Malignant Soft Tissue Research Articles

Post-traumatic Pain: Think of Circumscribed Myositis Ossificans

Myositis ossificans is a benign condition, essential to know because the presence of ossifications of the soft tissues adjacent to the bone, always makes one fear a neoplastic localization in a young patient. We report in this study a rare case of traumatic circumscribed myositis ossificans of the thigh. Imaging plays an important role in the positive diagnosis, the differential diagnosis and the follow-up of the characteristic three-phase evolution of MOC. However, this pseudotumor may appear clinically and radiologically as a malignant tumor, a thorough knowledge of clinical and morphological study is necessary to differentiate this lesion from a soft tissue malignancy.

Is bipolar hemiarthroplasty an appropriate type of hip articulation following proximal femoral or total femoral resections for musculoskeletal malignancies?

Different approaches are applied for reconstruction in patients with a musculoskeletal malignancy which require a proximal femoral or total femoral resection. We aimed to evaluate the treatment outcomes of patients who underwent a proximal femoral or total femoral resection due to bone and soft tissue tumors and had an endoprosthetic reconstruction by a bipolar hemiarthroplasty type of hip articulation. We retrospectively identified 133 patients who underwent a proximal femoral or total femoral endoprosthetic replacement after resection of a bone or soft tissue malignancy. There were 74 male and 59 female patients, with a mean age of 55.02 ± 16.92years (range 11-84years) and a median follow-up of 24.47 ± 24.45months (range 6-164months). Patient demographics, surgical, and oncological data were recorded. Acetabular wear was measured using the classification proposed by Baker. Functional assessment was performed using the Musculoskeletal Tumor Society (MSTS) functional score. There was no statistically significant difference among primary diagnostic groups in terms of gender, prosthesis type, trochanter major resection, local recurrence, complication/revision rate, and MSTS Score (p > 0.05, for each parameter). On the other hand, a statistically significant difference was detected in terms of degree of acetabular erosion among diagnostic groups (p < 0.001); the acetabular erosion rate (AER) was found to be lower in patients with metastatic carcinoma than in patients with a diagnosis of primary bone or soft tissue sarcoma. The univariable analysis revealed that the effect of age, primary diagnosis, localization, follow-up time, and presence and number of distant organ metastasis variables on AER were found to be statistically significant (p = 0.018, p = 0.035, p = 0.002, p = 0.007, p = 0.031, p = 0.040, respectively). In patients who undergo a proximal femoral or a total femoral resection due to a musculoskeletal tumor, bipolar hemiarthroplasty is an adequate type of hip articulation method, since it does not affect the revision requirements and functional outcomes of patients with acetabular erosion.

Surgical Approaches to Neuroblastoma: Review of the Operative Techniques.

Neuroblastoma (NB) is the most commonly occurring soft-tissue malignancy of childhood. Surgery plays an important role in multidisciplinary treatment and its principal aim is a local control of the disease, respecting the integrity of the surrounding structures. There is no unanimous consensus on the best surgical technique, and the operative approach largely depends on the anatomical location and the extension of the mass. To have a complete overview of the different type of treatment, we made a review of the literature from the last twenty years of all the surgical approaches applied for NBs resection, accordingly to the anatomical site.

Prevalence of Symptomatic Venous Thromboembolism in Patients with Malignant Bone and Soft Tissue Tumors Undergo Surgery without Chemoprophylaxis

