs. Here we aimed to investigate the therapeutic potential of TAS-115 against SS.

Methods

We first evaluated which signalling pathway was relevant to the viability of three human SS cell lines: Yamato-SS, SYO-1 and HS-SY-II. Next, we assessed the anticancer activity and mechanism of action of TAS-115 in these SS cell lines. Finally, we compared the ability of TAS-115 to inhibit c-MET and PDGFRα phosphorylation with that of pazopanib.

Results

We classified the SS cell lines as c-MET-dependent or PDGFRα-dependent based upon the differences in the signalling pathway relevant for growth and/or survival. We also found that c-MET and PDGFRα were the primary activators of both phosphatidylinositol 3-kinase/AKT and mitogen-activated protein kinase pathways in c-MET-dependent and PDGFRα-dependent SS cells, respectively. TAS-115 treatment blocked the phosphorylation of PDGFRα as well as that of c-MET and their downstream effectors, leading to marked growth inhibition in both types of SS cell lines in in vitro and in vivo studies. Furthermore, PDGFRα phosphorylation, on at least four representative autophosphorylation sites, was impeded by TAS-115 equivalently to pazopanib.

Conclusions

These experimental results have demonstrated the significance of c-MET and PDGFRα signalling for growth and/or survival of SS tumours. TAS-115 monotherapy may benefit SS patients whose tumours are dependent upon either c-MET or PDGFRα signalling by functioning as a multiple tyrosine kinase inhibitor to suppress c-MET as well as PDGFRα pathways.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3324-3) contains supplementary material, which is available to authorized users.

Functional and therapeutic relevance of hepatocyte growth factor/c-MET signaling in synovial sarcoma

Synovial sarcoma (SS) is an aggressive soft tissue sarcoma with a poor prognosis and, thus, novel therapeutic strategies for SS are urgently required. In the present study, we investigated the functional and therapeutic relevance of hepatocyte growth factor (HGF)/c‐MET signaling in SS. Both HGF and c‐MET were highly expressed in Yamato‐SS cells, resulting in activation of c‐MET and its downstream AKT and extracellular signal‐regulated kinase signaling pathways, whereas c‐MET was expressed but not activated in SYO‐1 or HS‐SY‐II cells. c‐MET‐activated Yamato‐SS cells showed higher anchorage‐independent growth ability and less sensitivity to chemotherapeutic agents than did c‐MET‐inactivated SYO‐1 or HS‐SY‐II cells. INC280, a selective c‐MET inhibitor, inhibited growth of Yamato‐SS cells both in vitro and in vivo but not that of SYO‐1 or HS‐SY‐II cells. INC280 induced cell cycle arrest and apoptosis, and blocked phosphorylation of c‐MET and its downstream effectors in Yamato‐SS cells. Co‐expression of HGF and c‐MET in SS clinical samples correlated with a poor prognosis in patients with SS. Taken together, activation of HGF/c‐MET signaling in an autocrine fashion leads to an aggressive phenotype in SS and targeting of this signaling exerts superior antitumor effects on c‐MET‐activated SS. HGF/c‐MET expression status is a potential biomarker for identification of SS patients with a worse prognosis who can benefit from c‐MET inhibitors.

A case report of pancreatic metastasis from synovial sarcoma successfully treated by metastasectomy with adjuvant chemotherapy

INTRODUCTION

Synovial sarcoma is a malignant soft tissue sarcoma which arises near joints. The most frequent metastasis sites of synovial sarcoma are the lungs, lymph nodes, and bone. Pancreatic metastasis is quite rare; only 3 cases have been reported worldwide to date. We herein present the 4th case of pancreatic metastasis from synovial sarcoma.

METHODS AND RESULTS

A 32-year-old man underwent extended excision of synovial sarcoma in the left pelvis and femur in 2009. In 2013, follow-up contrast-enhanced computed tomography revealed a 35-mm heterogeneously enhanced mass in the pancreas body. Endoscopic ultrasound-guided fine needle aspiration of the mass revealed a diffuse proliferation of atypical spindle cells in a fascicular arrangement. Because the histology was quite similar to the resected specimen of synovial sarcoma in 2009, the mass was suspected to be a metastasis from synovial sarcoma. Laparoscopic distal pancreatectomy with adjuvant adriamycin/ifosfamide chemotherapy was subsequently performed. Synovial sarcoma-specific SS18-SSX1 (synovial sarcoma translocation, chromosome 18-synovial sarcoma X1) or SS18-SSX2 chimera mRNA was detected in the resected specimen, confirming the diagnosis of metastasis from synovial sarcoma. The patient did well for 30 months without recurrence.

CONCLUSION

This case suggests that pancreatic metastasis from synovial sarcoma can be successfully treated by metastasectomy with adjuvant chemotherapy.

Radiofrequency ablation of osteoid osteoma using a three-dimensional navigation system

OBJECTIVE

This study aimed to report the clinical outcomes for patients with osteoid osteoma (OO) treated by radiofrequency ablation (RFA) using a three-dimensional (3D) navigation system.

