Extraskeletal osteosarcoma has a favourable prognosis when treated like conventional osteosarcoma

The resection of extraosseous osteosarcoma was accompanied by the occurrence of pulmonary metastasis and distal metastasis at the primary site: a case report

Background

Extraskeletal osteosarcoma (ESOS) is a rare and aggressive malignancy, comprising approximately 1% of all soft tissue sarcomas and 4.3% of all osteosarcomas. It predominantly affects individuals between the ages of 48 and 60, with a slightly higher incidence observed in males compared to females. The clinical diagnosis of ESOS poses a significant challenge due to its atypical presentation and overlap with other soft tissue neoplasms. Despite advances in diagnostic imaging and histopathological techniques, there is currently no consensus on the optimal treatment strategy.

Case presentation

We report a case of a 64-year-old Chinese woman with ESOS of the left knee for 7 years, who experienced multiple recurrences after surgical resection, accompanied by systemic multiple soft tissue metastases and lung metastases. Initially, the patient found a painless mass in the left knee, which was diagnosed as a benign soft tissue mass at a local hospital and surgically removed. However, two years after the surgery, a mass recurred around the left knee and was larger than before, prompting the patient to seek treatment at our department. The patient underwent standard surgical treatment in our department, and postoperative histopathology, genetic testing, and immunohistochemical examination all confirmed the diagnosis of ESOS. Over the course of 5 years, the patient experienced multiple recurrences, and we attempted surgical treatment combined with chemotherapy and targeted therapy. Ultimately, due to multiple tumor ruptures in the left lower limb, severe pain, and sleep disorders, the patient decided to undergo left hip disarticulation surgery.

Conclusion

The diagnosis and treatment of ESOS are challenging and require multimodal examination, including histological and immunohistochemical analysis. ESOS is rare, especially when it metastasizes to the distal soft tissues of the primary lesion site, which may portend a poorer clinical outcome compared to pure pulmonary metastasis. Despite current therapeutic interventions, this case still emphasizes its aggressiveness and poor prognosis.

Primary extraskeletal osteosarcoma of rectal mesentery: a rare case and literature review

BACKGROUND

Extraskeletal osteosarcoma (ESOS) is a rare kind of sarcoma with a low preoperative diagnosis and a poor prognosis. ESOS arising from abdominal mesentery is extremely rare. Increasing diagnostic methods and standardizing treatment protocols are crucial issues of ESOS.

CASE PRESENTATION

We report the case of a 52-year-old female ESOS patient. She had a history of ovarian carcinoma (stage IIIC) surgery two years before, with five cycles of chemotherapy. A mass was found during postoperative examinations. A R0 surgical resection was performed. Post-operational pathological report plus intra-surgery findings supported a diagnosis of ESOS. She is still alive 10 months post-operationally, with routine blood and radiographical examinations.

CONCLUSION

Enhancing awareness of this extremely rare disease together with advancements in diagnostic methods will hopefully enable earlier recognition and initiation of treatment. Protocols for standardizing treatments require a larger multi-center collaboration and more data analysis.

An analysis of extraskeletal osteosarcoma based on the literature

Extraskeletal osteosarcoma (ESOS) is a very rare malignant tumor. This study aimed to provide more evidence about the natural history and clinical features of ESOS, and clarify the impact of chemotherapy (CT) and radiotherapy (RT) on patient survival and postoperative recurrence for the sake of gaining a better understanding about the disease. Patient/tumor characteristics, recurrence, treatment, and follow-up durations were collected by searching studies in PubMed, Web of Science, Ovid, Elsevier, SpringerLink, Chinese National Knowledge Infrastructure (CNKI), and WAN FANG Data before June 30, 2023. Data were analyzed by SPSS-26. Altogether 1287 patients diagnosed with ESOS were retrieved from the literature. Of them, follow-up data were available in 981 patients, in whom 78 patients (7.6%) had metastases and 730 patients (74.5%) had localized disease at the time of diagnosis. Of the 730 patients with localized disease, 682 (93.4%) received surgical resection. The 5-year OS in all 981 patients, 78 metastatic patients, and 682 patients with localized disease was 33.40%, 4.9% and 41.1%, respectively. Of the 682 surgical patients, 367 patients underwent surgical resection alone, 170 received surgical resection + CT, 82 patients received surgical resection + RT, and 58 patients received both adjuvants. In addition, 348 (51%) of the 682 patients developed recurrence, including local recurrence (n = 102), metastasis (n = 130), and both (n = 116). Univariate analysis of 5-year PFS and 5-year OS showed that age, tumor size, CT, metastasis, and local recurrence were significant prognostic factors in the 682 patients with localized disease. There was no significant difference in 5-year OS between osteosarcoma-type and soft tissue-type regimens (P = 0.273). Multivariate analysis of 431 patients showed that postoperative recurrence and metastasis were significant prognostic factors for survival, and CT was not a significant prognostic factor, though CT decreased the incidence of local recurrence in ≤ 45-year age group (P = 0.047). RT reduced the incidence of local recurrence in patients ≤ 45years (P = 0.035) and patients with tumors > 5 cm (P = 0.044). So, we recommend that CT should be used for patients aged ≤ 45years, and RT can be used for patients ≤ 45years or those with tumors > 5 cm for the sake of decreasing the incidence of local recurrence, which we believe would indirectly benefit the survival of ESOS patients.

Conoccurence of extraskeletal osteosarcoma and undiagnosed Paget disease in a 49-year-old female

Extraskeletal osteosarcoma (ESOS) represents a rare soft tissue entity, accounting for ⁓1% of all soft tissue malignancies. It is generally considered to have an even worse prognosis than bone osteosarcoma, therefore detailed investigations and proper treatment are required. ESOSs arising in the subcutaneous tissue are even rarer than the ones positioned in deep tissues, and they are considered to have far better outcomes. We present a case of a 49-year-old patient diagnosed with subcutaneous ESOS and Paget disease of the bone, which is not typical for the patient's age, considering that Paget disease of the bone tends to affect a population above 50 years. The coexistence of these two entities in a single patient and all their features make this case unique, and to the best of our knowledge, this is the first case reported.

Recurrent Osteosarcoma Presenting as Hepatic Metastasis: A Case Report

Osteosarcoma is a malignant tumor, derived from primitive bone-forming mesenchymal cells, and its aggressive nature often leads to significant morbidity and mortality, with amputation being routinely performed in localized cases. Post-amputation morbidity has a significant impact on the quality of life of the affected individuals. The tumor frequently metastasizes to the lungs and bones, and widespread disease remains the leading cause of most patient deaths. Other metastatic sites are extremely rare. We report a rare case of a young boy who had developed osteosarcoma and was surgically treated, without any metastatic disease. Two years later, the patient developed an abdominal mass, which was diagnosed as metastatic osteosarcoma to the liver.

Extraskeletal osteosarcoma infiltrating pancreas, spleen, gastric, and left kidney: a case report

BACKGROUND

Extraskeletal osteosarcoma is an extremely rare malignancy that accounts for 1% of soft tissue sarcoma and 4.3% of all osteosarcoma. Extraskeletal osteosarcoma can develop in a patient between the ages of 48 and 60 years. The incidence of extraskeletal osteosarcoma is slightly higher in male patients than in females.

CASE PRESENTATION

A 50-year-old Caucasian male patient presented with a 6-month history of intermittent lower-left back pain that limits his activity. Prior ultrasonography and abdominal computed tomography scan showed a diagnosis of kidney stone and tumor in the lower-left abdomen. The computed tomography urography with contrast revealed a mass suspected as a left retroperitoneal malignant tumor. Hence, the tumor was resected through laparotomy and the patient continued with histopathological and immunohistochemistry examination with the result of extraskeletal osteosarcoma.

