Synovial Sarcoma Is Not Associated With a Higher Risk of Lymph Node Metastasis Compared With Other Soft Tissue Sarcomas

Soft tissue tumor imaging in adults: whole-body staging in sarcoma, non-malignant entities requiring special algorithms, pitfalls and special imaging aspects. Guidelines 2024 from the European Society of Musculoskeletal Radiology (ESSR)

OBJECTIVES

The revised European Society of Musculoskeletal Radiology (ESSR) consensus guidelines on soft tissue tumor imaging represent an update of 2015 after technical advancements, further insights into specific entities, and revised World Health Organization (2020) and AJCC (2017) classifications. This second of three papers covers algorithms once histology is confirmed: (1) standardized whole-body staging, (2) special algorithms for non-malignant entities, and (3) multiplicity, genetic tumor syndromes, and pitfalls.

MATERIALS AND METHODS

A validated Delphi method based on peer-reviewed literature was used to derive consensus among a panel of 46 specialized musculoskeletal radiologists from 12 European countries. Statements that had undergone interdisciplinary revision were scored online by the level of agreement (0 to 10) during two iterative rounds, that could result in 'group consensus', 'group agreement', or 'lack of agreement'.

RESULTS

The three sections contain 24 statements with comments. Group consensus was reached in 95.8% and group agreement in 4.2%. For whole-body staging, pulmonary MDCT should be performed in all high-grade sarcomas. Whole-body MRI is preferred for staging bone metastasis, with [18F]FDG-PET/CT as an alternative modality in PET-avid tumors. Patients with alveolar soft part sarcoma, clear cell sarcoma, and angiosarcoma should be screened for brain metastases. Special algorithms are recommended for entities such as rhabdomyosarcoma, extraskeletal Ewing sarcoma, myxoid liposarcoma, and neurofibromatosis type 1 associated malignant peripheral nerve sheath tumors. Satisfaction of search should be avoided in potential multiplicity.

CONCLUSION

Standardized whole-body staging includes pulmonary MDCT in all high-grade sarcomas; entity-dependent modifications and specific algorithms are recommended for sarcomas and non-malignant soft tissue tumors.

CLINICAL RELEVANCE STATEMENT

These updated ESSR soft tissue tumor imaging guidelines aim to provide support in decision-making, helping to avoid common pitfalls, by providing general and entity-specific algorithms, techniques, and reporting recommendations for whole-body staging in sarcoma and non-malignant soft tissue tumors.

KEY POINTS

An early, accurate, diagnosis is crucial for the prognosis of patients with soft tissue tumors. These updated guidelines provide best practice expert consensus for standardized imaging algorithms, techniques, and reporting. Standardization can improve the comparability examinations and provide databases for large data analysis.

Lymphadenectomy in the treatment of sarcomas - indications and technique

Sarcomas are a rare type of malignancy with limited treatment options so far. This analysis aimed to describe the impact of lymphadenectomy on treating sarcoma patients. Sarcomas characterized by lymphatic spread are rare. For this reason, lymphadenectomy is not a procedure that is performed frequently. However, there are histological subtypes that spread more frequently through lymphatic vessels, such as rhabdomyosarcoma (RMS), epithelioid sarcoma (ES), clear cell sarcoma (CCS), and angiosarcoma. On the other hand, synovial sarcoma (SS) is not characterized by an increased tendency to lymphogenous metastases. In our study, we focus on these subtypes of sarcomas. The relationship between lymphadenectomy results and the subsequent prognosis of the patients was investigated. Metastases in the lymph nodes are diagnosed synchronously with distant metastases or when the primary tumor is detected. At the same time, despite lymphadenectomy, sarcoma patients developed further distant metastases. Currently, lymphadenectomy is not a routinely recommended method of treatment for patients with sarcomas. Most often, its potential use is indicated in the case of epithelioid sarcoma, clear cell sarcoma, and rhabdomyosarcoma after a previous positive sentinel lymph node biopsy (SLNB) result. Multicenter randomized prospective clinical trials on the role of lymphadenectomy in the treatment of sarcomas are needed.

Histology-Tailored Approach to Soft Tissue Sarcoma

Soft tissue sarcomas are a diverse and heterogeneous group of cancers of mesenchymal origin. Each histological type of soft tissue sarcoma has unique clinical particularities, which makes them challenging to diagnose and treat. Multidisciplinary management of these rare diseases is thus key for improved survival. The role of surgery has been well established, and it represents the cornerstone curative treatment for soft tissue sarcomas. To date, local recurrence is the leading cause of death in low-grade sarcomas located at critical sites, and distant metastasis in high-grade sarcomas, regardless of the site of origin. Management must be tailored to each individual histologic type. We describe the most common types of extremity, trunk, abdominal, and retroperitoneal soft tissue sarcoma along with characteristics to consider for optimized management.

MRI of Soft-Tissue Tumors: What to Include in the Report

MRI serves as a critical step in the workup, local staging, and treatment planning of extremity soft-tissue masses. For the radiologist to meaningfully contribute to the management of soft-tissue masses, they need to provide a detailed list of descriptors of the lesion outlined in an organized report. While it is occasionally possible to use MRI to provide a diagnosis for patients with a mass, it is more often used to help with determining the differential diagnosis and planning of biopsies, surgery, radiation treatment, and chemotherapy (when provided). Each descriptor on the list outlined in this article is specifically aimed to assist in one or more facets of the overall approach to soft-tissue masses. This applies to all masses, but in particular sarcomas. Those descriptors are useful to help narrow the differential diagnosis and ensure concordance with a pathologic diagnosis and its accompanying grade assignment of soft-tissue sarcomas. These include a lesion's borders and shape, signal characteristics, and contrast enhancement pattern; the presence of peritumoral edema and peritumoral enhancement; and the presence of lymph nodes. The items most helpful in assisting surgical planning include a lesion's anatomic location, site of origin, size, location relative to a landmark, relationship to adjacent structures, and vascularity including feeding and draining vessels. The authors provide some background information on soft-tissue sarcomas, including their diagnosis and treatment, for the general radiologist and as a refresher for radiologists who are more experienced in tumor imaging. ©RSNA, 2024 See the invited commentary by Murphey in this issue.