METHODS

We performed RFA using a 3D navigation system on 32 patients with clinically and radiologically diagnosed OO. This study included 25 males and 7 females with a median age of 20 years (range, 10-39 years). The median duration of follow-up was 18 months (range, 1-65 months). We investigated technical specifications, tumor localization, technical success, clinical success, biopsy success, complications, incomplete treatment, and recurrences.

RESULTS

Eighteen tumors were located in the femur, seven in the tibia, two in the humerus, and one each in the fibula, scapula, patella, lumbar vertebra, and acetabula. All procedures were technically successful, and pain relief was achieved in all patients. However, local recurrence developed in one patient, needing additional RFA. The clinical success rate was 96.8%. Biopsy showed OO in 12 patients (37%). Complications occurred in three patients (9%), two cases of fractures and one of osteomyelitis.

CONCLUSIONS

A 3D navigation provides real-time imaging and enables us to set the RFA needle in the correct position, particularly in case of OO-aroused complex anatomical structures. Our initial results indicated that radiofrequency ablation using a 3D navigation system is feasible and safe for patients with OO.

Treatment outcomes of Japanese patients with Ewing sarcoma: differences between skeletal and extraskeletal Ewing sarcoma

OBJECTIVE

The incidence of Ewing sarcoma is lower in non-Caucasian populations, compared with Caucasian populations, for unknown reasons. Most studies from western countries have reported improvement in outcomes following multi-agent chemotherapy, with no difference in outcome between skeletal and extraskeletal Ewing sarcoma. However, there are few studies of Ewing sarcoma in non-Caucasian populations, with especially few comparing outcomes between skeletal and extraskeletal Ewing sarcoma. Thus, the purpose of this study is to determine whether the outcomes and prognostic factors of Ewing sarcoma in the Japanese population are similar to those in Caucasian populations and to determine whether skeletal and extraskeletal Ewing sarcoma have similar outcomes in Japanese patients.

METHODS

We retrospectively evaluated the outcomes of 74 Japanese patients with Ewing sarcoma treated between 1981 and 2011 from the Osaka University Orthopaedic Oncology Group.

RESULTS

Extraskeletal Ewing sarcoma, tumors in the extremities, localized disease at presentation and diagnosis after 2000 were significantly associated with a favorable outcome. Among patients with localized disease at presentation, a significantly better outcome was observed for those with extraskeletal Ewing sarcoma, those who underwent a VDC/IE based or VAIA chemotherapy protocol, and those who were diagnosed after 2000. In the multivariable analyses, extraskeletal Ewing sarcoma was an independent predictor of increased overall survival among all patients and the subset of patients with localized disease.

CONCLUSIONS

The outcome of patients with Ewing sarcoma in Japan has improved in the last decade. The outcomes and prognostic factors are similar for Japanese and Caucasian patients, though in this series of Japanese patients, a better prognosis was observed for patients with extraskeletal rather than skeletal Ewing sarcoma.

Trabectedin is a promising antitumour agent for synovial sarcoma

Synovial sarcoma (SS) is an aggressive soft tissue tumour with poor prognosis. Using five human SS cell lines, we examined the cytotoxic effects of trabectedin (ET-743; Yondelis(®)), a novel marine natural product, which was approved in Europe for the treatment of soft tissue sarcomas (STS). The significant growth inhibitory effects were observed in all SS cell lines below nanomolar concentration of trabectedin. Furthermore, trabectedin significantly suppressed the tumour growth in xenograft models. Flow cytometer analysis in vitro and immunohistochemical analysis in vivo revealed its effect of cell cycle inhibition and apoptosis induction. We also examined the expression of ERCC1, 5 and BRCA1 in SS cell lines and clinical samples, and majority of them showed highly trabectedin-sensitive pattern as previously reported in other cancers. Our preclinical data indicated that trabectedin could be a promising therapeutic option for patients with SS.

Comparison of clinical and functional outcome between surgical treatment and carbon ion radiotherapy for pelvic chondrosarcoma

BACKGROUND

As there are no reports of studies in patients with pelvic chondrosarcoma treated with carbon ion radiotherapy (CIRT), the aim of this study was to evaluate the applicability of CIRT for patients with chondrosarcoma of the pelvis.

METHODS

The medical records of 31 patients with chondrosarcoma of the pelvis treated either by surgical resection or by CIRT between 1983 and 2014 were reviewed. There were 22 males and 9 females with a median age of 43 years (range 16-77 years). The median duration of follow-up was 66 months (range 5-289 months). Twenty-four patients underwent surgery, and 7 patients received CIRT (70.4 GyE in 16 fractions over 4 weeks).

RESULTS

The overall local recurrence rate was 32 %, and the estimated overall 5- and 10-year survival rates were 72 and 57 %, respectively. The mean Musculoskeletal Tumor Society functional score was 59 %. The treatment procedures (surgery or CIRT) did not affect overall survival (P = 0.347). However, the patients who underwent surgery had impaired function compared with those who received CIRT (P = 0.03).