CONCLUSION

Extraskeletal osteosarcoma presents diagnostic challenges requiring multimodal examination, including histological and immunohistochemistry analyses. This case underscores the aggressive nature and poor prognosis despite undergoing the current suggested treatment.

Imaging diagnosis and differential diagnosis of extraskeletal osteosarcoma

OBJECTIVE

The aim of this study was to investigate the clinical, imaging and pathological features of extraskeletal osteosarcoma (EOS) and to improve the understanding of this disease and other similar lesions.

METHODS

The data for 11 patients with pathologically confirmed extraosseous osteosarcoma, including tumour site and size and imaging and clinical manifestations, were analysed retrospectively.

RESULTS

Six patients were male (60%), and 5 were female (40%); patient age ranged from 23 to 76 years (average age 47.1 years). Among the 11 patients, 7 had clear calcifications or ossification with different morphologies, and 2 patients showed a massive mature bone tumour. MRI showed a mixed-signal mass with slightly longer T1 and T2 signals in the tumour parenchyma. Enhanced CT and MRI scans showed enhancement in the parenchyma. Ten patients had different degrees of necrosis and cystic degeneration in the mass, 2 of whom were complicated with haemorrhage, and MRI showed "fluid‒fluid level" signs. Of the 11 patients, five patients survived after surgery, and no obvious recurrence or metastasis was found on imaging examination. One patient died of lung metastasis after surgery, and 2 patients with open biopsy died of disease progression. One patient died of respiratory failure 2 months after operation. 2 patients had positive surgical margins, and 1 had lung metastasis 6 months after operation and died 19 months after operation. Another patient had recurrence 2 months after surgery.

CONCLUSION

The diagnosis of EOS requires a combination of clinical, imaging and histological examinations. Cystic degeneration and necrosis; mineralization is common, especially thick and lumpy mineralization. Extended resection is still the first choice for localized lesions. For patients with positive surgical margins or metastases, adjuvant chemoradiotherapy is needed.

Establishment and functional testing of a novel ex vivo extraskeletal osteosarcoma cell model (USZ20-ESOS1)

Extraskeletal osteosarcoma (ESOS) is a rare malignant mesenchymal tumor that originates in the soft tissue. ESOS accounts for less than 1% of all soft tissue sarcomas and exhibits an aggressive behavior with a high propensity for local recurrence and distant metastasis. Despite advances in treatment, the prognosis for ESOS remains poor, with a five-year survival rate of less than 50% and 27% for metastatic patients. Ex vivo models derived from patient samples are critical tools for studying rare diseases with poor prognoses, such as ESOS, and identifying potential new treatment strategies. In this work, we established a novel ESOS ex vivo sarco-sphere model from a metastatic lesion to the dermis for research and functional testing purposes. The ex vivo cell model accurately recapitulated the native tumor, as evidenced by histomorphology and molecular profiles. Through a functional screening approach, we were able to identify novel individual anti-cancer drug sensitivities for different drugs such as romidepsin, miverbresib and to multiple kinase inhibitors. Overall, our new ESOS ex vivo cell model represents a valuable tool for investigating disease mechanisms and answering basic and translational research questions.

Survival Differences of Patients with Resected Extraskeletal Osteosarcoma Receiving Two Different (Neo)Adjuvant Chemotherapy Regimens: A Systematic Review and Meta-analysis

AIMS

Extraskeletal osteosarcoma (ESOS) is a malignant tumour developing in soft tissues, characterised by the production of osteoid or bone matrix by tumour cells. The standard treatment for localised ESOS is wide resection. Radiotherapy and chemotherapy are usually incorporated into the management of patients. Two types of chemotherapy regimen are mostly used: an osteosarcoma-type chemotherapy, based on cisplatin, and a soft-tissue sarcoma (STS)-type chemotherapy, using the combination of doxorubicin and ifosfamide. To investigate the difference in survival between these two chemotherapy regimens, a systematic review of studies reporting the 5-year disease-free survival (DFS) rates among patients with ESOS submitted to surgery and who received (neo)adjuvant chemotherapy with osteosarcoma-type or STS-type chemotherapy was carried out.

MATERIALS AND METHODS

Of the 401 articles identified by systematically searching the PubMed, Embase and Cochrane Central Register of Controlled Trials databases, six retrospective studies were included in the final analysis. In total, 319 patients with localised/resected ESOS were included in the study.

RESULTS

Our meta-analysis showed a benefit in 5-year DFS favouring the use of osteosarcoma-type chemotherapy (relative risk = 1.32, 95% confidence interval 1.03-1.69; P = 0.54); I2 heterogeneity was 0%. The 5-year DFS rate was 56.3% (95% confidence interval 48.3-64.3) with osteosarcoma-type chemotherapy and 45.2% (95% confidence interval 34.5-55.9) with STS-type chemotherapy, with I2 heterogeneity of 27% and 0%, respectively.

CONCLUSIONS

Our analysis suggests that there may be a difference regarding the type of (neo)adjuvant chemotherapy regimen used in the treatment of patients with resected ESOS in favour of osteosarcoma-type chemotherapy. Future studies evaluating the role of this treatment modality in this scenario need to consider the type of chemotherapy regimen when comparing with an arm of surgery with/without radiotherapy alone.

Primary cutaneous extraskeletal osteosarcoma: a series of 16 cases

Extraskeletal osteosarcoma (EOS) is a high grade soft tissue tumour characterised by the production of malignant osteoid, without attachment/involvement of underlying bone/periosteum. Rarely, EOS presents as a cutaneous tumour. The clinical behaviour of primary cutaneous EOS (PC-EOS) remains incompletely characterised. Herein we present the largest case series of PC-EOS reported to date. Sixteen PC-EOS cases from the archives/consultation files were retrieved (male:female 1:1; age 31-96 years, mean age 66 years). The tumours measured 1-10 cm (mean 3.2 cm) and were located on the lower extremity (7), head (6), upper extremity (2), and trunk (1). They consisted of pleomorphic, spindled-to-epithelioid cells, with fascicular, nodular, or sheet-like growth patterns and foci of malignant osteoid. Immunohistochemistry did not reveal specific lines of differentiation, and there was no evidence of other tumour types. A literature review was conducted to identify all well characterised cases of PC-EOS. A combined analysis of present and past cases was performed to determine overall trends in clinical characteristics and outcomes. The mean follow-up period was 23.9 months, during which 67.5% of patients experienced progression-free survival and 18% of patients died of disease. Rates of local recurrence and metastasis were 10% and 25%, respectively, approximately double past estimates. These data suggest that the prognosis of PC-EOS is less favourable than previously thought. The differential diagnosis includes benign entities (e.g., ossifying pyogenic granuloma) and malignant neoplasms with heterologous osteosarcomatous differentiation (e.g., carcinosarcoma, transdifferentiated melanoma). Wide excision remains the standard of care, and the role of chemotherapy and radiation remains inconclusive. Recognition of this rare entity can facilitate prompt diagnosis and appropriate treatment.

Establishment, Maintenance, and Performance of the Cooperative Osteosarcoma Study Group (COSS)

INTRODUCTION

Osteosarcoma treatment has benefitted greatly from collaborative research. This paper describes the history and accomplishments of the Cooperative Osteosarcoma Study Group (COSS), mainly dedicated to clinical questions, as well as remaining challenges.