Background: The prevalence and risk factors of venous thromboembolism (VTE) in malignant bone and soft tissue tumor patients that undergo surgery is reported in many studies. However, there is lack of studies on the patients without chemoprophylaxis. Objective: To evaluate the prevalence and risk factors for VTE after surgery in malignant bone and soft tissue tumor patients without chemoprophylaxis Materials and Methods: A retrospective medical chart review identified 260 cases of malignant bone and soft tissue tumor operated between 2008 and 2017. Official diagnostic reports were reviewed from the Picture Archiving and Communication System (PACs). The incidence of VTE and its risk factors were assessed using Chi-square test, t-test, and binary logistic regression. Results: The overall prevalence of symptomatic VTE was 0.8% (2/260 patients), all of which had PE. No fatal VTE was detected. Asymptomatic pulmonary embolism (PE) was identified in two patients (0.8%) Mean follow up interval of the available data was 9.5 (3 to 36) months. No significant risk factor was found. Conclusion: The authors found that patients with malignant bone and soft tissue tumors that underwent surgery without chemoprophylaxis in the authors’ center had lower prevalence of VTE when compared to most previous studies whose patient received chemoprophylaxis. Keywords: Venous thromboembolism, Sarcoma, Cancer, Deep vein thrombosis, Pulmonary embolism, Thromboprophylaxis, Chemoprophylaxis

Neurofibroma intraósseo versus schwannoma, importância do diagnóstico diferencial histológico no diagnóstico definitivo: Relato de caso

As neoplasias de origem neurais representam 8% e 12% de todas as neoplasias de tecidos moles malignas e benignas, respectivamente. Nesse conjunto estão inseridos os tumores da bainha do nervo periférico (TBNP), um grupo relativamente raro de doenças que são classificadas de acordo com as características específicas de diferenciação, componentes celulares e matriz extracelular. Neurofibroma e schwannoma são exemplos de lesões pertencentes a esse grupo. O objetivo desse estudo é apresentar um caso clínico de uma paciente, sexo feminino, 60 anos de idade, diagnosticada com lesão central na região de corpo mandibular direito. A lesão foi descoberta após exame de rotina para reabilitação protética e, após biopsia incisional, obteve-se diagnóstico inicial de schwannoma. O tratamento proposto foi uma ressecção marginal, por meio da instalação de placa de reconstrução de 2,4mm e enucleação da lesão. Uma biopsia excisional foi então solicitada onde se obteve como diagnóstico final neurofibroma. A paciente apresentou resposta satisfatória ao tratamento, sem sinais de recidiva. Embora o diagnóstico decisivo de neurofibroma seja baseado em achados histológicos, lesões como schwannoma devem ser incluídas como diagnóstico diferencial histológico, o que pode dificultar o diagnóstico definitivo. Nesse sentido, características peculiares do schwannoma e neurofibroma, seus comportamentos imunoistoquímicos e suas semelhanças são necessários para traçar suas repercussões no estabelecimento do diagnóstico. Ainda que não haja diferença no tratamento, tais lesões podem estar associadas a síndromes diferentes, o que torna necessária sua diferenciação final, especificamente para os casos em que haja dúvida.

Synovial Sarcoma Oncogenesis Revealed by Single-Cell Profiling

Synovial sarcoma is a soft tissue malignancy driven by the SS18-SSX fusion oncoprotein. In Nature Medicine, Jerby-Arnon et al. present a single-cell dataset for synovial sarcoma that reveals a novel 'core oncogenic program' driven by SS18-SSX, with implications for treatment strategies based on epigenetics, cell-cycle control, and immune augmentation.

Extremity Pain

Key Points Fever, weight loss, rash, diaphoresis, or gastrointestinal symptoms should raise suspicion for systemic diseases such as septic arthritis or autoimmune disease.If patients have undergone recent medication treatment, vaccination, or viral exposure, or have traveled, consider serum sickness–like illness, aseptic necrosis, or viral myositis or arthritis.Pain that disrupts only unpleasant activities (eg, school) or occurs in a nonanatomic distribution should prompt consideration of a functional disorder.Be sure to examine proximally and distally to the site of pain, as referred pain is common in children.Screening laboratory studies should be performed when history and physical examination do not yield definitive diagnosis or suggest systemic or infectious disease, or if pain lasts beyond expected duration.The Ottawa criteria to guide radiograph imaging decisions have been validated for ankle and knee pain in children older than 5 years. Magnetic resonance imaging is most useful if assessment for joint and soft tissue disease, osteomyelitis, and malignancy is needed, although bone scan may be used instead if area of concern cannot be sufficiently narrowed by examination or if the need for sedation is prohibitive.