Differentiation of benign and metastatic lymph nodes in soft tissue sarcoma

Lymph node metastasis (LNM) occurs in less than 5% of soft tissue sarcoma (STS) patients and indicates an aggressive course of disease. Suspicious lymph nodes (LN) in staging imaging are a frequent topic of discussion in multidisciplinary tumor boards. Predictive markers are needed to facilitate stratification and improve treatment of STS patients. In this study, 56 STS patients with radiologically suspicious and subsequently histologically examined LN were reviewed. Patients with benign (n = 26) and metastatic (n = 30) LN were analyzed with regard to clinical, laboratory and imaging parameters. Patients with LNM exhibited significantly larger short axis diameter (SAD) and long axis diameter (LAD) vs. patients with benign LN (median 22.5 vs. 14 mm, p < 0.001 and median 29.5 vs. 21 mm, p = 0.003, respectively). Furthermore, the presence of central necrosis and high maximal standardized uptake value (SUVmax) in FDG-PET-CT scans were significantly associated with LNM (60 vs. 11.5% of patients, p < 0.001 and median 8.59 vs. 3.96, p = 0.013, respectively). With systemic therapy, a slight median size regression over time was observed in both metastatic and benign LN. Serum LDH and CRP levels were significantly higher in patients with LNM (median 247 vs. 187.5U/L, p = 0.005 and 1.5 vs. 0.55 mg/dL, p = 0.039, respectively). This study shows significant associations between LNM and imaging features as well as laboratory parameters of STS patients. The largest SAD, SUVmax in FDG-PET-CT scan, the presence of central necrosis, and high serum LDH level are the most important parameters to distinguish benign from metastatic LNs.

Small gastric synovial sarcoma diagnosed and treatment by laparoscopic-endoscopic cooperative surgery: a case report

We report a case of small gastric synovial sarcoma (SS) finally diagnosed after laparoscopic-endoscopic cooperative surgery (LECS). A 50 year-old male underwent medical examination for a chief complaint of epigastric pain. Endoscopic examination showed a 20 mm submucosal tumor (SMT) located in the anterior wall which extended to the lesser curvature of the middle stomach. The biopsy tissue did not yield a definitive diagnosis. During 6 months of follow-up for this lesion suspected to be an inflammatory tumor, neither the shape nor the size of the tumor changed. We performed LECS for both diagnosis and treatment. Histologically, the tumor was composed of fascicles of spindle cells. Immunohistochemically, the tumor cells were focally positive for epithelial membrane antigen, cytokeratin (AE1/AE3) and S100 protein, while being negative for desmin, α-smooth muscle actin, CD34, c-kit and DOG1. The expression of INI1 was reduced. Fluorescence in situ hybridization (FISH) detected SS18 rearrangement. The SMT was diagnosed as primary SS. A SMT measuring < 20 mm might be malignant potential tumor such as SS even if there are no typical malignant findings by endoscopy. Surgical resection should be considered for SMT measuring < 20 mm with atypical findings even in the absence of definitive high-risk features.

Review on Lymph Node Metastases, Sentinel Lymph Node Biopsy, and Lymphadenectomy in Sarcoma

Soft tissue sarcomas (STS) originating from connective tissue rarely affect the lymph nodes. However, involvement of lymph nodes in STS is an important aspect of prognosis and treatment. Currently, there is no consensus on the diagnosis and management of lymph node metastases in STS. The key risk factor for nodal involvement is the histological subtype of sarcoma. Radiological and pathological evaluation seems to be the most effective method of assessing lymph nodes in these neoplasms. Thus, sentinel lymph node biopsy (SLNB), which has been shown to be valuable in the management of melanoma or breast cancer, may also be a beneficial diagnostic option in some high-risk STS subtypes. This review summarizes data on the risk factors and clinical characteristics of lymph node involvement in STS. Possible management and therapeutic options are also discussed.

Successful reconstruction using a buccal fat pad flap in misdiagnosed buccinators intramuscular synovial sarcoma: A case report

INTRODUCTION

Synovial sarcoma (SS) is a subtype of soft tissue sarcoma that primarily usually occurs in the lower extremities but rarely arises in the head and neck areas, including the oral cavity. Due to its variable presentation and similarity to benign masses in terms of age at onset, growth rate, and favorable outcomes, SS is often misdiagnosed as a benign tumor. However, it is a malignant tumor.

PATIENT CONCERNS

We report the case of intramuscular SS in the oral cavity. Initially, the lesion was clinically suspected as a benign mass but was ultimately confirmed as malignant SS.

DIAGNOSIS

Although histopathological examination is the first step in diagnosing SS, molecular testing to confirm the presence of SYT-SSX fusion can provide a definitive diagnosis when the histopathology is inconclusive. In this patient as well, the postoperative pathological report confirmed the diagnosis of biphasic SS, and molecular testing revealed positive SYT/SSX fusion.

THERAPEUTICS INTERVENTIONS

Following the recommendation of multidisciplinary care system, a wide excision was performed including the buccinators muscle, and reconstruction was performed using a buccal fat pad flap to prevent cheek depression.

OUTCOMES

On the final pathologic report, SS was removed margin-free, and there were no metastatic lymph nodes. No evidence of cheek dimpling was observed, and follow-up neck CT showed no significant changes in the lymph nodes. As a result of observation up to several months after surgery, there were no functional and aesthetic complications.

CONCLUSIONS

We report a successful case of intramuscular SS resection, initially misdiagnosed as a benign mass, using a buccal fat pad flap. We also highlight the importance of correctly diagnosing SS, especially in the craniofacial region where it can be mistaken for benign masses.

Local Therapies for Metastatic Sarcoma: Why, When, and How?

Management of patients with advanced sarcoma has been evolving in recent decades, from a one-fit-all perspective to a more refined, personalized, and multidisciplinary approach. In parallel, the evolution of local therapies (radiotherapy, surgical and interventional radiology techniques) has contributed to the improvement of survival of patients with advanced sarcoma. In this article, we review the evidence regarding local treatments in advanced sarcoma, as well as its integration with systemic therapies, to provide the reader a wider and deeper perspective on the management of patients with metastatic sarcoma.