MATERIALS AND METHODS

Narrative review of over four decades of uninterrupted collaboration within the multi-national German-Austrian-Swiss COSS group.

RESULTS

Since its very first prospective osteosarcoma trial starting in 1977, COSS has continuously been able to provide high-level evidence on various tumor- and treatment-related questions. This includes both the cohort of patients enrolled into prospective trials as well as those patients excluded from them for various reasons, followed in a prospective registry. Well over one hundred disease-related publications attest to the group's impact on the field. Despite these accomplishments, challenging problems remain.

DISCUSSION

Collaborative research within a multi-national study group resulted in better definitions of important aspects of the most common bone tumor, osteosarcoma, and its treatments. Important challenges continue to persist.

The Effect of Adjuvant Chemotherapy on Localized Extraskeletal Osteosarcoma: A Systematic Review

(1) Background: Extraskeletal osteosarcoma (ESOS) is a malignant tumor characterized by the production of bone or bone matrix by tumor cells without any continuity into the skeletal bones. The standard treatment for localized ESOS is wide resection; however, the effect of (neo)adjuvant chemotherapy remains unclear. To investigate the effect of (neo)adjuvant chemotherapy for localized ESOS, we conducted a systematic review of studies comparing the 5-year disease-free survival rate between patients who underwent surgery combined with (neo)adjuvant chemotherapy and those who underwent surgery alone. (2) Methods: Of the 210 studies identified by systematically searching the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases, 12 were included in the final analysis. These 12 articles were not randomized controlled trials, but retrospective studies. In total, 761 patients with localized ESOS were included in this study. (3) Results: The 5-year disease-free survival rate was 47.9% (187 of 390 patients) in the surgery and (neo)adjuvant chemotherapy group and 40.4% (150 of 371 patients) in the surgery alone group. The overall pooled odds ratio was 1.23 (95% confidence interval, 0.69-2.19; p = 0.479) and the heterogeneity I² was 37%. (4) Conclusions: The effect of adjuvant chemotherapy on localized ESOS seems to be limited. Therefore, routine use of adjuvant chemotherapy for localized ESOS should be avoided. However, further randomized controlled trials are required to confirm these results.

Fibro-Osseous Pseudotumor

Fibro-osseous pseudotumor is an extremely rare subcutaneous benign ossifying lesion associated with bone formation that is most commonly seen in the hands, followed by the toes. Because the tumor has a certain degree of invasiveness, it is often mistaken for malignancy, which leads to radical, excessive treatment. Our case involved a 32-year-old man with lesions on the left index finger. We documented the detailed data of diagnosis, treatment, and follow-up. We also conducted a review and summarized the published cases to advance our understanding of the disease, provide more accurate diagnostic criteria, and avoid inappropriate surgical procedures. [Orthopedics. 2021;44(6):e713-e718.].

Primary Osteosarcoma of the Urinary Bladder Metastatic to Lung

Extra-skeletal osteosarcoma (ESOS) is a rare neoplasm that represents less than 2% of all soft tissue sarcomas. Common reported sites of involvement include limbs, retroperitoneum, chest wall and buttocks. ESOS arising primarily in parenchymatous organs are extremely uncommon, with the involvement of the urinary bladder is even rarer. We herein report a case of primary ESOS of the urinary bladder in a 48 year-old male patient.

Post-traumatic myositis ossificans: a benign lesion that simulates malignant bone and soft tissue tumours

Myositis ossificans (MO) is a benign bone formation in an extra-skeletal location. The most common subtype of MO, the post-traumatic, usually develops in young males after a traumatic event or sports injury.MO may simulate malignant bone lesions such as extra-skeletal or surface osteosarcomas, or soft tissue sarcomas such as synovial sarcoma or undifferentiated pleomorphic sarcoma. In the early phase the diagnosis of MO is challenging because imaging and histopathological findings may be non-characteristic.Detailed medical history as well as clinical examination, follow-up imaging studies and histological assessment are crucial for a proper diagnosis. Early and accurate differential diagnosis between MO and malignant soft tissue and bone tumours is important to maximize. Cite this article: EFORT Open Rev 2021;6:572-583. DOI: 10.1302/2058-5241.6.210002.

Unusual Presentation of Widely Metastatic Extraskeletal Osteosarcoma: Case Report

Extraskeletal osteosarcoma is a highly aggressive malignant osteoid forming mesenchymal neoplasm arising from soft tissues which accounts for 1% of all soft tissue sarcomas. We report the case of a 46-year-old female with no significant past medical history presenting to an emergency department with a right lateral thigh mass following minor trauma. She was eventually found to have high grade extraskeletal osteosarcoma with rapid progression of disease resulting in patient demise. Differentiation of these lesions from alternative processes relies on specific imaging and pathologic features. Differential diagnoses include both benign and malignant etiologies such as myositis ossificans, soft tissue hemangiomas, and other malignant soft tissue neoplasms such as epithelial and synovial sarcoma.

Extraskeletal osteosarcomas: current update

Extraskeletal osteosarcoma is a very infrequently diagnosed soft-tissue sarcoma subtype which has identical histological features to bone osteosarcoma. However, its demographics, presentation, radiology and treatment strategy differ from those of osteosarcoma. Its diagnosis can be at times challenging due to radiological and pathological mimics which have more common incidence. A multimodality approach is essential for optimizing the outcomes in extraskeletal osteosarcoma. Although there are certain caveats on inclusion of adjuvant therapies (radiotherapy and chemotherapy), in all cases surgical resection with wide local margins is considered the gold standard for adequate local control. The outcome in advanced disease remains dismal and there is a huge unmet need for prospective studies addressing the optimal treatment strategy. In this article, we review the evidence available for the management of extraskeletal osteosarcoma.

Primary orbital extraskeletal osteosarcoma and review of literature

Background

Extraskeletal osteosarcoma is a malignant tumour composed of an osteoid and/or cartilaginous matrix; it arises in soft tissues without connection to the skeleton, and to our knowledge, this type of tumour is extremely rare.

Case presentation

The present study reports a 57-year-old man with primary orbital extraskeletal osteosarcoma who presented with a history of painful swelling in the left orbit that had occurred for 11 months. Imaging of the orbit showed an atypical, well-defined heterogeneous mass attached to the posterior globe of the left orbit. The patient underwent an anterior orbitotomy and complete excision of the tumour. The mass was originated from neither the globe nor the bony orbital wall but from the soft tissue. Histopathology demonstrated an extraskeletal osteosarcoma. After 13 months of follow-up, there was apparent recurrence of the tumour. The medical history showed no complaints of previous trauma or radiotherapy.

Conclusions

ESOS is a highly malignant tumour. Immunosuppression, trauma and adjuvant radiotherapy are possible predisposing factors in the development of this tumour. Prompt recognition and thorough treatment are essential for preventing orbital lesions and presence of metastasis from other organs.

