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Recently, DNA methylation clocks have been proven to be precise age predictors, and the application of these clocks in cancer tissue has revealed a global age acceleration in a majority of cancer subtypes when compared to normal tissue from the same individual. The polycomb repressor complex 2 plays a pivotal role in the aging process, and its targets have been shown to be enriched in CpG sites that gain methylation with age. This complex is further regulated by the chromatin remodeling complex SWItch/Sucrose Non-Fermentable and its core subunit, notably the tumor suppressor gene SMARCB1, which under physiological conditions inhibits the activity of the polycomb repressor complex 2. Hence, the loss of function of core members of the SWItch/sucrose non-fermentable complex, such as the tumor suppressor gene SMARCB1, results in increased activity of polycomb repressor complex 2 and interferes with the aging process. SMARCB1-deficient neoplasms represent a family of rare tumors, including amongst others malignant rhabdoid tumors, atypical teratoid and rhabdoid tumors, and epithelioid sarcomas. As aging pathways have recently been proposed as therapeutic targets for various cancer types, these tumors represent candidates for testing such treatments. Here, by deriving epigenetic age scores from more than 1000 tumor samples, we identified epigenetic age acceleration as a hallmark feature of epithelioid sarcoma. This observation highlights the potential of targeting aging pathways as an innovative treatment approach for patients with epithelioid sarcoma. [ABSTRACT FROM AUTHOR]

Epithelioid sarcoma (ES) is a rare soft tissue tumor that is commonly misdiagnosed. It is a mesenchymal tumor that shows both mesenchymal and epithelial features. It tends to occur in the distal upper extremity in children and young adults but may appear in any location and any age group. Less than 1% of ES involve the head and neck. Clinically, the tumor can be mistakenly confused with a benign lesion as it can mimic nonspecific ulcers or infected warts. Histologically, ES is characterized by a nodular architecture and epithelioid appearance of cells centered with necrosis, mimicking a granulomatous process. We present the clinical history of a 12-year-old male who presented with an ES of the pretragus with a brief review of the literature to raise awareness on this rare entity and to discuss the challenges in managing histopathological differential diagnosis in front of this unusual clinical presentation. [ABSTRACT FROM AUTHOR]

Epithelioid sarcoma (ES) is a rare soft tissue neoplasm with high recurrence rates. Wide surgical resection remains the only potential curative treatment. ES presents most commonly on the fingers, hands and forearm, making light-based cancer cell-targeted therapies such as near-infrared photoimmunotherapy (NIR-PIT) that is target-specific, but with limited penetration depth, suitable for ES treatment. We established that CD44 and EGFR were overexpressed in ES patient samples and in the VA-ES-BJ human ES cell line. NIR-PIT of VA-ES-BJ cells using antibody photosensitizer conjugates, prepared by conjugating a CD44 or EGFR monoclonal antibody to the photosensitizer IR700, confirmed that NIR-PIT with both conjugates resulted in cell death. Neither treatment with NIR light alone nor treatment with the conjugates but without NIR light were effective. CD44-IR700-PIT resulted in greater cell death than EGFR-IR700-PIT, consistent with the increased expression of CD44 by VA-ES-BJ cells. In tumors, EGFR-IR700 exhibited a higher tumor-to-normal ratio, as determined by in vivo fluorescence imaging, and a higher anti-tumor growth effect, compared to CD44-IR700. No antitumor effect of the EGFR antibody or the photosensitizer conjugate alone was observed in vivo. Our data support evaluating the use of EGFR-IR700-PIT in the management of ES for detecting and eliminating ES cells in surgical margins, and in the treatment of superficial recurrent tumors.