Predicting five-year mortality in soft-tissue sarcoma patients

Aims

The aim of this study was to identify factors associated with five-year cancer-related mortality in patients with limb and trunk soft-tissue sarcoma (STS) and develop and validate machine learning algorithms in order to predict five-year cancer-related mortality in these patients.

Methods

Demographic, clinicopathological, and treatment variables of limb and trunk STS patients in the Surveillance, Epidemiology, and End Results Program (SEER) database from 2004 to 2017 were analyzed. Multivariable logistic regression was used to determine factors significantly associated with five-year cancer-related mortality. Various machine learning models were developed and compared using area under the curve (AUC), calibration, and decision curve analysis. The model that performed best on the SEER testing data was further assessed to determine the variables most important in its predictive capacity. This model was externally validated using our institutional dataset.

Results

A total of 13,646 patients with STS from the SEER database were included, of whom 35.9% experienced five-year cancer-related mortality. The random forest model performed the best overall and identified tumour size as the most important variable when predicting mortality in patients with STS, followed by M stage, histological subtype, age, and surgical excision. Each variable was significant in logistic regression. External validation yielded an AUC of 0.752.

Conclusion

This study identified clinically important variables associated with five-year cancer-related mortality in patients with limb and trunk STS, and developed a predictive model that demonstrated good accuracy and predictability. Orthopaedic oncologists may use these findings to further risk-stratify their patients and recommend an optimal course of treatment.

Presurgical Perspective and Posttreatment Evaluation of Soft Tissue Tumors of the Ankle and Foot in Adults

This article discusses soft tissue tumors of the ankle and foot region in adults, including tumors of the joints, and also briefly addresses tumor-simulating lesions. We offer general recommendations and describe specific aspects of common entities in that region, such as typical imaging appearance, therapeutic strategies, and posttherapeutic considerations. Focal masses and diffuse swelling are common in the foot and ankle region; most of them are non-neoplastic. Some of the tumors, such as plantar fibromatosis, tenosynovial giant cell tumor, synovial chondromatosis, or schwannoma, have a very typical appearance on magnetic resonance imaging. Sarcomas are rare among true soft tissue tumors; however, they can be small and well demarcated, may grow slowly, and are often misinterpreted as benign. This is especially true for synovial sarcoma, one of the most common sarcomas in this region. Densely packed tissues in the foot and ankle may hamper determining the tissue of origin. Adherence to diagnostic guidelines and cooperation with tumor centers is crucial including for posttherapeutic surveillance. We also describe typical posttherapeutic changes and complications after surgery, radiation therapy, and chemotherapy, as well as parameters for the detection and exclusion of recurrence of soft tissue tumors of the ankle and foot.

Pan-Soft Tissue Sarcoma Analysis of the Incidence, Survival, and Metastasis: A Population-Based Study Focusing on Distant Metastasis and Lymph Node Metastasis

Background

The rarity and complexity of soft tissue sarcoma (STS) make it a challenge to determine the incidence, survival, and metastasis rates. In addition, the clinicopathological risk factors for lymph node metastasis have rarely been reported.

Methods

Data on patients diagnosed with STS in the SEER database from 2000 to 2018 were extracted by SEER*Stat 8.3.9.1, and the incidence trend was calculated by Joinpoint 4.9 software. The KM method was used to calculate the survival curve, and the log-rank method was used to compare differences in the survival curves. The clinicopathological risk factors for lymph node metastasis were screened by logistic regression.

Results

Among the 35987 patients, 4299 patients (11.9%) had distant metastasis. The overall lymph node metastasis rate was 6.02%, which included patients suffering from both lymph node and distant metastasis. Considering that some lymph node metastases might be accompanying events of distant metastasis, the rate of only lymph node metastasis in STS patients decreased to 3.42% after excluding patients with distant metastasis. Patients with only lymph node metastases (N1/2M0) had a significantly worse prognosis than those without metastases (N0M0) but a better prognosis than those with only distant metastases (N0M1) (p<0.0001). In the multivariate logistic analysis, STS patients with larger tumors located in the head and neck, viscera, retroperitoneum, and certain specific pathological subtypes (compared with the liposarcoma), such as undifferentiated pleomorphic sarcoma, rhabdomyosarcoma, endometrial stromal sarcoma, gastrointestinal stromal tumor, synovial sarcoma, and angiosarcoma, had a higher risk of lymph node metastasis.

Conclusions

Lymph node metastasis is rare in STS, and the metastasis rate is significantly different among the different pathological types. Tumor size, location, and pathological subtype are significantly associated with the risk of lymph node metastasis. The overall survival of patients with lymph node metastasis is better than that of patients with distant metastasis, which suggests a more precise prognosis evaluation should be performed in these AJCC stage IV STS patients.

Synovial Sarcoma of the Foot as an Atypical Cause of Persistent Metatarsalgia: A Report of 3 Cases

CASE

Three cases of atypical metatarsalgia are presented, all diagnosed with foot synovial sarcomas (SSs) at different stages of evolution, after a year of medical consultations. One case was treated with marginal excision without requiring bone excision; the second patient required amputation of the first ray; and the third patient, with advanced disease, required amputation through Chopart's joint.

CONCLUSION

Metatarsalgia is a recurrent reason for consultation in orthopaedics. Even so, patients with persistent symptoms should be studied further in depth. Computed tomography or magnetic resonance imaging can detect tumor pathology, such as SS, of insidious development.

Trends of lymph node sampling and metastasis in pediatric and young adult patients with clear cell, epithelioid, and synovial sarcomas

BACKGROUND

Clear cell sarcoma of soft tissue (CCS), epithelioid sarcoma, and synovial sarcoma are rare tumors historically identified as high risk for lymph node metastasis. This study investigates incident nodal metastasis and associated survival in children and young adults with these subtypes.

PROCEDURE

Using the National Cancer Database (2004-2015), we created a retrospective cohort of 1303 patients (aged ≤25 years) who underwent local control therapy for CCS, epithelioid sarcoma, and synovial sarcoma. Kaplan-Meier curves estimated overall survival (OS) by subtype. Stratifying on subtype, Cox regressions assessed OS by lymph node sampling status and nodal metastasis.