Diagnostic Immunohistochemistry of Soft Tissue and Bone Tumors: An Update on Biomarkers That Correlate with Molecular Alterations.

The diagnosis of benign and malignant soft tissue and bone neoplasms is a challenging area of surgical pathology, due to the large number, rarity, and histologic diversity of tumor types. In recent years, diagnosis and classification has been aided substantially by our growing understanding of recurrent molecular alterations in these neoplasms. Concurrently, the role of diagnostic immunohistochemistry has also expanded, with the development of numerous biomarkers based on underlying molecular events. Such biomarkers allow us to infer the presence of these events and can therefore substitute for other ancillary molecular genetic techniques (e.g., fluorescence in situ hybridization, polymerase chain reaction, and next-generation sequencing). In this review, we discuss a range of biomarkers currently available for these neoplasms, highlighting the accuracy, staining characteristics, and interpretation pitfalls of each antibody. These include immunohistochemical antibodies that represent reliable surrogates for the detection of gene fusions (e.g., STAT6, CAMTA1, FOSB, DDIT3) and more recently described breakpoint-specific antibodies (e.g., SS18-SSX, PAX3/7-FOXO1). Additionally, discussed are markers that correlate with the presence of gene amplifications (e.g., MDM2, CDK4), deletions (e.g., SMARCB1, SMARCA4), single nucleotide variants (e.g., G34W, K36M), aberrant methylation (H3K27me3), and increased expression as discovered through gene expression profiling (e.g., MUC4, DOG1, ETV4, NKX2.2, NKX3.1).

Diagnosis and Prognosis of Retroperitoneal Liposarcoma: A Single Asian Center Cohort of 57 Cases.

Background Liposarcoma is a soft tissue malignancy, commonly observed in the extremities. However, retroperitoneal liposarcoma is seldom reported and its diagnosis is frequently neglected. This study aims to present the clinical characteristics, diagnosis, and prognosis of five liposarcoma subtypes and report our experience of patient treatment. Methods We conducted a single-center noninterventional retrospective study of 57 retroperitoneal liposarcoma patients admitted to Peking Union Medical College Hospital (PUMCH, Beijing, China) between July 2011 and December 2019. We collected and analyzed their demographic, clinical, imaging, histological, therapeutic, and prognostic data over a mean 4.5-year follow-up period. Results Twenty-five (44%) patients were asymptomatic prior to diagnosis, with abdominal distension as the chief complaint in 18 (32%) patients and abdominal pain observed in 16 (28%) patients. Masses were evaluated by computed tomography (n = 48, 84%) or ultrasound (n = 25, 44%). Laparotomy (n = 52, 91%) was the dominant therapeutic modality rather than laparoscopy (n = 5, 9%). All patients were treated with R0 resection except two patients who underwent R2 resection. We conducted regular follow-ups every six months after surgery for a mean duration of 4.5 years. Recurrence was experienced by 14 (25%) patients and a further 9 (16%) died during follow-up. Conclusions Abdominal distension and pain are chief complaints with liposarcoma. As the extremities are the main liposarcomas locations, the diagnosis of retroperitoneal liposarcoma is usually neglected. Since half of the patients are asymptomatic, timely diagnosis and treatment are highly dependent on regular ultrasound and computed tomography imaging. R0 resection is the key to retroperitoneal liposarcoma treatment. In comparison, patients who underwent R2 resection, which is considered a palliative treatment, had bad prognoses. Large, symptomatic dedifferentiated, and pleomorphic liposarcomas are more likely to have poor prognoses, while the prognosis for well-differentiated or myxoid liposarcoma is relatively good.

FOXF1 is required for the oncogenic properties of PAX3-FOXO1 in rhabdomyosarcoma.