Abstract Background Epithelioid sarcoma is a rare soft tissue sarcoma characterized by SMARCB1/INI1 deficiency. Much attention has been paid to the selective EZH2 inhibitor tazemetostat, where other systemic treatments are generally ignored. To explore alternative treatment options, we studied the effects of irinotecan-based chemotherapy in a series of epithelioid sarcoma patients. Methods We retrospectively reviewed data from patients with metastatic or unresectable epithelioid sarcoma at the Peking University People’s Hospital treated with irinotecan (50 mg/m2/d d1-5 Q3W) in combination with Anlotinib (12 mg Qd, 2 weeks on and 1 week off) from July 2015 to November 2021. Results A total of 54 courses were administered. With a median follow up of 21.2 months (95% CI, 12.2, 68.1), the 5-year overall survival rate was 83.3%. Five of eight (62.5%) patients presented with unresectable localized lesions, including local tumor thrombosis and lymphatic metastasis. The other patients had unresectable pulmonary metastases. Six of eight (75%) patients had progressed following two lines of systemic therapy. The objective response rate reached 37.5% (three of eight patients) while stabilized disease was observed in 62.5% (five of eight) of patients. No patient had progressed at initial evaluation. At the last follow up, two patients were still using the combination and three patients had ceased the therapy due to toxicities such as diarrhea, nausea, and emesis. One patient changed to tazemetostat for maintenance and one patient stopped treatment due to coronavirus disease 2019 (COVID-19). Another patient stopped therapy as residual lesions had been radiated. Conclusions The combination of irinotecan and Anlotinib as a salvage regimen may be considered another effective treatment option for refractory epithelioid sarcoma. Trial registration This study was approved in the Medical Ethics Committee of Peking University People’s Hospital on October 28, 2022 (No.: 2022PHD015-002). The study was registered in Clinicaltrials.gov with identifier no. NCT05656222.

Background: Epithelioid sarcoma is a rare soft tissue sarcoma characterized by SMARCB1/INI1 deficiency. Much attention has been paid to the selective EZH2 inhibitor tazemetostat, where other systemic treatments are generally ignored. To explore alternative treatment options, we studied the effects of irinotecan-based chemotherapy in a series of epithelioid sarcoma patients. Methods: We retrospectively reviewed data from patients with metastatic or unresectable epithelioid sarcoma at the Peking University People's Hospital treated with irinotecan (50 mg/m2/d d1-5 Q3W) in combination with Anlotinib (12 mg Qd, 2 weeks on and 1 week off) from July 2015 to November 2021. Results: A total of 54 courses were administered. With a median follow up of 21.2 months (95% CI, 12.2, 68.1), the 5-year overall survival rate was 83.3%. Five of eight (62.5%) patients presented with unresectable localized lesions, including local tumor thrombosis and lymphatic metastasis. The other patients had unresectable pulmonary metastases. Six of eight (75%) patients had progressed following two lines of systemic therapy. The objective response rate reached 37.5% (three of eight patients) while stabilized disease was observed in 62.5% (five of eight) of patients. No patient had progressed at initial evaluation. At the last follow up, two patients were still using the combination and three patients had ceased the therapy due to toxicities such as diarrhea, nausea, and emesis. One patient changed to tazemetostat for maintenance and one patient stopped treatment due to coronavirus disease 2019 (COVID-19). Another patient stopped therapy as residual lesions had been radiated. Conclusions: The combination of irinotecan and Anlotinib as a salvage regimen may be considered another effective treatment option for refractory epithelioid sarcoma. Trial registration: This study was approved in the Medical Ethics Committee of Peking University People's Hospital on October 28, 2022 (No.: 2022PHD015-002). The study was registered in Clinicaltrials.gov with identifier no. NCT05656222. [ABSTRACT FROM AUTHOR]

Background: Patients with neurofibromatosis type I (NF1) have an increased risk of developing soft-tissue sarcomas, particularly those related to the nervous system. Epithelioid sarcoma (ES) is an exceptionally rare subtype of soft-tissue sarcoma, with limited knowledge about its clinical presentation and optimal management in NF1. This report aims to provide insights into the characteristics and outcomes of ES in NF1 patients. Case description: A 37-year-old man with a history of NF1 presented with a progressively worsening mass on his right inner thigh. An MRI scan revealed a well-defined tissue mass originating from the adductor magnus muscle, later confirmed as ES through histopathology and immunohistochemistry. Considering poor local and general prognosis, the multidisciplinary team recommended salvage hip disarticulation, however the patient refused and opted for palliative marginal resection to reduce the tumour size. The patient’s condition declined rapidly, and he succumbed six days after the surgery. Conclusion: This case highlights the rarity of ES in NF1 patients and underscores the potential for malignant tumour development in this population. Further research is needed to improve our understanding and management of sarcomas in the context of NF1.