RESULTS

There were 103 (7.9%) patients with CCS, 221 (17.0%) with epithelioid sarcoma, and 979 (75.1%) with synovial sarcoma. Lymph node sampling was more frequent in patients with CCS (56.3%) and epithelioid sarcoma (52.5%) versus synovial sarcoma (20.5%, p < .001). Synovial sarcoma metastasized to lymph nodes less frequently than CCS or epithelioid sarcoma (2.1% vs. 14.6% and 14.9%, p < .001). Across all subtypes, lymph node metastasis was associated with inferior OS (HR 2.02, CI 1.38-2.95, p < .001). Lymph node sampling was associated with improved OS in CCS (HR 0.35, CI: 0.15-0.78, p = .010), inferior OS in synovial sarcoma (HR 1.60, CI: 1.13-2.25, p = .007), and no statistical association with OS in epithelioid sarcoma.

CONCLUSIONS

Lymph node metastasis is rare in children and young adults with synovial sarcoma. Lymph node sampling procedures were not consistently performed for patients with CCS or epithelioid sarcoma, but improved OS supports routine lymph node sampling in children and young adults with CCS.

Epidemiological Trend Analysis and Survival Data of Balinese with Soft-Tissue Sarcoma in 2015–2021

BACKGROUND: Soft tissue sarcoma (STS) has a very heterogen features of its nature, subtypes, and clincial behaviour among population. Regardless, the epidemiology data of soft tissue sarcoma is very limited in developing countries, including Indonesia. AIM: To decribe the incidence and mortality trend analysis, as long as the survival data in Bali from 2015 to 2020. METHODS: This is a case control study including all subjects with STS in Denpasar, Bali, Indonesia from January 2015 to September 2021. Data about demographics, clinical, and survival timing data were collected from Cancer Registry. Soft tissue sarcoma diagnosis was confirmed after histopathological examination. Joinpoint regression was used for crude rate trend analysis. Data was analyzed by SPSS 22.0, using Kaplan-Meier for survival analysis. RESULTS: Ninety three subjects with STS were included in this study. Most patients died at the end of the study (65.6%) with median survival of only 30 months. The trend of STS age-standardized incidence and mortality rate was increasing from 2015 to 2018, then declining until 2020. The survival rate varies among the soft tissue sarcoma subtypes and location. It was better in the group without metastases, underwent therapy, but not statistically significant. CONCLUSION: Soft tissue sarcoma showed a diversity of demographic and clinical parameters. The incidence and mortality rate has plateued in 2018, but then declining. The survival rate diversed regarding of the STS subtype, location, metastasis, and treatment given.

Risk factors for lymph node metastasis of soft tissue sarcomas of the head, neck, and extremities, and the clinical significance of negative lymph node dissection

Background

This study sought to define the risk factors for lymph node metastasis (LNM) of soft tissue sarcomas (STS) of the head, neck, and extremities, and the clinical significance of negative lymph node dissection (NLND).

Methods

STS patient data in the Surveillance, Epidemiology, and End Results (SEER) database from 1988 to 2015 were extracted and pooled. Logistics regression analysis was used to identify risk factors for LNM, Cox proportional hazards and Fine–Grey’s models were used for survival analysis, and Propensity score matching analysis (PSM) was used to assess the impact of NLND on patient prognosis.

Results

A total of 3276 patients were enrolled in the study, of whom 283 (8.6%) developed LNM. Rhabdomyosarcoma had the highest rate of LNM (25.3%), followed by clear cell sarcoma (16.8%) and epithelioid sarcoma (12.4%), while leiomyosarcoma had the lowest rate of LNM (1.3%). Sex, tumor size, grade, histology, and site were significantly associated with LNM. For specific histologic subtypes of STS, NLND significantly improves overall survival (HR: 0.718, 95%CI 0.535–0.962; P = 0.026) and cancer-specific survival (HR: 0.699, 95%CI 0.506–0.967; P = 0.031) and reduces cancer-specific mortality (Gray’s test, P = 0.017). However, NLND did not improve overall survival (P = 0.46) or reduce cancer-specific mortality (Gray’s test, P = 0.772) of patients with leiomyosarcoma.

Conclusions

Histology is an independent risk factor for LNM in STS of the head, neck, and extremities. Prophylactic NLND treatment was necessary and had a clinical benefit for patients with STS who were at high risk for LNM but had no significant impact on the prognosis of patients with leiomyosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03050-3.

Biphasic synovial sarcoma with a striking morphological divergence from the main mass to lymph node metastasis: A case report

RATIONALE

Synovial sarcoma accounts for 5% to 10% of all soft tissue sarcomas and involves almost any anatomic site, particularly the deep soft tissue of the extremities of young adults. The incidence rate of lymph node metastases in synovial sarcoma is 3% to 7%, but the detailed morphological features of the metastatic tumors in the lymph node have not been documented.

PATIENT CONCERNS

A 64-year-old Korean man presented with a huge mass in the left lower thorax and multiple hypermetabolic lymph nodes along the mediastinal, supraclavicular, internal mammary, and retrocrural regions.

DIAGNOSES

The patient was diagnosed with primary pleuropulmonary biphasic synovial sarcoma with lymph node metastases, where the main mass mostly comprised spindle cells (>95%) and the metastatic lymph nodes comprised only epithelial cells.

INTERVENTIONS

Left lower lobe lobectomy with the resection of the chest wall (including left ribs 8-10) and diaphragm and mediastinal lymph node dissection were performed.

OUTCOMES

In the 2-month follow-up period, there have been no complications so far, and the attending physician is currently planning for the adjuvant chemotherapy.

LESSONS

The main mass and the metastatic lesion can be clearly different morphologically. In tumors with biphasic differentiation, such as synovial sarcoma, cells that constitute only a small fraction of the main mass may appear as the dominant cells in metastatic lesions.