The Role of Chemotherapy in Extraskeletal Osteosarcoma: A Propensity Score Analysis of the Surveillance Epidemiology and End Results (SEER) Database

BACKGROUND Incidence of extraskeletal osteosarcoma (ESOS) is extremely low and the prognosis remains unclear. We conducted this study to explore prognostic factors and the role of chemotherapy in ESOS. MATERIAL AND METHODS We screened data from the Surveillance Epidemiology and End Results (SEER) database (1975-2016). Three hundred ten patients with ESOS were included and 49.4% (107/310) of them underwent chemotherapy. We performed logistic regression analysis to investigate potential factors determining selection of chemotherapy. An inverse probability of treatment weighting (IPTW) and propensity score matching (PSM)-adjusted Kaplan-Meier curve was created and log-rank test and Cox regression analysis were performed to compare overall survival (OS) and cancer-specific survival (CSS) in patients treated with and without chemotherapy. Subgroup analysis also was conducted based on age, tumor site, stage, size, and surgery. RESULTS Chemotherapy in ESOS was not associated with improved OS in the unmatched cohort (HR, 0.764; 95% CI, 0.555-1.051; p=0.098). The insignificant treatment effect of chemotherapy was also noted in IPTW-adjusted (HR, 0.737; 95% CI, 0.533-1.021; p=0.066) and PSM-adjusted (HR, 0.804; 95% CI, 0.552-1.172; p=0.257) Cox regression analysis. The insignificant treatment effect was consistent across all subgroups and there was no significant heterogeneity of chemotherapy effect (all p for interaction >0.05). CONCLUSIONS The study suggested that chemotherapy has no significant benefit on prognosis of patients with ESOS. These findings should be considered when making treatment decisions about patients with ESOS.

Extraskeletal osteosarcoma misdiagnosed as heterotopic ossification after periprosthetic femoral fracture: A case report

Extraskeletal osteosarcoma is a malignant tumor of soft tissue characterized by osteoid production and has a very low prevalence, comprising approximately 4% of all osteosarcomas and about 1% of all soft tissue sarcomas, and a total of about 350 cases have been reported until now. Heterotopic ossification is a pathological finding of bony tissue in soft tissue regions such as muscle, skin and subcutaneous tissue. We report a case of an 86-year-old woman with a history of total hip arthroplasty (THA), in which open reduction and internal fixation were done for periprosthetic femoral Fracture. The ossified lesion misdiagnosed as heterotopic ossification initially was diagnosed as extraskeletal osteosarcoma at 6 months after the surgery. Both extraskeletal osteosarcoma and heterotopic ossification have no definite symptoms, but show radiopaque shadows on simple radiograph. Therefore, careful attention and thorough evaluation with multiple imaging tests may be necessary for the differential diagnosis of these entities.

Extraskeletal Osteosarcoma: Outcomes and the Role of Chemotherapy

OBJECTIVES

Extraskeletal osteosarcoma (EO) is a malignant neoplasm that produces osteoid, bone, and chondroid material without direct attachment to bone or periosteum. Surgical resection is the mainstay of treatment; the role of chemotherapy is not well defined. Therefore, we evaluated the impact of chemotherapy in the survival of patients with EO.

METHODS

All EO patients seen at Mayo Clinic between 1990 and 2014 were assessed. Forty-three patients were included after all archived pathology slides were reviewed to confirm the diagnosis of EO.

RESULTS

Of 43 patients, 37 patients had localized disease and 6 patients had metastatic disease at diagnosis. Chemotherapy was used in 73% and 75% of patients, respectively. Chemotherapy was predominantly anthracycline based, and included platinum in 22 patients (84%).Median overall survival (OS) and progression-free survival (PFS) were 50 months (95% confidence interval, 25-99), and 21 months (95% confidence interval, 13-not reached), respectively. There was a trend towards longer OS and PFS in patients who received chemotherapy. Those who received platinum-based therapy had remarkably prolonged OS (median, 182 vs. 18 mo; 5-year, 61% vs. 0%; P=0.01) and PFS (median, not reached vs. 10 mo; 5-year, 56% vs. 0%; P=0.005). Baseline characteristics were similar in the platinum and nonplatinum group.In patients who received chemotherapy, relapse/recurrence rate was lower in the platinum-based group (41%) as opposed to the nonplatinum-based group (100%; P=0.02). In the neoadjuvant setting, the overall response rate of platinum-containing regimens was 27%.

CONCLUSIONS

Our results suggest a clinical benefit when platinum-based chemotherapy is incorporated in the management of patients with EO. We plan to validate this further with an expanded multicenter analysis.

Primary extraskeletal osteosarcoma of the mesentery: A case report

•

Extraskeletal osteosarcoma is a rare malignant soft tissue tumor without attachment to the bone.

•

This is the first report of a single incisional laparoscopic resection.

•

Its diagnosis should be taken into consideration also when a soft tissue mass of the mesentery is found.

Introduction

Extraskeletal osteosarcoma is a rare malignant soft tissue tumor without attachment to the bone. To the best of our knowledge, we present here the first report of a primary extraskeletal osteosarcoma of the mesentery in Japan.

Case presentation

A 46-year-old female underwent a health examination, with no complaint. Following an ultrasonography a solid mass was detected in the abdominal cavity. Computed tomography showed a 38 × 25 mm heterogeneously enhancing mass. The latter was characterized by the presence of mottled calcifications and a cystic portion. The tumor was resected with a single incisional laparoscopic curative resection. Histopathological examination revealed the presence of a primary extraskeletal osteosarcoma arising from the mesentery. Postoperative course was uneventful. The patient did not receive chemotherapy during follow-up. She was recurrence free 10 months post-surgery.

Discussion

Patients with extraskeletal osteosarcoma generally have a poor prognosis. A tumor size <5 cm represents an important prognostic factor. Unexpectedly, our case was detected by ultrasonography at an early stage. This is the first report of a single incisional laparoscopic resection.

Conclusion

A primary extraskeletal osteosarcoma of the mesentery is an extremely rare occurrence. Its diagnosis should be taken into consideration also when a soft tissue mass of the mesentery is found.

Ossifying fasciitis at an extraordinary site - a case report and analysis of diagnostic pitfalls

Ossifying fasciitis is a very rare disease of reactive character; however, it can mimic malignant lesions, especially osteosarcoma. We report a case of a 30-year-old woman, who experienced a rapidly growing painful lesion of the left knee joint, preceded by a trauma. The tumor was resected, and the histopathological image suggested a malignant lesion with features of an osteosarcoma. A detailed correlation with a clinicopathological and radiological analysis led to the final diagnosis of ossifying fasciitis at an extraordinary site of patellar retinaculum. Our case shows that the close similarity between ossifying fasciitis and osteosarcoma may be challenging.

Prognostic implication of adjuvant/neoadjuvant chemotherapy consisting of doxorubicin and ifosfamide in patients with extraskeletal osteosarcoma

BACKGROUND

Extraskeletal osteosarcoma (ESOS) is an extremely rare soft tissue sarcoma. Their prognosis remains poor. Our purposes were to identify the effective chemotherapeutic regimen for ESOS.

METHODS

We retrospectively reviewed 16 patients with ESOS treated at the Osaka University Orthopaedic Oncology Group between 1992 and 2012. We extracted the clinical data on patients. Kaplan-Meier method and the log-rank test were used for survival analyses.

RESULTS

Median age of the patients was 61.5 years (range 25-79 years). Wide local excision was performed for 11 patients and 9 patients were treated combined with chemotherapy. The 5-year disease-specific survival (DSS) rate was 53.9%. The 5-year DSS rates for patients treated with adjuvant/neoadjuvant chemotherapy or not were 66.7% or 25%, respectively (p = 0.0215). Furthermore, the 5-year DSS rates for patients treated with adjuvant/neoadjuvant chemotherapy consisting of doxorubicin and ifosfamide and those treated with other regimens were 100% or 40%, respectively (p = 0.0327).

CONCLUSION

The present study demonstrated that adjuvant/neoadjuvant chemotherapy, especially consisting of doxorubicin and ifosfamide, was potentially efficacious for ESOS. Further prospective study using this multimodality treatment approach to patients with ESOS should be strongly warranted.