Epithelioid sarcoma is a rare aggressive soft tissue sarcoma, which can be distal or proximal types. The classic form (distal-type) of epithelioid sarcoma mainly occurs in teenagers and young adults. A rarer form, called large-cell (proximal-type) epithelioid sarcoma, tends to be more aggressive and mainly affects adults. The proximal subtype mostly arises from the proximal pelvis, limbs, and genital tract. We report a case of a 59 -year-old female, presented with a progressively growing mass in the left labia majora. Gynecologic examination revealed a 2 cm mobile and painless mass that was not attached to deep planes. The histological study showed a multinodular tumor was seen comprising sheets of oval to polygonal cells with moderate amount of cytoplasm. Interspersed were larger, rhabdoid cells with abundant eosinophilic cytoplasm and prominent nucleoli. On IHC, the tumor cells showed positivity for EMA and CKAE1/AE3 and do not expressed INI-1 in the nucleus. All tumor cells were negative for S-100 protein and CD34. The histopathological diagnosis was soft tissue of the vulvar region with proximal epithelioid sarcoma. The patient received adjuvant external pelvic radiotherapy and brachytherapy in the vulvar bed. Currently, 3 years after diagnosis, the patient does not present signs of tumor recurrence in her controls. Due to its low incidence, there are no evidence-based diagnostic algorithms or published recommendations for treatment. The prognosis is generally poor. A wide excision with clear margins is imperative with options of post-operative CT/RT in individual cases during a close follow-upbehavior, as seen in our case.

Abstract Background Epithelioid sarcoma (ES) is a rare form of mesenchymal malignancy that rarely occurs in children. Only seven cases of intra-articular epithelioid sarcoma have been reported in the medical literature. Case presentation In this report, we presented the case of a 13-year-old girl with a delayed diagnosis of ES in the left knee. Her initial diagnosis was mistaken for Pigmented Villonodular Synovitis (PVNS) but ruled out later by the first biopsy. However, the lesion rapidly regrew again after arthroscopy, raising suspicions of malignancy. A comprehensive histochemistry examination was conducted again, leading to the diagnosis of INI-1 negative epithelioid sarcoma. Unfortunately, the girl passed away seven months later due to early metastasis of the tumor. Conclusion Careful consideration should be given to the differential diagnosis of pediatric patients presenting with monoarthritis. This report highlights the importance of early and accurate diagnosis and underscores the necessity for effective treatments for epithelioid sarcoma. Surgical resection or radical surgery is recommended, while novel treatment strategies targeting EZH2 show promise.

Background: Epithelioid sarcoma (ES) is a rare form of mesenchymal malignancy that rarely occurs in children. Only seven cases of intra-articular epithelioid sarcoma have been reported in the medical literature. Case presentation: In this report, we presented the case of a 13-year-old girl with a delayed diagnosis of ES in the left knee. Her initial diagnosis was mistaken for Pigmented Villonodular Synovitis (PVNS) but ruled out later by the first biopsy. However, the lesion rapidly regrew again after arthroscopy, raising suspicions of malignancy. A comprehensive histochemistry examination was conducted again, leading to the diagnosis of INI-1 negative epithelioid sarcoma. Unfortunately, the girl passed away seven months later due to early metastasis of the tumor. Conclusion: Careful consideration should be given to the differential diagnosis of pediatric patients presenting with monoarthritis. This report highlights the importance of early and accurate diagnosis and underscores the necessity for effective treatments for epithelioid sarcoma. Surgical resection or radical surgery is recommended, while novel treatment strategies targeting EZH2 show promise. [ABSTRACT FROM AUTHOR]

BACKGROUND: Epithelioid fibrous histiocytoma is a rare morphologic variant of benign fibrous histiocytoma. Most commonly it presents in the lower limbs of young adults as a well-defined nodular lesion. Microscopically due to its epithelioid-like morphology, it has multiple differential diagnosis. CLINICAL CASE: A 43-year-old male presented an ovoid, exophytic lesion in the knee, clinically compatible with dermatofibroma. Surgical resection was performed without recurrences to date. Histopathologic findings showed distinctive hallmarks such as well-formed epidermal collarette and pleomorphic appearance cells. CONCLUSIONS: It is important to recognize histopathologically this variant of benign fibrous histiocytoma and differentiate it from neoplastic processes with similar epithelioid morphology, both benign such as Spitz nevus and malignant like amelanotic melanoma and epithelioid sarcoma. [ABSTRACT FROM AUTHOR]