The PAX3-FOXO1 fusion protein is the key oncogenic driver in fusion positive rhabdomyosarcoma (FP-RMS), an aggressive soft tissue malignancy with a particularly poor prognosis. Identifying key downstream targets of PAX3-FOXO1 will provide new therapeutic opportunities for treatment of FP-RMS. Herein, we demonstrate that Forkhead Box F1 (FOXF1) transcription factor is uniquely expressed in FP-RMS and is required for FP-RMS tumorigenesis. The PAX3-FOXO1 directly binds to FOXF1 enhancers and induces FOXF1 gene expression. CRISPR/Cas9 mediated inactivation of either FOXF1 coding sequence or FOXF1 enhancers suppresses FP-RMS tumorigenesis even in the presence of PAX3-FOXO1 oncogene. Knockdown or genetic knockout of FOXF1 induces myogenic differentiation in PAX3-FOXO1-positive FP-RMS. Over-expression of FOXF1 decreases myogenic differentiation in primary human myoblasts. In FP-RMS tumor cells, FOXF1 protein binds chromatin near enhancers associated with FP-RMS gene signature. FOXF1 cooperates with PAX3-FOXO1 and E-box transcription factors MYOD1 and MYOG to regulate FP-RMS-specific gene expression. Altogether, FOXF1 functions downstream of PAX3-FOXO1 to promote FP-RMS tumorigenesis.

Abstract PO042: Oncostatin M receptor as a therapeutic target of radioimmune therapy in metastatic synovial sarcoma

Abstract Synovial sarcoma is a soft tissue malignancy of the muscle that primarily affects adolescents. Due to it low incidence, little advancement has been made in the treatment of this cancer. With an overall survival rate of roughly 40%, the need for new treatments for synovial sarcoma is evident. Oncostatin M Receptor (OSMR) is a type I cytokine receptor and is overexpressed in metastatic synovial sarcoma. OSMR does not have high expression in normal tissues, making it an ideal target for cancer therapy. We hypothesize that by using an anti-OSMR monoclonal antibody conjugated to a radioactive Cu67 isotope, synovial sarcoma can be targeted at both primary and metastatic locations through systemic therapy. Copper67 is a beta radiation emitting isotope that is tissue damaging and able to induce cell death in cancer cells. By conjugating the chelating molecule p-SCN-Bn-NOTA to an anti-OSMR antibody, Cu67 was able to be captured to the antibody. Capture efficiency of Cu67 was measured after TLC separation and found to be 80% efficient. This data suggests that targeting OSMR through radioimmunotherapy (RIT) is a viable treatment and indicates further testing in animal models. Citation Format: Sarah Luelling, Matthew Kirkham, Jared Barrott. Oncostatin M receptor as a therapeutic target of radioimmune therapy in metastatic synovial sarcoma [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO042.

Rhabdomyosarcoma Presenting as Bilateral Cervical Lymphadenopathy in an Adult with Aberrant Expression of Cytokeratin and Synaptophysin: A Potentially Serious Diagnostic Pitfall

Rhabdomyosarcoma (RMS) is the most common soft tissue malignancy in children and adolescents. Its occurrence in patients more than 18 years of age is rare. Subtypes of rhabdomyosarcoma include embryonal RMS, alveolar RMS, pleomorphic RMS and spindle/sclerosing RMS.Herein, we report the case of a 42-year-old female patient who presented with bilateral cervical lymphadenopathy of two-month duration. Clinical and radiological examination showed no other significant lesions. Fine needle aspiration cytology and biopsy of lymph node showed diffusely arranged atypical round cells. The clinical findings and morphology pointed to a hematolymphoid malignancy. On immunohistochemical examination, the atypical cells were negative for CD45, CD20, CD3, PAX5 and CD30. The cells showed patchy moderate positivity for cytokeratin, focal weak positivity for synaptophysin and were negative for chromogranin, CD56 and TTF1. On further evaluation, patchy strong positivity for desmin, myogenin and myo D1 were noted. Correlating the morphology and immunoprofile, diagnosis of rhabdomyosarcoma was given.Multiple peripheral lymph node enlargement without an obvious primary lesion is a rare presentation of alveolar RMS, with only a few cases reported in literature. Unusual clinical presentation complicated with aberrant expression of epithelial markers may make the diagnosis of alveolar RMS difficult. This case demonstrates the importance of considering extensive differential diagnosis for neck masses with poorly differentiated morphology.