Synovial sarcoma of the head and neck: A review of reported cases on the clinical characteristics and treatment methods

Synovial sarcoma (SS) is a high-grade soft-tissue sarcoma that occurs predominantly in older children and young adults in their thirties. It is usually very challenging to diagnose and treat synovial sarcoma in the head and neck region. The purpose of this review is to investigate the clinical manifestations and different treatment methods in the management of primary synovial sarcoma of the head and neck. HNSS has an aggressive nature and poor prognosis. Surgical resection, radiotherapy, and chemotherapy are the primary treatment methods. Typically, surgical resection with negative margins remains the foundation of therapy, which is not very easily achieved in the head and neck due to its complex anatomical structure and the presence of many blood vessels and nerves. However, synovial sarcoma has a high recurrence rate, so aggressive management and close follow-up are warranted for the optimal outcome.

Primary gastric synovial sarcoma resected by laparoscopic endoscopic cooperative surgery of the stomach: a case report

Background

Primary gastric synovial sarcoma is extremely rare, only 44 cases have been reported so far, and there have been no reports of laparoscopic endoscopic cooperative surgery for this condition.

Case presentation

A 45-year-old male patient presented with gastric pain. Esophagogastroduodenoscopy was performed that led to the identification of an 8-mm submucosal tumor in the anterior wall of the antrum, and a kit-negative gastrointestinal stromal tumor was suspected following biopsy. On endoscopic ultrasonography, the boundary of the tumor, mainly composed of the second layer, was depicted as a slightly unclear low-echo region, and a pointless no echo region was scattered inside. A boring biopsy revealed synovial sarcoma. Positron emission tomography did not reveal fluorodeoxyglucose (¹⁸F-FDG) accumulation in the stomach or other organs. Thus, the patient was diagnosed with a primary gastric synovial sarcoma, and laparoscopic endoscopic cooperative surgery was performed. The tumor of the antrum could not be confirmed laparoscopically from the serosa, and under intraoperative endoscopy, it had delle on the mucosal surface, which was removed by a method that does not involve releasing the gastric wall. Immunohistochemistry showed that the spindle cells were positive for EMA, BCL-2 protein, TLE-1, and SS18-SSX fusion-specific antibodies but negative for KIT and DOG-1. The final pathological diagnosis was synovial sarcoma of the stomach. The postoperative course was good, and the patient was discharged from the hospital on the 11th postoperative day.

Conclusion

Resection with laparoscopic endoscopic cooperative surgery (LECS), which has not been reported before, was effective for small synovial sarcomas that could not be confirmed laparoscopically. With the combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (CLEAN-NET) procedure, it was possible to excise the tumor with the minimum excision range of the gastric serosa without opening the stomach.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40792-021-01310-8.

Uncommon and peculiar soft tissue sarcomas: Multidisciplinary review and practical recommendations. Spanish Group for Sarcoma research (GEIS -GROUP). Part II

Among all Soft Tissue sarcomas there are some subtypes with low incidence and/or peculiar clinical behaviour, that need to be consider separately. Most of them are orphan diseases, whose biological characteristics imply a clearly different diagnostic and therapeutic approach from other more common sarcoma tumors. We present a brief and updated multidiciplinary review, focused on practical issues, aimed at helping clinicians in decision making. In this second part we review these subtypes: Alveolar Soft Part Sarcoma, Epithelioid Sarcoma, Clear Cell Sarcoma, Desmoplastic Small Round Cell Tumor, Rhabdoid Tumor, Phyllodes Tumor, Tenosynovial Giant Cell Tumors, Myoepithelial Tumor, Perivascular Epithelioid Cell Neoplasms (PEComas), Extraskeletal Myxoid Chondrosarcoma, NTRK-fusions Sarcomas. Most of them present their own radiological and histopathological feautures, that are essential to know in order to achieve early diagnosis. In some of them, molecular diagnosis is mandatory, not only in the diagnosis, but also to plan the treatment. On the other hand, and despite the low incidence, a great scientific research effort has been made to achieve new treatment opportunities for these patients even with approved indications. These include new treatments with targeted therapies and immunotherapy, which today represent possible therapeutic options. It is especially important to be attentive to new and potential avenues of research, and to promote the conduct of specific clinical trials for rare sarcomas.

Synovial Sarcoma: A Clinical Review

Synovial sarcomas (SS) represent a unique subset of soft tissue sarcomas (STS) and account for 5–10% of all STS. Synovial sarcoma differs from other STS by the relatively young age at diagnosis and clinical presentation. Synovial sarcomas have unique genomic characteristics and are driven by a pathognomonic t(X;18) chromosomal translocation and subsequent formation of the SS18:SSX fusion oncogenes. Similar to other STS, diagnosis can be obtained from a combination of history, physical examination, magnetic resonance imaging, biopsy and subsequent pathology, immunohistochemistry and molecular analysis. Increasing size, age and tumor grade have been demonstrated to be negative predictive factors for both local disease recurrence and metastasis. Wide surgical excision remains the standard of care for definitive treatment with adjuvant radiation utilized for larger and deeper lesions. There remains controversy surrounding the role of chemotherapy in the treatment of SS and there appears to be survival benefit in certain populations. As the understanding of the molecular and immunologic characteristics of SS evolve, several potential systematic therapies have been proposed.

Soft-tissue Sarcoma of the Hand: Patient Characteristics, Treatment, and Oncologic Outcomes

INTRODUCTION

The aim of this study was to describe patient characteristics, treatment, and oncologic outcomes of soft-tissue sarcomas (STSs) of the hand.

METHODS

Sixty-nine STSs of the hand in adult patients treated at a tertiary referral center were retrospectively included. We describe patient and tumor characteristics along with oncologic outcomes.

RESULTS

Epithelioid sarcoma (23%) was the most common histologic subtype, followed by synovial sarcoma (15%). Of all tumors, 17 (25%) were grade I, 22 (32%) were grade II, and 30 (44%) were grade III. The 5-year disease-free survival for epithelioid sarcomas was 75% with a disease survival of 100%, along with a metastatic rate of 15%. Of the patients with a synovial sarcoma, 40% developed metastases, and the 5-year disease-free survival was 68% and the 5-year disease survival was 73%.

CONCLUSION

Hand STSs are aggressive tumors with a high metastatic potential. Even with adequate oncologic treatment, long-term clinical follow-up (10 years) in these tumors is advised. The treating surgical oncologist should not be deceived by their smaller size.