Abstract Objective The prognostic factors for patients with epithelial sarcoma remain unclear. The study aims to develop a practical clinical nomogram that predicts prognosis in patients with ES using the Surveillance, Epidemiology, and End Results (SEER) database. Methods We extracted clinical data from 2004 to 2015 from the SEER database about patients with ES. All patients were randomly divided into training cohort and validation cohort. Kaplan–Meier analyses were used to compare outcomes between different subgroups. In order to estimate the chance of survival for patients with ES, we developed a nomogram. Nomogram performance was evaluated by discrimination and calibration. Additionally, an analysis of decision curves was conducted to evaluate the clinical usefulness of this newly developed model. Results In the primary cohort,320 met the inclusion criteria to be entered into this study. The median OS was 66.000 months (range 34.704 to 94.296 months), and the 1‐, 3‐, and 5‐year OS rates were 70.7%, 56.1%, and 50.4%, respectively. For the validation cohort, we studied 136 consecutive patients. Age, primary site, grade, AJCC (American Joint Committee on Cancer) T, AJCC M, and surgery were included in the nomogram. The C‐index values for the training set and validation set were 0.817 and 0.832, respectively. The calibration plots showed good agreement between the prediction and the observation. Based on the clinical decision curve, the model has a good clinical net benefit for ES patients. Conclusions It is the first study that developed an effective survival prediction model for patients with ES. Using this nomogram can assist in clinical decision‐making as it has satisfactory accuracy. Even so, additional external validation is needed.

Background: Diverse lesions ranging from infective, inflammatory to neoplastic can occur in the hand. Almost all lesions that occur elsewhere in the body can affect the hand as well. Methods: This was a hospital-based retrospective study of 5 years done between January 2016 and December 2020. We enumerated the clinical and histopathological spectrum of lesions of the hand. The details were collected from the patient requisition forms and pathology records. Results: Of the 80 cases seen during the study period, 25 (31.3%) were non-neoplastic and 55 (68.8%) were neoplastic; male: female ratio was 0.95:1. The most frequent lesions identified were ganglion cysts (n = 13), followed by giant cell tumour (GCT) of tendon sheath (n = 11). Common non-neoplastic lesions included were ganglion cyst (n = 13), pyogenic granuloma (n = 3); epidermoid cyst, fungal granuloma, pigmented seborrhoeic keratosis (n = 2 each) and cutaneous horn, molluscum contagiosum and granulomatous inflammation. Amongst neoplastic lesions, mesenchymal lesions were 49 (89.1%) and epithelial lesions were 6 (10.9%); they were GCT of tendon sheath 11 (22.4%) lipomas and nerve sheath tumours 9 (18.36%) cases each, arteriovenous malformations/haemangiomas 5 (10.2%), fibromas 2 (4.08%) and one (2.04%) case each of myolipoma, fibrolipoma, benign fibrous histiocytoma, calcifying aponeurotic fibroma and benign spindle cell tumour, palmar fibromatosis. Malignant mesenchymal neoplasms included synovial sarcoma (n = 3), epithelioid sarcoma, malignant peripheral nerve sheath tumour and high-grade spindle cell sarcoma (n = 1 each). Amongst epithelial, benign lesions were 2, malignant lesions were 4, of which 3 were squamous cell carcinoma and one was melanoma and the two benign lesions were skin adnexal tumours, of which one was a case of eccrine poroma and the other was pilomatrixoma. Conclusions: In patients presenting with lumps and bumps on the hand, common non-neoplastic lesions included ganglion cyst and pyogenic granuloma. Amongst neoplastic lesions, mesenchymal lesions and epithelial lesions were most commonly seen.

Epithelioid sarcoma (ES) is a very rare sarcoma characterized by loss of INI1. Enzinger first described ES in 1970, but the histopathologic differential diagnosis of ES remains challenging. There are two ES subtypes, the classical type with spindle epithelioid to the central pseudogranulomatous cells, and the proximal type, which is predominantly composed of epithelioid and rhabdoid cells. ES symptoms and signs are not specific and depend on tumor localization. The only treatment for ES is radical excision with a microscope-radical margin. In general, the best treatment for ES in extremes is radical resection with a wide margin or amputation with or without lymph node dissection. Surgery may be followed by adjuvant chemotherapy and/or radiation therapy. Referral of patients with ES to a sarcoma center that offers hypofractionation RT trials and multidisciplinary clinical trials should be considered upfront. Neoadjuvant chemotherapy with ifosfamide and doxorubicin with / or without radiation therapy must be used after a multidisciplinary team discussion. On 23 January 2020, the US Food and Drug Administration (FDA) first approved tazemetostat – an inhibitor of zeste homolog 2 enhancer – therapy for metastatic ES or locally advanced ES not eligible for radical resection. [ABSTRACT FROM AUTHOR]