Sarcoma classification by DNA methylation profiling

Sarcomas are malignant soft tissue and bone tumours affecting adults, adolescents and children. They represent a morphologically heterogeneous class of tumours and some entities lack defining histopathological features. Therefore, the diagnosis of sarcomas is burdened with a high inter-observer variability and misclassification rate. Here, we demonstrate classification of soft tissue and bone tumours using a machine learning classifier algorithm based on array-generated DNA methylation data. This sarcoma classifier is trained using a dataset of 1077 methylation profiles from comprehensively pre-characterized cases comprising 62 tumour methylation classes constituting a broad range of soft tissue and bone sarcoma subtypes across the entire age spectrum. The performance is validated in a cohort of 428 sarcomatous tumours, of which 322 cases were classified by the sarcoma classifier. Our results demonstrate the potential of the DNA methylation-based sarcoma classification for research and future diagnostic applications.

Ewing Sarcoma/Peripheral Neuroectodermal Tumor of Bone and Soft Tissue in Infants: A Report from Children Cancer Hospital of Egypt

Introduction: Ewing sarcoma is an aggressive malignancy of bone and soft tissue. It is rare in children under age 5years. Ewing's sarcoma family tumors include classic Ewing’s sarcoma, primitive neuroectodermal tumour and Askin tumor ES is the second most common variety of primary bone cancer in adolescents and young adults. The treatment strategy for ES is characterized by multi-disciplinary collaboration between pediatric oncologists, medical oncologists, radiation oncologists, and orthopedic surgeons. Although the survival rate of ES patients has improved, their prognosis remains unsatisfactory, and the treatment of ES is still challenging specially in age group below 3 years. Patients and methods: A Retrospective study of children below 3 years with a diagnosis Ewing Sarcoma/PNET treated at our CCHE from July 2009 till December 2018. Results: A review of 46 patients with age ranged from 3 months to 3 years, Mean of age was 1.8. Primary site was Osseous and extraosseus in 23 infant patients for each. Main site was mainly axial in 28 cases (60.8%). Cases were treated according to COG protocol. Infantile Ewing sarcoma OS and EFS at 5-years OS were 75.5% and 66.7%. Conclusion: Patients below 3 years represent an unusually young age group. Conclusion: ES/PNET in age below 3 years is a unique age group with a different management and outcome.

Mediastinal Liposarcoma: Case Report and Literature Review

Liposarcomas (LS) are the second most common type of soft tissue malignancies in adults; they arise from mesenchymal cells and account for 1% of all adult cancers and 15% of all pediatric cancers. The site of origin can be from anywhere there is fat in the human body. LS are classified based on the primary site of origin, and mediastinal LS are extremely rare. When mediastinal neoplasms are stratified based on histology, they represent less than 1% of all mediastinal tumors. To date, less than 150 cases have been reported in the English literature. This article aims to present an unusual case of an extremely rare malignancy and perform a systematic review of the latest literature. In this report, our group is documenting the presentation, management, and outcome of a 65-year-old male patient with a massive anterior mediastinal primary LS. The tumor was displacing the mediastinum into the right chest, occupying most of the left chest, and pushing the diaphragm into the abdomen. Mediastinal liposarcomas are extremely rare malignancies and can prove to be challenging to diagnose and treat. Aggressive surgical treatment with R0 resection is the gold standard, however, tumor biology in many cases is associated with variable growth rates and encroachment of adjacent vital structures and blood vessels. When complex anatomical structures preclude an R0 resection, there is a high incidence of local recurrence. In cases where there is a high risk of recurrence, radiotherapy is indicated and chemotherapy has a more limited role.

Synchronous Renal Dedifferentiated Liposarcoma and Retroperitoneal Well-Differentiated Liposarcoma: A Case Report With Literature Review.