Epidemiology, incidence, and survival of synovial sarcoma subtypes: SEER database analysis

BACKGROUND

Synovial sarcoma (SyS) is a rare malignancy that is typically located on the limbs and occurs predominantly in adolescents. A study in a large population for SyS comparing subtypes has not yet been reported.

METHODS

National Cancer Institute's Surveillance, Epidemiology, and End Results database was queried for patients diagnosed with SyS between January 1975 and December 2016. Patients were classified demographically according to gender, age, race/ethnicity, and marital status, and they were also classified by tumors, subtypes, localization, grade, year of diagnosis, laterality, type of treatment, and follow-up results.

RESULTS

A total of 3228 patients were included, with a mean age of 39.3 ± 18.8 (range: 1-94), of which 1521 (47.1%) were females and 1707 (52.9%) were males. According to its subtypes, 47.2% were SyS not otherwise specified, 32.3% were spindle cell, 19.9% were biphasic, and 0.6% were epithelioid type. The overall survival period is 138.0 (95% confidence interval: 113.2-162.8) months. Survival duration was found to be significantly different between groups according to gender (log-rank test; p < 0.001), age groups (log-rank test; p < 0.001), race (log-rank test; p = 0.001), marital status (log-rank test; p < 0.001), tumor subtypes (log-rank test; p < 0.001), tumor location (log-rank test; p < 0.001), tumor laterality (log-rank test; p < 0.001), date of diagnosis (log-rank test; p = 0.025), tumor grade (log-rank test; p < 0.001), historic stage (log-rank test; p < 0.001), state of chemotherapy (log-rank test; p < 0.001), state of radiotherapy (log-rank test; p < 0.001), presence of metastasis (log-rank test; p < 0.001), and total number of malignant tumors (log-rank test; p < 0.001).

CONCLUSION

Male gender, being colored individual, being over 35 years at the time of diagnosis, epithelioid type, non-head and neck region localization is associated with poor prognosis. While radiotherapy improves survival, benefit of chemotherapy is unclear.

LEVEL OF EVIDENCE

III retrospective analysis.

A Population-based Analysis of Lymph Node Metastasis in Extremity Soft Tissue Sarcoma: An Update

BACKGROUND

Soft tissue sarcomas (STSs) are mesenchymal tumors that may rarely metastasize to lymph nodes. This investigation sought to evaluate regional lymph node metastasis (RLNM) in extremity STS using a national cohort.

MATERIALS AND METHODS

This study was a retrospective review of the Surveillance, Epidemiology, and End Results database from 1975 to 2016. A Cox proportional hazards model was used to identify prognostic factors associated with disease-specific survival (DSS).

RESULTS

RLNM was present in 3.7% (n = 547) of extremity STS. The rate of RLNM was highest in rhabdomyosarcoma (26.7%), clear cell sarcoma (18.8%), epithelioid sarcoma (14.5%), angiosarcoma (8.1%), spindle cell sarcoma (5.0%), and synovial sarcoma (3.2%). The 5-year DSS probability without RLNM was 69% (standard error: 1.3%) compared to 26% (standard error: 3.6%) with RLNM (P < 0.001). For the historically high-risk extremity STS, advanced age (hazard ratio (HR), 1.036; 95% confidence interval (CI), 1.0-1.04; P < 0.001), higher grade tumors (HR, 1.979; 95% CI, 1.3-3.0; P < 0.001), tumor size greater than 10 cm (HR, 1.892; 95% CI, 1.3-2.7; P < 0.001), primary site surgery (HR, 0.529; 95% CI, 0.3-0.8; P = 0.006), distant metastasis (HR, 4.585; 95% CI, 3.0-6.8; P < 0.001), and RLNM (HR, 2.153; 95% CI, 1.3-3.5; P = 0.003) were each independent disease-specific prognostic factors.

CONCLUSIONS

The prognosis of RLNM in historically high-risk extremity STS is poor with a 5-year DSS of 26%. These data support a staging system of STS inclusive of nodal involvement and contribute to the growing body of evidence that characterizes the rates of RLNM in STS.

Lymphadenopathy in Fungating Extremity Soft-Tissue Sarcoma: Metastasis or Reactive?

BACKGROUND

Patients with fungating extremity soft-tissue sarcoma (STS) can develop lymphadenopathy, which can represent nodal metastasis or benign reactive adenopathy.

METHODS

In 1787 patients with STS, 67 (3.7%) had fungating extremity STS. In the 62 patients who met our inclusion criteria, we evaluated prevalence and histopathology of lymphadenopathy, factors associated with lymphadenopathy and nodal metastasis, and prevalence of and factors associated with lung metastasis and survival time from fungation. Logistic regression and Cox proportional-hazards models were used to analyze node pathology, lung metastasis, and survival duration with α = 0.05.

RESULTS

Lymphadenopathy occurred in 11 of 62 patients (18%), 6 with nodal metastasis and 5 with reactive adenopathy. The only factor associated with lymphadenopathy was location of primary tumor in the upper extremity (p = 0.02). No tumor characteristics were associated with nodal metastasis. In all five patients with reactive adenopathy, the condition was recognized within 3 days after tumor fungation. Lymphadenopathy recognized more than 3 days after tumor fungation was likely to be nodal metastasis. Forty-one percent of patients developed lung metastasis, which was not associated with presence of lymphadenopathy or any patient or tumor characteristic. Age, tumor size, and Black and Asian race were independently associated with greater risk of death.

CONCLUSIONS

Eighteen percent of patients with fungating extremity STS developed lymphadenopathy. Approximately half of cases represented nodal metastasis, and half represented reactive adenopathy. Lymphadenopathy that develops within 3 days after tumor fungation should increase suspicion for reactive adenopathy versus nodal metastasis.

Should metastatic lymph nodes be considered at the same clinical stage as distant metastasis in soft tissue sarcomas?

INTRODUCTION

Lymph node metastasis (LNM) in soft tissue sarcomas (STS) are uncommon, occurring in only 3% - 5% of all sarcomas, and are classified as Stage IV, along with distant metastasis (DM). This paper compares the prognosis of patients with lymphatic and DM, in extremity STS (eSTS).