A rare variant of extraskeletal osteosarcoma presenting as a clinically benign subcutaneous neoplasm

Extraskeletal osteosarcoma (ESOS) is a rare variant of osteosarcoma that arises without attachment to the underlying skeleton. These cancers are typically found embedded in deeper tissues, most commonly the muscle or fascia, and are rarely found within the skin or subcutis. Most tumors are large in size upon initial presentation, and carry a poor prognosis. We discuss the case of a 48-year-old Caucasian woman who presented to a dermatology clinic with an asymptomatic, small, mobile, subcutaneous mass that appeared clinically benign. After elective removal and histopathologic examination, the patient was diagnosed with ESOS. ESOS presenting in this manner is exceedingly rare, and this case highlights the importance of sending all excised specimens, even those with a benign presentation, for pathologic examination.

Outcomes of surgery and/or combination chemotherapy for extraskeletal osteosarcoma: a single-center retrospective study from China

Extraskeletal osteosarcoma (ESOS) is an extremely rare malignancy with poor prognosis, accounting for 2-4% of all osteogenic sarcomas. The purpose of this study was to examine the oncological outcomes of this disease related to surgical treatment and/or combined adjuvant therapies and to analyze the associated prognostic factors in ESOS. From January 1990 to June 2016, 22 patients with primary ESOS were analyzed in this retrospective study. Overall survival (OS) and progression-free survival (PFS) rates were calculated by Kaplan-Meier methods and compared with log-rank test. 22 patients were diagnosed with ESOS, 19 showed localized diseases and 3 presented with metastatic lesions. The median age at diagnosis was 55.5 years. Surgery resection was performed for all patients, 18 of whom received adjuvant chemotherapy. The median follow-up time was 48.5 months. There were 10 cases of recurrence and 9 patients developed new metastases. The 5-year OS rate for all patients was 58%. For localized cohort, the 5-year OS rate was 62%, and the 3-year PFS rate was 31% with a median PFS of 16 months. Univariate analysis of related prognosis factors showed that larger size of tumor (>5.5 cm) and higher histologic grade emerged as significant factors associated with worse OS. The addition of combination chemotherapy has no effect found on OS or PFS in this study. In summary, for patients who presented with ESOS, larger tumor size and higher histologic grade indicate a lower OS rate. The combination chemotherapy does not improve the OS or PFS.

Extraskeletal Osteosarcomas: A Case Made for Combined Modality Local Therapy With Radiation and Surgery

OBJECTIVE

We evaluated our experience treating patients with extraskeletal osteosarcoma (ESOS) using combined modality local therapy, including surgery and radiation therapy (RT), to investigate local control (LC) and other survival endpoints.

METHODS

We reviewed the records of 21 consecutive patients with nonmetastatic, ESOS treated with RT in combination with surgery at our institution from 1984 to 2015. Postoperative RT was used for 10 patients (48%) to a median dose of 60 Gy (range, 60 to 68 Gy). The other 11 patients (52%) received 50 Gy preoperatively. Seven patients (33%) were treated with neoadjuvant or adjuvant chemotherapy. Among the patients who received chemotherapy, all were treated with doxorubicin and ifosfamide for a median of 6 cycles (range, 4 to 6).

RESULTS

Median follow-up time was 120 months (range, 6 to 200 mo). Larger tumor size (>5 cm) was associated with chemotherapy use (P=0.046). The 5-year LC, distant metastatic free survival, and disease-specific survival rates were 93%, 53%, and 62%, respectively. Only 1 patient (5%) had a local recurrence at 22 months. Nine patients (43%) developed distant metastases at a median time of 9 months (range, 1 to 30 mo) without any significant factors for reduced distant metastatic free survival. Following disease relapse, there were 2 patients who were ultimately salvaged, both of whom were treated with chemotherapy and surgery.

CONCLUSIONS

RT in combination with surgery provides favorable LC for patients with ESOS. However, patients have a high rate of distant metastases with limited salvage.

Primary Extraskeletal Osteosarcoma Arising from the Optic Nerve: A Rare Case Report

Orbital location of extraskeletal osteosarcoma is extremely rare with only 4 cases reported so far in the English literature. We present the case of a 32-year-old female who presented with proptosis and complete loss of vision of the left eye. Contrast-enhanced computed tomography scan showed a densely calcified lobulated lesion in the left optic nerve showing strong enhancement. A left fronto-occipito-zygomatic osteotomy was conducted and a greyish brown tumor was identified. Histopathological and immunohistochemical examination of the curetted material revealed it to be extraskeletal osteosarcoma. A left partial maxillectomy with ethmoidectomy and left orbital exenteration was done and the patient was advised chemotherapy with radiotherapy.

Subclassification of pleomorphic sarcomas: How and why should we care?

Pleomorphic sarcomas are a heterogeneous group of mesenchymal neoplasms with widely varied clinical behavior but overlapping histologic appearances. The following guidelines are helpful when approaching the diagnosis of a pleomorphic sarcoma. (1) Be aware of the relative incidence of the various sarcoma types: several pleomorphic sarcomas are relatively common (e.g., dedifferentiated liposarcoma and undifferentiated pleomorphic sarcoma), whereas others are exceptionally rare. (2) Pay attention to anatomic location: some pleomorphic sarcomas have a predilection for somatic soft tissues, especially the thigh (e.g., undifferentiated pleomorphic sarcoma, pleomorphic liposarcoma, pleomorphic rhabdomyosarcoma), whereas other pleomorphic sarcomas most often arise in the retroperitoneum (e.g., dedifferentiated liposarcoma). (3) Carefully sample the resection specimen, paying particular attention to areas with differences in gross appearances (e.g., fleshy, fibrous, mucoid, or gritty). (4) Search for histologic clues (i.e., myxoid stroma, lipoblasts, and osteoid matrix, in order to diagnose myxofibrosarcoma, pleomorphic liposarcoma, and extraskeletal osteosarcoma, respectively); these critical diagnostic features may be limited in extent. (5) Apply immunohistochemistry judiciously, after generating a differential diagnosis; always exclude metastatic sarcomatoid carcinoma and melanoma before diagnosing a pleomorphic sarcoma. This review will present an approach to the diagnosis of pleomorphic sarcomas, emphasizing differential diagnosis and the application of ancillary studies (immunohistochemistry and FISH), when relevant.

A primary extraskeletal osteosarcoma of the mesentery: a case report

Extraskeletal osteosarcoma is a rare and invasive malignancy, typically located in the soft tissue without attachment to the skeleton. The present study reports a case of a primary mesenteric extraskeletal osteosarcoma of a 71-year-old woman. The patient complained of an incomplete defecation. Colonoscopy showed an ulcer with impression of external compression of the sigmoid. An additional abdominal computed tomography (CT) scan revealed a large, almost completely calcified, mass in the left lower abdomen causing hydronephrosis of the left kidney. The patient underwent surgery and the mass was resected completely. The histopathological diagnosis was a primary abdominal extraskeletal osteosarcoma arising from the mesocolon with local invasion of the sigmoid. She was in follow-up without adjuvant chemo- or radiotherapy. Five months after initial surgery the tumor recurred with widespread peritoneal metastasis.