CONCLUSION

Although more patients need to be monitored to assess the clinical and functional outcomes of CIRT for patients with chondrosarcoma of the pelvis, this treatment might offer an acceptable alternative.

A giant periosteal chondroma of the distal femur successfully reconstructed with synthetic bone grafts and a bioresorbable plate: a case report

Periosteal chondromas are rare benign cartilaginous tumors that arise adjacent to the cortex beneath the periosteum. These lesions are usually slow-growing and rarely exceed 3 cm in the greatest dimension. Here, we describe a 17-year-old boy who had a giant periosteal chondroma of the right distal femur, which was treated with intralesional resection and intensive curettage. In addition, we report a novel application of a bioresorbable plate in the management of the large bone defect after resection of a benign bone tumor.

Combined targeting of mTOR and c-MET signaling pathways for effective management of epithelioid sarcoma

Background

Epithelioid sarcoma (EpS) is a high-grade malignant soft-tissue sarcoma characterized by local recurrences and distant metastases. Effective treatments for EpS have not been established and thus novel therapeutic approaches against EpS are urgently required. mTOR inhibitors exert antitumor effects on several malignancies but AKT reactivation by mTOR inhibition attenuates the antitumor effects of mTOR inhibitors. This reactivation is receptor tyrosine kinase (RTK)-dependent due to a release of negative feedback inhibition. We found that c-MET was the most highly activated RTK in two human EpS cell lines, Asra-EPS and VAESBJ. Here we investigated the functional and therapeutic relevance of mTOR and/or c-MET signaling pathways in EpS both in vitro and in vivo.

Methods

We first examined the effects of an mTOR inhibitor, RAD001 (everolimus), on cell proliferation, cell cycle, AKT/mTOR signaling, and xenograft tumor growth in EpS cell lines. Next, we determined whether RAD001-induced AKT reactivation was blocked by silencing of c-MET or treatment with a selective c-MET inhibitor, INC280. Finally, we evaluated the antitumor effects of RAD001 combined with INC280 on EpS cell lines compared with either single agent or control in vitro and in vivo.

Results

Constitutive AKT phosphorylation was observed in Asra-EPS and VAESBJ cells. RAD001 suppressed EpS cell growth by inducing cell cycle arrest but enhanced AKT phosphorylation, which resulted in intrinsic resistance to mTOR inhibitors. In both EpS cell lines, RAD001-induced AKT phosphorylation was dependent on c-MET signaling. INC280 inhibited phosphorylation of c-MET and its downstream molecules, and decreased RAD001-induced phosphorylation of both AKT and ERK in EpS. Compared with a single agent or control, the combination of RAD001 and INC280 exerted superior antitumor effects on the growth of EpS cell lines in vitro and in vivo.

Conclusions

Targeting of mTOR and c-MET signaling pathways significantly abrogates the growth of EpS in preclinical models and may be a promising therapeutic approach for patients with EpS.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-185) contains supplementary material, which is available to authorized users.

Establishment of a novel clear cell sarcoma cell line (Hewga-CCS), and investigation of the antitumor effects of pazopanib on Hewga-CCS

Background

Clear cell sarcoma (CCS) is a therapeutically unresolved, aggressive, soft tissue sarcoma (STS) that predominantly affects young adults. This sarcoma is defined by t(12;22)(q13;q12) translocation, which leads to the fusion of Ewing sarcoma gene (EWS) to activating transcription factor 1 (ATF1) gene, producing a chimeric EWS-ATF1 fusion gene. We established a novel CCS cell line called Hewga-CCS and developed an orthotopic tumor xenograft model to enable comprehensive bench-side investigation for intensive basic and preclinical research in CCS with a paucity of experimental cell lines.

Methods

Hewga-CCS was derived from skin metastatic lesions of a CCS developed in a 34-year-old female. The karyotype and chimeric transcript were analyzed. Xenografts were established and characterized by morphology and immunohistochemical reactivity. Subsequently, the antitumor effects of pazopanib, a recently approved, novel, multitargeted, tyrosine kinase inhibitor (TKI) used for the treatment of advanced soft tissue sarcoma, on Hewga-CCS were assessed in vitro and in vivo.

Results

Hewga-CCS harbored the type 2 EWS-ATF1 transcript. Xenografts morphologically mimicked the primary tumor and expressed S-100 protein and antigens associated with melanin synthesis (Melan-A, HMB45). Pazopanib suppressed the growth of Hewga-CCS both in vivo and in vitro. A phospho-receptor tyrosine kinase array revealed phosphorylation of c-MET, but not of VEGFR, in Hewga-CCS. Subsequent experiments showed that pazopanib exerted antitumor effects through the inhibition of HGF/c-MET signaling.

Conclusions

CCS is a rare, devastating disease, and our established CCS cell line and xenograft model may be a useful tool for further in-depth investigation and understanding of the drug-sensitivity mechanism.