METHODS

A retrospective study was carried out in a high-volume sarcoma center; 853 patients with eSTS sarcomas were identified and classified from January 1, 1997 to December 31, 2017. Cases with pathological confirmation of LNM were included. Five-year survival rates were analyzed using the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS

LNM was present in 46 of the cases (5.4%), with an overall survival of 21 months (95% confidence interval [CI], 16.7 - 25.2), compared to 18 months (95% confidence interval [CI], 14.2 - 21.7) in those with only DM. Median recurrence-free survival was 21 months (95% confidence interval [CI], 19.7 - 22.4), vs. 20 months (95% confidence interval [CI], 16.2- 23.7), respectively. LNM only and DM only had also a similar OS of 21 months (95% CI 16.7-25.2) vs 18 months (95% CI 14.2-21.7. N1M1 cases had the worse median OS with 15 months (95% confidence interval [CI], 10.9-19.7) CONCLUSIONS: Overall survival and recurrence free survival in patients with lymph node disease and metastatic disease are similar. However prognosis is worse in N1M1. Use of systemic treatment in patients with LNM is not as common as in metastatic cases, this difference in treatment and the fact that prognosis is similar suggests that both biological behavior and effect of treatment have been underestimated. A subclassification of clinical stage IV might be the next step.

The survival and prognosis analysis of synovial sarcoma subtypes: a Surveillance, Epidemiology, and End Results population-based analysis

PURPOSE

By comparing epidemiologic and prognostic data of synovial sarcoma subtypes, this study aims to clarify the difference in prognosis and risk factors among different synovial sarcoma subtypes.

METHODS

In total, 1692 patients with synovial sarcoma in the USA who were diagnosed during 1975 through 2016 and retrieved from the Surveillance, Epidemiology, and End Results (SEER) program were studied.

RESULTS

There were statistically significant differences in the distribution of age and race among three synovial sarcoma subtypes, while no major differences in the distribution of sex, tumor stage, and tumour size were found. The highest five and ten year survival rates were found in the biphasic subtype (69%, 60%), followed by the monophasic subtype (59%, 49%), and lowest in the epithelioid subtype (32%, 26%). Age and SEER historic stage were the two demographic factors that found to have statistically significant impact on survival in all subtypes. Radiation was found to be protective in the monophasic subtype (HR 0.61, p < 0.001).

CONCLUSION

Among different synovial sarcoma subtypes, the biphasic subtype favoured the best survival, while the epithelioid cell subtype was associated with the worst. Male and black race were independently associated with worse survival only in the monophasic subtype. Radiotherapy could provide significant benefit for patients with the monophasic synovial sarcoma.

Extraskeletal myxoid chondrosarcoma: A high incidence of metastatic disease to lymph nodes

BACKGROUND

Extraskeletal myxoid chondrosarcoma (ESMC) is a rare type of soft-tissue sarcoma with limited series reporting outcome of treatment. Currently there is limited data on the incidence and impact on patient outcome in those with metastatic disease to lymph nodes in ESMC.

METHODS

Thirty (21 males, 9 females) patients, mean age 50 ± 16 years, with ESMC were reviewed. The tumors were most commonly located in the lower extremity (n = 23, 77%) and the mean tumor size and volume were 9 ± 5 cm and 490 ± 833 cm³ . Mean follow up was 7 ± 4 years.

RESULTS

Six (20%) patients either presented (n = 3, 10%) or developed (n = 3, 10%) lymph node metastatic disease. When comparing patients without, with lymph node metastasis and metastasis elsewhere, patients with lymph nodes metastasis had worse survival than those without metastasis, however better 10-year disease specific survival than those with metastasis elsewhere (100% vs 62% vs 0%; P < .001).

CONCLUSION

There is a high incidence of lymph node metastatic disease in patients with ESMC. Although survival in these patients is worse compared to those without metastasis, their survival is better than those with metastasis elsewhere. Due to the high incidence of lymph node metastatic disease, preoperative staging of the lymph node should be considered.

Treatment of limb synovial sarcoma with metastasis at presentation

Limb synovial sarcoma (LSS) patients with metastasis at presentation usually have a very poor prognosis. Little is known about survival prediction and risk factors in these patients owing to the condition's rarity. Thus, this study examined the survival and prognostic variables of metastatic LSS.Clinical data for LSS patients with metastasis at presentation from 1975 to 2016 were obtained from the surveillance, epidemiology, and end results database. The Kaplan-Meier method was used to determine the survival curves. Univariate and multivariate Cox regression analysis were conducted to identify the prognostic predictors.The study enrolled 217 patients. Male predominance was observed in the metastatic LSS group. The median age at diagnosis of this population was 40 years. The subtypes were "not otherwise specified" (49.8%), spindle cell (32.7%), biphasic (17.1%), and epithelioid cell (0.5%). The 3-year overall and cancer-specific survival rates of the entire group were 27.2% and 28.3%, respectively. Tumor size <10 cm, surgery, radiotherapy, and chemotherapy were independent predictors of improved overall and cancer-specific survival in the multivariate analyses.Comprehensive treatment for LSS patients with metastasis at diagnosis is necessary and effective and can prolong survival.

Sarcoma metastasis to the pancreas: experience at a single institution

Background

Reports of metastatic sarcoma to the pancreas are limited. We reviewed the clinicopathologic characteristics of such cases.

Methods

We reviewed 124 cases of metastatic tumors to the pancreas diagnosed at Asan Medical Center between 2000 and 2017.

Results

Metastatic tumors to the pancreas consisted of 111 carcinomas (89.5%), 12 sarcomas (9.6%), and one melanoma (0.8%). Primary sarcoma sites were bone (n=4); brain, lung, and soft tissue (n=2 for each); and the uterus and pulmonary vein (n=1 for each). Pathologically, the 12 sarcomas comprised 2 World Health Organization grade III solitary fibrous tumors/hemangiopericytomas, and one case each of synovial sarcoma, malignant solitary fibrous tumor, undifferentiated pleomorphic sarcoma, osteosarcoma, mesenchymal chondrosarcoma, intimal sarcoma, myxofibrosarcoma, myxoid liposarcoma, rhabdomyosarcoma, subtype uncertain, and high-grade spindle-cell sarcoma of uncertain type. The median interval between primary cancer diagnosis and pancreatic metastasis was 28.5 months. One case manifested as a solitary pancreatic osteosarcoma metastasis 15 months prior to detection of osteosarcoma in the femur and was initially misdiagnosed as sarcomatoid carcinoma of the pancreas.