Extraskeletal osteosarcoma: A large series treated at a single institution

Purpose: This study is to present a large cohort of extraskeletal osteosarcoma (ESOS) and evaluate prognostic factors and treatment options. Methods: Medical records were reviewed retrospectively for 41 patients with extraskeletal osteosarcoma that was diagnosed by pathology, and treated at our institution between 1960 and 2016. Kaplan-Meier analysis and Cox proportional hazards regression were used to identify variables that affect survival outcomes. Results: 41 patients were identified from 952 osteosarcomas. 32 patients had non-metastatic disease. Prognostic factors were identified by univariate analysis and multi-variate analysis. Surgery (p<0.001), and surgery type (p<0.001) both were shown to significantly affect overall survival (OS). Chemotherapy and radiation therapy (RT) did not show any significant effect on OS, local recurrence, or progression free survival as a whole. However for patients who had incomplete resection with residual tumor RT improved OS (p=0.03). The survival curve for ESOS follows more closely that of non-rhabdomyosarcoma soft tissue sarcomas (NRSTS). Conclusions: ESOS is a very rare tumor. Attempt to achieve wide resection is the treatment of choice. However for patients who are not able to achieve complete resection, RT may improve OS. The behavior of ESOS more closely follows that of NRSTS than osteosarcoma of the bone.

Osteosarcoma, Chondrosarcoma, and Chordoma

Osteosarcoma (OS), chondrosarcoma, and chordoma are characterized by multiple challenges to the investigator, clinician, and patient. One consequence of their rarity among sarcomas, as well as their biologic and clinical heterogeneity, is that management guidelines are inadequate to inform the range of individual patient-treatment decisions from diagnosis, approaches to surgery, chemotherapy, radiotherapy, treatment of recurrence, palliative care, and quality of survivorship. Of high-grade sarcomas, OSs are among the most curable, with more than two-thirds of patients with localized disease likely to achieve long-term survival. Neoadjuvant chemotherapy comprising cisplatin, doxorubicin, and methotrexate with intercalated surgery is the standard of care for resectable OS in those younger than 40 years. Outcomes for OS presenting with unresectable metastases or recurrent disease, or in those older than 40 years are generally poor. Overall results have improved little for all patients with OS, and new treatments are needed. Surgical resection remains the cornerstone of management for chondrosarcoma and chordoma. However, the application of new biologic insights to therapeutic development indicates that improved treatments may soon be routine for patients with chondrosarcoma and chordoma for whom surgery alone is inadequate. For all these uncommon diseases, patients should be offered specialist expert care delivered by experienced multidisciplinary teams in high-volume centers.

Extraskeletal osteosarcoma of the orbit: A clinicopathologic case report and review of literature

Primary extraskeletal osteosarcoma (EOS) is an extremely rare malignancy. In this report, the clinical course of a 32-year-old man presenting with proptoses is described. Medical history included Hirschsprung disease (HD), horseshoe kidney, azoospermia, and vertebral anomalies. Imaging of the orbit showed an oval, well-defined heterogeneous mass adjacent to the lateral wall of the orbit. The patient underwent a lateral orbitotomy and complete excision of the mass. The mass was not attached to the bone. Histopathologic and immunohistochemical examination confirmed the diagnosis of an EOS. The patient received chemotherapy and radiotherapy and is free of the disease 3 years after the diagnosis. Genetic screening showed no mutations for both the RET proto-oncogene for HD and the p53 tumor suppressor gene for osteosarcoma.

Giant abdominal osteosarcoma causing intestinal obstruction treated with resection and adjuvant chemotherapy

Extraskeletal osteosarcoma (ESOS) is an uncommon tumor that accounts for 1% of all soft tissue sarcomas and 4% of all osteosarcomas. Its presentation may be atypical, while pain has been described as the most common symptom. Radiological findings include a large mass in the soft-tissues with massive calcifications, but no attachment to the adjacent bone or periosteum. We present the case of a 73-year-old gentle man who presented with a palpable, tender abdominal mass and symptoms of bowel obstruction. Computer tomography images revealed a large space-occupying heterogeneous, hyper dense soft tissue mass involving the small intestine. Explorative laparotomy revealed a large mass in the upper mesenteric root of the small intestine, measuring 22 cm × 12 cm × 10 cm in close proximity with the cecum, which was the cause of the bowel obstruction. Pathology confirmed the diagnosis of an ESOS. ESOS is an uncommon malignant soft tissue tumor with poor prognosis and a 5-year survival rate of less than 37%. Regional recurrence and distant metastasis to lungs, regional lymph nodes and liver can occur within the first three years of diagnosis in a high rate (45% and 65% respectively). Wide surgical resection of the mass followed by adjuvant chemotherapy or radiotherapy has been the treatment of choice.

Extraskeletal osteosarcoma: A European Musculoskeletal Oncology Society study on 266 patients

PURPOSE

Prognosis of extraskeletal osteosarcoma (ESOS) is reported to be poorer than that of skeletal osteosarcoma. This multicenter retrospective study aimed to evaluate factors influencing ESOS prognosis.

PATIENTS AND METHODS

Members of the European Musculoskeletal Oncology Society (EMSOS) submitted institutional data on patients with ESOS.

RESULTS

Data from 274 patients treated from 1981 to 2014 were collected from 16 EMSOS centres; 266 patients were eligible. Fifty (18.7%) had metastases at diagnosis. Of 216 patients with localised disease, 211 (98%) underwent surgery (R0 = 70.6%, R1 = 27%). Five-year overall survival (OS) for all 266 patients was 47% (95% CI 40-54%). Five-year OS for metastatic patients was 27% (95% CI 13-41%). In the analysis restricted to the 211 localised patients who achieved complete remission after surgery 5-year OS was 51.4% (95% CI 44-59%) and 5-year disease-free survival (DFS) was 43% (95% CI 35-51%). One hundred twenty-one patients (57.3%) received adjuvant or neoadjuvant chemotherapy and 80 patients (37.9%) received radiotherapy. A favourable trend was seen for osteosarcoma-type chemotherapy versus soft tissue sarcoma-type (doxorubicin ± ifosfamide) regimens. For the 211 patients in complete remission after surgery, patient age, tumour size, margins and chemotherapy were positive prognostic factors for DFS and OS by univariate analysis. At multivariate analysis, patient age (≤40 years versus >40 years) (P = 0.05), tumour size (P = 0.0001) and receipt of chemotherapy (P = 0.006) were statistically significant prognostic factors for survival.

CONCLUSION

Patient age and tumour size are factors influencing ESOS prognosis. Higher survival was observed in patients who received perioperative chemotherapy with a trend in favour of multiagent osteosarcoma-type regimen which included doxorubicin, ifosfamide and cisplatin.

Subcutaneous extraskeletal osteosarcoma of the forearm: a case report and review of the literature

Extraskeletal osteosarcoma (ESOS) originating in the subcutaneous tissue is a rare occurrence, accounting for less than 10 % of ESOS cases. Osteosarcoma of extraskeletal origin accounts for approximately 2-4 % of all osteosarcomas, and 1 % of soft tissue sarcomas. We report a case of an 80-year-old female with an isolated primary subcutaneous tumor of the forearm. After imaging, surgical excision, and pathological analysis, the diagnosis of a subcutaneous osteosarcoma was made. This report documents the clinical and pathological findings of subcutaneous ESOS in this case, along with a review of previous cases of subcutaneous ESOS.