Liposarcoma is the most common soft tissue malignancy and usually occurs in the retroperitoneum or the extremities but rarely in the kidney. In this article, we report a case of a 71-year-old female patient who presented with abdominal lump and left flank pain for 1 month. An abdominal contrast-enhanced computed tomography scan demonstrated a 12 cm × 7 cm solid mass arising from the upper pole of left kidney and another 8 cm × 6 cm low-density retroperitoneal mass with fat density. Radical nephrectomy of the left kidney and resection of the retroperitoneal mass were performed. Surprisingly, pathological examination revealed a high-grade sarcoma (with minor lipomatous component) in the left kidney and a retroperitoneal well-differentiated liposarcoma. MDM2 gene amplification was identified by fluorescence in situ hybridization in both tumors, supporting final diagnosis of dedifferentiated liposarcoma of the kidney and well-differentiated liposarcoma of the retroperitoneum.

Second Primary Malignancy after Acute Promyelocytic Leukemia: A Population-Based Study.

Simple SummaryAcute promyelocytic leukemia (APL) is a rare and aggressive subtype of acute myeloid leukemia (AML). Since the introduction of all-trans-retinoic acid (ATRA) in APL management, the survival rate has increased substantially. However, there is evidence that retinoids might enhance tumor growth and the risk of secondary malignancies. The relationship between secondary cancer risk and APL treatment that includes ATRA is incompletely characterized. In this study, we investigated the risk factors associated with second primary malignancies after treatment of APL. Age ≥ 40 years at diagnosis of APL was significantly associated with an increased risk of second malignancies. Our findings suggest a potential carcinogenic role for ATRA in the salivary gland, liver, and soft tissue malignancies. Moreover, secondary tumors were significantly more frequent among patients with primary APL than in individuals with non-APL malignancies. Our finding suggests opportunities for surveillance for patients who completed treatment for APL.Acute promyelocytic leukemia (APL), is now highly curable with treatment approaches that include all-trans retinoic acid (ATRA). The high incidence of APL in the Hispanics suggests an association with genetic variants in this population. Information on second primary malignancies (SPMs) in patients with APL is limited. The Surveillance, Epidemiology, and End Results (SEER) database was used to interrogate whether the rate of SPMs in patients with APL was associated with ethnicity and/or ATRA treatment. Between 2000 and 2016, 116 cases of SPM were diagnosed among 4019 patients with APL. The mean age at diagnosis of primary APL was 53.9 years (±15.7 years), and the mean age at diagnosis of SPMs was 59.0 years (±14.5 years). Comparisons with 3774 APL survivors who did not develop SPMs revealed that age ≥40 years at diagnosis of APL (p < 0.001) and non-Hispanic white ethnicity (p = 0.025) were associated with SPMs in APL survivors. Salivary gland, liver, and soft tissue malignancies were significantly more common in patients with primary APL than in individuals with non-APL malignancies. A risk analysis comparing patients who had APL with patients who had non-APL AML suggests that SPMs after APL is associated with ATRA treatment. Therefore, patient follow-up after APL should focus on early diagnosis of SPMs.

Primary Pleural Angiosarcoma With Extensive And Rapid Metastasis To Brain And Bilateral Adrenal Glands

Abstract Casestudy: Angiosarcomas represent 1% of all soft tissue malignancies. Primary pleural angiosarcomas are aggressive and extremely rare. The etiology of pleural angiosarcoma is largely unknown but in the few reported cases it is associated with asbestos exposure. Common presenting symptoms are chest pain, cough, dyspnea, and weight loss. Localized tumors are generally resected, with other options including chemotherapy and radiotherapy. Limited literature describes this rare neoplasm’s metastatic potential and patterns. We present a 64-year-old male with shoulder pain and chronic cough. CT thorax showed a large 6.7 x 8 cm mass with central necrosis in the left upper lung invading the chest wall with partial destruction of the second and third ribs, and axillary adenopathy. Bilateral adrenal nodules were also identified. Histology of the adrenal lesion reveal sheets of infiltrative polygonal/round cells with large nuclei, prominent nucleoli and eosinophilic cytoplasm. Tumor cells were positive for CD31, CD34, FLI-1, AE1/AE3 and CK7 immunohistochemical stain, correlating with primary epithelioid angiosarcoma. Based on the patients new development of confusion, dizziness and ataxia, an MRI was performed showing multiple metastatic brain lesions. One month after initial presentation, the patient again presented with worsening symptoms. Work up showed enlargement of the bilateral adrenal masses, doubling of the brain lesions and an additional lesion posterior to the left kidney. This case shows the metastatic potential and pattern of an aggressive primary neoplasm that is not described in current literature. It also highlights the importance of timely intervention based on the rapid metastatic progression of primary pleural angiosarcomas.