Conclusions

The metastatic sarcoma should remain a differential diagnosis when spindle-cell malignancy is found in the pancreas, even for solitary lesions or in patients without prior history.

Nodal metastases of soft tissue sarcomas: risk factors, imaging findings, and implications

Soft tissue sarcomas (STS) are malignancies derived from connective tissue, and regional lymph node metastasis (RLNM), while not common, is an important aspect of prognosis and treatment. Various risk factors, in particular the histological subtype, affect the likelihood of nodal involvement, which can be characterized by imaging features such as nodal dimension and morphology. Currently, surveillance and management vary by institution, as concrete societal guidelines have not been established. Common nodal status assessment strategies include physical exam, US CT, MRI, sentinel lymph node biopsy (SLNB) and radical lymphadenectomy. This article summarizes data regarding relevant risk factors of RLNM, imaging features, and any available data regarding surveillance recommendations.

Innovative analysis of distant metastasis in differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most common thyroid cancer with a relatively high survival rate. The association between certain risk factors of distant metastasis (DM) remains uncertain. In order to assess the prognosis of patients with DTC better, the present study aimed to investigate the synergistic effects between histologic subtype, tumor size, lymph node metastasis (LNM) status and extrathyroidal extension (ETE) on the incidence of DM in DTC. Data of 96,788 patients with DTC were obtained from the Surveillance, Epidemiology and End Results database. The association between clinicopathological factors and DM was evaluated by univariate and multivariate analyses. The synergistic effects of relevant factors were determined by measuring the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (SI). The results demonstrated that tumor size, LNM status, histologic subtype and ETE were independent risk factors for DM [odds ratio (OR)=2.433; P<0.001; OR=3.998; P<0.001; OR=6.266; P<0.001; and OR=3.873; P<0.001, respectively]. In addition, a significant additive synergistic effect on DM was identified between ETE and histologic subtype, ETE and LNM status, as well as between ETE and tumor size (RERI=34.097; AP=0.706; SI=3.585; RERI=6.425; AP=0.410; SI=1.781; and RERI=76.973; AP=0.864; SI=7.930, respectively). Therefore, the results of this study revealed that ETE with follicular thyroid histology, N1 stage or large tumor size may have a synergistic effect on the risk of DM in patients with DTC. These results suggested that individualized treatment may benefit patients with DTC, and when ETE coexists with one of the identified risk factors, radical treatments may be required.

Clinical and strategic outcomes of metastatic synovial sarcoma on limb

OBJECTIVE

Synovial sarcoma (SS) is one of the most frequent malignant soft-tissue tumors, and nearly 65% arise in the lower extremities. Survival prediction and the risk factors of the patients are poorly understood. Thus, this study examined the survival and prognostic variables of metastatic limb SS (LSS).

METHODS

Clinical data of LSS patients with metastasis at the presentation from 1975 to 2017 were obtained from the Surveillance, Epidemiology, and End Results database program database. Kaplan-Meier method was used to describe the survival curves. Univariate and multivariate Cox regression analysis were conducted to reveal the real prognostic predictors.

RESULTS

Male predominance was observed in the metastatic LSS group from a total number of 217 patients. This population was composed of 49.8% not other specified subtype, 32.7% spindle cell subtype, 17.1% biphasic subtype, and 0.5% epithelioid cell subtype. The 3-year overall survival (OS) and cancer-specific survival (CSS) rates of the entire group were 27.2% and 28.3%, respectively. Tumor size <10 cm, surgery, radiotherapy, and chemotherapy were calculated as independent predictors of improved OS and CSS by multivariate analyses.

CONCLUSION

SS is still a disease with a poor prognosis. This can increase the survival rate and time by the well-planned treatment.

Predictors of Lymph Node Involvement by Soft Tissue Sarcoma of the Trunk and Extremity: An Analysis of the National Cancer Database

Background and Objectives

Lymph node metastases (LNM) in soft tissue sarcoma (STS) of the trunk and extremity are rare but are associated with worse survival. Established risk factors for LNM in this group are based on small institutional retrospective reviews. This study identifies the risk factors associated with LNM in otherwise non-metastatic trunk/extremity STS patients using the National Cancer Database (NCDB) and sought out to delineate a high-risk group that may be considered for pathologic nodal evaluation.

Methods

The files of 10,731 patients with STS of the trunk/extremity without distant metastasis from 2004 - 2015 were evaluated. Exclusion criteria included neoadjuvant therapy and a lack of pathologic nodal evaluation. Univariate and multivariable logistic regression models were performed to evaluate variables associated with LNM.

Results

Of the total of 10,731 patients, 223 (2.1%) had LNM. On multivariable analysis, LNM was associated with Grade 3 tumors (odds ratio (OR) 15.6, 95% confidence interval (CI) 6.36 - 38.04, p < 0.001) and clear cell/angiosarcoma/rhabdomyosarcoma/epithelioid (CARE) histology (OR 4.72, 95% CI 3.35 - 6.66, p < 0.001), lymphovascular invasion (LVI) (OR 5.86, 95% CI 3.33 - 10.31, p < 0.001, and bone invasion (BI) (OR 2.73, 95% CI 1.32 - 5.61, p = 0.006). Patients with Grade 3 CARE tumors (n = 402) had an 11.9% risk of LNM vs. 1.7% of adults without all these characteristics (p < 0.001). Patients with Grade 3 CARE tumors and either LVI or BI (n = 36) had a 33.3% risk of LNM.

Conclusions

High-grade and CARE histology are associated with LNM in STS. Adult patients with both features have an overall 11.9% risk of LNM and may be considered for pathologic LN assessment, particularly with the presence of LVI or BI.