The associations of vascular endothelial growth factor gene polymorphisms with susceptibility to osteosarcoma: evidence from a meta-analysis

Several studies have investigated the associations of the vascular endothelial growth factor (VEGF) gene polymorphisms with the susceptibility to osteosarcoma, while their conclusions are conflicting. This meta-analysis was performed to provide a comprehensive assessment on those associations. Electronic bibliographic databases were searched for potential studies focused on the relationship between VEGF polymorphisms and the susceptibility to osteosarcoma on 10 December 2015. Pooled odds ratios with 95% confidence intervals were conducted to assess the associations. After strict screening process, six articles consisted of 1220 osteosarcoma patients and 1576 controls were selected. The pooled results suggested that VEGF-2578C/A polymorphism was significantly associated with osteosarcoma risk in all genetic models as well as VEGF-634G/C polymorphism. When it came to VEGF+936C/T polymorphism, we detected significant associations under allele contrast, heterozygote, dominant and recessive models. As to VEFG-460T/C polymorphism, significant associations were demonstrated in allele contrast and heterozygote models. With regard to VEGF-1156G/A polymorphism, significant association was observed only in alleles contrast model. However, there was no significant association between VEGF-1612G/A polymorphism and risk of osteosarcoma. This meta-analysis suggests that these polymorphisms comprised of VEGF-2578C/A, VEGF-1156G/A, VEGF+936C/T, VEGF-634G/C and VEGF-460T/C are associated with osteosarcoma risk in Chinese Han population.

Primary Cardiac Osteosarcoma

BACKGROUND

Primary cardiac osteosarcoma is extremely rare. There is no cohort study on such tumours to date. The aim of this study is to investigate the clinical characteristics and outcome patterns of such tumours.

METHODS

A thorough literature review was performed, and all relevant clinical items were collected. A total of 53 cases of primary cardiac osteosarcoma were enrolled in this study, including 25 males and 28 females.

RESULTS

The age at diagnosis ranged from 14 to 77 years with a mean age of 43.6 years. The clinical manifestations, imaging features, and laboratory tests of the primary cardiac osteosarcomas were similar to other types of primary cardiac tumours. Sex, tumour size and adjunctive chemo-radiotherapy were found to affect the overall survival pattern.

CONCLUSIONS

The present study may provide an effective consultation for the diagnosis and treatment of this tumour.

Extraskeletal osteosarcoma of the hand: the role of marginal excision and adjuvant radiation therapy

BACKGROUND

Extraskeletal osteosarcoma of the hand is rare, and its optimal modality of local control is not currently known.

METHODS

A literature search was performed to identify studies that describe the treatment and outcomes of extraskeletal osteosarcoma. A second literature search was performed to identify studies that describe the treatment and outcomes of extraskeletal osteosarcoma of the hand specifically.

RESULTS

The role of adjuvant radiation for extraskeletal osteosarcoma is not well defined. All cases in the literature describing treatment of extraskeletal osteosarcoma of the hand utilized amputation, and none of the patients described received radiation therapy. However, there are multiple reports showing excellent local control, minimal toxicity, and superior functional outcome with limb conservation and radiation rather than amputation of the hand in pediatric and adult soft tissue sarcoma.

CONCLUSION

For extraskeletal osteosarcoma of the hand, we recommend a treatment approach with the goal of preservation of form and function using limb-sparing surgery and planned postoperative radiation.

Should High-grade Extraosseous Osteosarcoma Be Treated With Multimodality Therapy Like Other Soft Tissue Sarcomas?

BACKGROUND

Extraosseous osteosarcoma is rare, and the most appropriate therapy is unclear because there are few studies regarding its treatment. The effectiveness of radiation and chemotherapy remains uncertain owing to conflicting results in previous reports.

QUESTIONS/PURPOSES

To review our experience with contemporary multimodality treatment, we asked: (1) What is the disease-specific survival and local relapse-free survival? (2) Does American Joint Commission on Cancer (AJCC) stage, tumor size, or location relate to disease outcome? (3) Does radiation therapy improve local control or survival? (4) Do doxorubicin and ifosfamide improve local control or survival?

METHODS

Between 1990 and 2012, we treated 40 patients for localized, high-grade extraosseous osteosarcoma. In this retrospective study, we could determine the status of 36 patients (90%) either to death or for a minimum of 24 months of followup; four (10%) were lost to followup before 24 months. There were 11 patients with AJCC Stage IIA and 25 with Stage III disease. All patients underwent wide surgical excision. Of the patients with Stage IIA disease, four received radiation and none received chemotherapy. Of the patients with Stage III disease, six received radiation, seven were treated with chemotherapy, and six received radiation and chemotherapy. During the study period, high-dose doxorubicin and ifosfamide was the preferred chemotherapy regimen for patients younger than 60 years with normal cardiac and renal function. Local relapse-free survival and disease-specific survival were determined by Kaplan-Meier analysis using a prospectively maintained institutional database supplemented by information from the institutional tumor registry. The Cox proportional hazard model was used to determine the effect of various factors on local recurrence and patient survival.

RESULTS

At 5 years, local relapse-free survival was 47% (95% CI, 27%-64%), and disease-specific survival was 53% (95% CI, 35%-68%). In multivariate analysis, AJCC stage, which depends on tumor size, was the strongest predictor of local relapse-free survival (hazard ratio [HR] = 0.17, p = 0.02), while tumor depth was the best predictor of disease-specific survival (HR = 5.6, p = 0.02). Radiation improved local relapse-free survival (HR = 0.30, p = 0.03) but not disease-specific survival in multivariate analysis. A regimen of doxorubicin and ifosfamide was associated with better local relapse-free survival for patients with Stage III disease (HR = 0.16, p = 0.04) but not disease-specific survival (HR = 0.32, p = 0.08).

CONCLUSIONS

With the limited number of patients in our study, it appears that extraosseous osteosarcoma behaves differently than osteosarcoma of bone. Multimodality treatment that includes doxorubicin and ifosfamide-based chemotherapy, radiation, and surgery may be a valid therapeutic strategy for Stage III disease, but larger, prospective studies will be needed to verify our preliminary observations.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The molecular landscape of extraskeletal osteosarcoma: A clinicopathological and molecular biomarker study

Extraskeletal osteosarcoma (ESOSA) is a rare soft tissue neoplasm representing <5% of osteosarcomas and <1% of all soft-tissue sarcomas. Herein, we investigate the clinicopathological and molecular features of ESOSA and explore potential parameters that may affect outcome. Thirty-two cases were retrieved and histomorphology was reviewed. Clinical history and follow-up were obtained through electronic record review. DNA from formalin-fixed paraffin-embedded (FFPE) tissue was extracted and processed from 27 cases. Genome-wide DNA copy number (CN) alterations and allelic imbalances were analyzed by single nucleotide polymorphism array using Affymetrix OncoScan FFPE Assay. Massive high-throughput deep parallel sequencing was performed using a customized panel targeting 410 cancer genes. Log rank, Fisher's exact test and Cox proportional hazards were used for statistical analysis. In this series of 32 patients (male n = 12, female n = 20), the average age was 66 years (19-93) and median follow up was 24 months (range 6-120 months). Frequent genomic alterations included CN losses in tumour suppressor genes including CDKN2A (70%), TP53 (56%) and RB1 (49%). Mutations affecting methylation/demethylation, chromatin remodeling and WNT/SHH pathways were identified in 40%, 27%, and 27%, respectively. PIK3CA and TERT promoter variant mutations were identified in 11% of the cases. Cases harbouring simultaneous TP53 and RB1 biallelic CN losses were associated with worse overall survival and local recurrence (p = 0.04, p = 0.02, respectively). CDKN2A losses and positive margins were also associated with worse overall survival (p = 0.002; p = 0.03, respectively). Our findings suggest that age above 60, positive margin status, simultaneous biallelic TP53 and RB1 losses and CDKN2A loss are associated with a worse outcome in ESOSA. Comparison between conventional paediatric osteosarcoma and ESOSA shows that, while both share genetic similarities, there are notable dissimilarities and mechanistic differences in the molecular pathways involved in ESOSA.