Abstract 529: Oncostatin M receptor as a therapeutic target of radio-immune therapy in metastatic synovial sarcoma

Abstract Synovial sarcoma is a soft tissue malignancy of the muscle tissue which primarily affects adolescents. While it is a rare disease, little advancement has been made in the treatment of this cancer. With an overall survival rate of roughly 40%, the need for new treatments for synovial sarcoma is evident. Oncostatin M Receptor (OSMR) is a type I cytokine receptor and is overexpressed in metastatic synovial sarcoma. OSMR does not have high expression in normal tissues, making it an ideal target for cancer therapy. We hypothesize that by using an anti-OSMR monoclonal antibody conjugated to a radioactive Cu67 isotope, synovial sarcoma can be targeted at both primary and metastatic locations through systemic therapy. Copper 67 is a gamma radiation emitting isotope which is tissue damaging and able to induce cell death in cancer cells. By conjugating the chelating molecule p-SCN-Bn-NOTA to an anti-OSMR antibody, Cu67 was able to be captured to the antibody. Capture efficiency of Cu67 was measured through TLC and found to be 64 % efficient. Binding studies through Surface Plasmon Resonance (SPR) found that the conjugation did not interfere with the binding affinity of the antibody. This data suggests that targeting OSMR through radio-immune therapy is a viable treatment and indicates further testing in animal models. Citation Format: Sarah Luelling. Oncostatin M receptor as a therapeutic target of radio-immune therapy in metastatic synovial sarcoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 529.

Urgent distal pancreatectomy for intraperitoneal hemorrhage due to the spontaneous rupture of a pancreatic metastatic tumor from synovial sarcoma: a case report

BackgroundSynovial sarcoma is a soft tissue malignancy that frequently affects the extremities, adjacent to the large joints. Synovial sarcoma has a high rate of distant metastasis; however, pancreatic metastasis is extremely rare, and to our knowledge, there has been no report of bleeding due to spontaneous tumor rupture. This study reports the case of a patient with synovial sarcoma pancreatic metastasis causing tumor rupture and bleeding, which was successfully managed with emergent distal pancreatectomy.Case presentationA 27-year-old woman underwent extensive resection of the primary tumor and partial lung resection after chemotherapy for left femoral synovial sarcoma and multiple lung metastases 4 years prior. During the follow-up, a 35-mm tumor was noted in the pancreatic tail on abdominal computed tomography (CT), and no other distant metastases were detected via positron emission tomography CT. Laparoscopic distal pancreatectomy was scheduled for pancreatic metastasis of synovial sarcoma. However, before the scheduled pancreatectomy could be conducted, the patient visited the emergency department because of abdominal pain that occurred after consuming a small amount of alcohol, and CT showed ascites with high CT values and leakage of contrast media. She was diagnosed with intra-abdominal hemorrhage due to a ruptured metastatic pancreatic tumor, and an emergency operation was performed. In total, 1500 mL of blood was evacuated from the abdomen, and the bleeding pancreatic tail tumor was resected. Histopathological findings revealed synovial sarcoma metastasis and a ruptured tumor capsule, and tumor cells were observed in the hematoma. After discharge on postoperative day 18, the patient was carefully monitored and confirmed to be in relapse-free survival, without chemotherapy, at 6 months post-surgery.ConclusionsWhile the rate of tumor growth varies depending on the grade of the tumor, the possibility of rupture should be considered even in metastatic pancreatic tumors. In the case of pancreatic tumor rupture with stable circulation, radiological evaluation for oncology is necessary, and primary resection may be compatible with resectable cases.