Extra skeletal osteosarcoma of gall bladder: A case report

Extraskeletal osteosarcoma is a rare malignant soft tissue tumor. At open cholecystectomy performed for gallstones, a 45-year-old woman was found to have extraskeletal osteosarcoma on histopathological examination. 1 year after surgery, the patient is symptom free and all imaging studies are normal. After multidisciplinary discussion it was decided to give no further treatment. The patient was asked to follow up three monthly. Although osteosarcoma has rarely been reported at other extraskeletal sites, this appears to be the third case of a primary tumor in the gallbladder.

Long-term response of gemcitabine plus docetaxel chemotherapy regimen for extraskeletal osteosarcoma: A case report

Extraskeletal osteosarcomas (EOSs) are rare variants of primary osteosarcoma of the bone, and are defined as sarcomas located in the soft tissues and characterized by osteoid production. EOS exhibits distinctive demographic, imaging and prognostic features compared with osteosarcoma of bone origin. The available data are contradictory with regard to the use of chemotherapy regimens in the management of EOS. The present study describes a case of EOS that progressed following two lines of therapy oriented to soft-tissue and bone sarcoma histology, respectively. As a gemcitabine-docetaxel combination schedule has demonstrated synergistic activity against bone and soft-tissue sarcoma histologies, this chemotherapy regimen was selected as salvage therapy. The treatment was well-tolerated and induced a long lasting partial response for ~14 months. To the best of our knowledge, this is the first report involving the clinical use of this combination regimen for the treatment of EOS. Furthermore, as demonstrated in this report, EOS may maintain relative chemosensitivity, indicating the potential to control advanced disease in the long term and to plan subsequent chemotherapy regimens.

Outcome following treatment of soft tissue and visceral extraskeletal osteosarcoma in 33 dogs: 2008-2013

Extraskeletal osteosarcoma (EOS) is a rare, highly malignant mesenchymal neoplasm arising from viscera or soft tissues characterised by the formation of osteoid in the absence of bone involvement. Owing to the rarity of these neoplasms very little information exists on treatment outcomes. The purpose of this study was to describe the outcome following surgical treatment of non-mammary and non-thyroidal soft tissue and visceral EOS in dogs. Thirty-three dogs were identified; the most common primary tumour site was the spleen. Dogs that had wide or radical tumour excision had longer survival times compared with dogs that had only marginal tumour excision performed [median survival time of 90 days (range: 0-458 days) versus median survival time of 13 days (range: 0-20 days)]. The use of surgery should be considered in the management of dogs with non-mammary and non-thyroidal soft tissue and visceral EOS.

Clinical Features and Outcomes Differ between Skeletal and Extraskeletal Osteosarcoma

Background. Extraskeletal osteosarcoma (ESOS) is a rare subtype of osteosarcoma. We investigated patient characteristics, overall survival, and prognostic factors in ESOS. Methods. We identified cases of high-grade osteosarcoma with known tissue of origin in the Surveillance, Epidemiology, and End Results database from 1973 to 2009. Demographics were compared using univariate tests. Overall survival was compared with log-rank tests and multivariate analysis using Cox proportional hazards methods. Results. 256/4,173 (6%) patients with high-grade osteosarcoma had ESOS. Patients with ESOS were older, were more likely to have an axial tumor and regional lymph node involvement, and were female. Multivariate analysis showed ESOS to be favorable after controlling for stage, age, tumor site, gender, and year of diagnosis [hazard ratio 0.75 (95% CI 0.62 to 0.90); p = 0.002]. There was an interaction between age and tissue of origin such that older patients with ESOS had superior outcomes compared to older patients with skeletal osteosarcoma. Adverse prognostic factors in ESOS included metastatic disease, larger tumor size, older age, and axial tumor site. Conclusion. Patients with ESOS have distinct clinical features but similar prognostic factors compared to skeletal osteosarcoma. Older patients with ESOS have superior outcomes compared to older patients with skeletal osteosarcoma.

Extraskeletal osteosarcoma arising from the pleura

A 37-year-old woman was referred to our institution for further management of a mass lesion located in the thoracic cavity. The mass had grown by more than 10 cm over the course of a year and was initially considered to be a scar from previous pulmonary tuberculosis at another hospital. The patient had complained of left-sided flank pain for a year and experienced dyspnea for one month. Chest radiography and chest computed tomography revealed an irregular-shaped mass in the left mid to lower pleural cavity. The mass was widely excised through left thoracotomy. Pathologic examination of the biopsy specimen revealed a malignant spindle cell tumor, which consisted of components of osteosarcoma, pleomorphic sarcoma, and leiomyosarcoma. The patient underwent adjuvant chemotherapy and has been doing well without any evidence of recurrence for 14 months.

Large retroperitoneal low-grade extraskeletal osteosarcoma

Low-grade extraskeletal osteosarcoma is an extremely rare neoplasm with only nine cases reported in the literature, in which only one case involved the retroperitoneum. Tendency to dedifferentiate as well as recur with high-grade variant is known and management principles are not well defined, necessitating a continuous review of literature. We report management of the largest such retroperitoneal tumour (18.0 cm × 18.3 cm × 17.8 cm) in a 38-year-old man, which was treated with surgery followed by six cycles of cisplatin (90 mg/m(2) days 1 and 2) and doxorubicin (75 mg/m(2) day 3), cycled every 3 weeks (with granulocyte colony stimulating factor support as necessary). The patient is disease free after 3 years of follow-up.

Analysis of outcomes in extraskeletal osteosarcoma: a review of fifty-three cases

BACKGROUND

Extraskeletal osteosarcoma is a rare soft-tissue sarcoma about which little is known. The objectives of this study were to describe the clinical features and natural history of extraskeletal osteosarcoma and to investigate factors affecting outcomes.

METHODS

A retrospective review of a prospectively maintained database of patients diagnosed with soft-tissue sarcoma was conducted. Patients with pathologically confirmed extraskeletal osteosarcoma from 1982 to 2012 were identified and were included in the analysis. Medical records were reviewed for clinical features, treatment, and outcomes.

RESULTS

Fifty-three patients were identified from the database: forty-two presented with localized disease, two presented with metastatic disease, and nine presented with recurrent (local and/or distant) disease. The median patient age at diagnosis was sixty-four years, with a median follow-up time of thirty-four months (range, one to 290 months) for survivors. Of the fifty-three patients who were identified, forty-one had lesions in the extremities, fifty-one had high-grade lesions, forty had lesions >5 cm, and forty-two had deep lesions. For patients presenting with localized disease, the median survival was 45.8 months with a three-year cumulative incidence of death due to disease of 39%. All patients with localized disease were managed with surgical resection of the primary tumor: nineteen with surgery only, ten with adjuvant radiation, five with adjuvant chemotherapy, and eight with both radiation and chemotherapy. Eighteen patients relapsed: two patients had local recurrences, ten patients had distant metastases, and six patients had local recurrences and distant metastases. In log-rank analysis, patients with superficial tumors and negative margins at resection had a higher three-year event-free survival. No significant association of disease-specific or event-free survival was found with the addition of radiation, chemotherapy, or both to surgery.

CONCLUSIONS

For patients presenting with localized extraskeletal osteosarcoma, three-year event-free survival was higher for patients with superficial tumors and negative margins at resection. Radiation and chemotherapeutic treatment were not associated with a lower incidence of death due to disease or a longer event-free survival.