Background: Diverse lesions ranging from infective, inflammatory to neoplastic can occur in the hand. Almost all lesions that occur elsewhere in the body can affect the hand as well. Methods: This was a hospital-based retrospective study of 5 years done between January 2016 and December 2020. We enumerated the clinical and histopathological spectrum of lesions of the hand. The details were collected from the patient requisition forms and pathology records. Results: Of the 80 cases seen during the study period, 25 (31.3%) were non-neoplastic and 55 (68.8%) were neoplastic; male: female ratio was 0.95:1. The most frequent lesions identified were ganglion cysts (n = 13), followed by giant cell tumour (GCT) of tendon sheath (n = 11). Common non-neoplastic lesions included were ganglion cyst (n = 13), pyogenic granuloma (n = 3); epidermoid cyst, fungal granuloma, pigmented seborrhoeic keratosis (n = 2 each) and cutaneous horn, molluscum contagiosum and granulomatous inflammation. Amongst neoplastic lesions, mesenchymal lesions were 49 (89.1%) and epithelial lesions were 6 (10.9%); they were GCT of tendon sheath 11 (22.4%) lipomas and nerve sheath tumours 9 (18.36%) cases each, arteriovenous malformations/haemangiomas 5 (10.2%), fibromas 2 (4.08%) and one (2.04%) case each of myolipoma, fibrolipoma, benign fibrous histiocytoma, calcifying aponeurotic fibroma and benign spindle cell tumour, palmar fibromatosis. Malignant mesenchymal neoplasms included synovial sarcoma (n = 3), epithelioid sarcoma, malignant peripheral nerve sheath tumour and high-grade spindle cell sarcoma (n = 1 each). Amongst epithelial, benign lesions were 2, malignant lesions were 4, of which 3 were squamous cell carcinoma and one was melanoma and the two benign lesions were skin adnexal tumours, of which one was a case of eccrine poroma and the other was pilomatrixoma. Conclusions: In patients presenting with lumps and bumps on the hand, common non-neoplastic lesions included ganglion cyst and pyogenic granuloma. Amongst neoplastic lesions, mesenchymal lesions and epithelial lesions were most commonly seen. [ABSTRACT FROM AUTHOR]

Proximal-type epithelioid sarcoma of the perineum is a rare soft-tissue malignancy, and only 55 cases have been reported in the English literature to date. This tumor has an indetectable early symptom and frequent recurrences. Here, we present the case of a 31-year-old man with proximal-type epithelioid sarcoma of the perineum who underwent wide excision. Further, we reviewed the current literature regarding differential diagnosis and management of this disease. [ABSTRACT FROM AUTHOR]

Primary soft-tissue sarcomas of the paratesticular region are uncommon tumors comprising 1% of all adult sarcomas. Paratesticular epithelioid sarcoma (ES) is a rare subtype. Here, we report the case of a 68-years-old male with scrotal swelling who underwent high inguinal exploration and right orchidectomy. Histopathology and immunohistochemistry revealed paratesticular ES. Very few cases of paratesticular ES have been reported so far in the literature. Clinical presentation, investigations, treatment interventions, and prognosis have been discussed. As it can be confused with other benign and malignant conditions, diagnosis is often made on histopathological evaluation.

BackgroundData on the clinical features, optimal treatment and outcomes of paediatric patients with epithelioid sarcoma (ES) are limited and mostly retrospective.MethodsA subset analysis of ES patients

Objective: The prognostic factors for patients with epithelial sarcoma remain unclear. The study aims to develop a practical clinical nomogram that predicts prognosis in patients with ES using the Surveillance, Epidemiology, and End Results (SEER) database. Methods: We extracted clinical data from 2004 to 2015 from the SEER database about patients with ES. All patients were randomly divided into training cohort and validation cohort. Kaplan–Meier analyses were used to compare outcomes between different subgroups. In order to estimate the chance of survival for patients with ES, we developed a nomogram. Nomogram performance was evaluated by discrimination and calibration. Additionally, an analysis of decision curves was conducted to evaluate the clinical usefulness of this newly developed model. Results: In the primary cohort,320 met the inclusion criteria to be entered into this study. The median OS was 66.000 months (range 34.704 to 94.296 months), and the 1‐, 3‐, and 5‐year OS rates were 70.7%, 56.1%, and 50.4%, respectively. For the validation cohort, we studied 136 consecutive patients. Age, primary site, grade, AJCC (American Joint Committee on Cancer) T, AJCC M, and surgery were included in the nomogram. The C‐index values for the training set and validation set were 0.817 and 0.832, respectively. The calibration plots showed good agreement between the prediction and the observation. Based on the clinical decision curve, the model has a good clinical net benefit for ES patients. Conclusions: It is the first study that developed an effective survival prediction model for patients with ES. Using this nomogram can assist in clinical decision‐making as it has satisfactory accuracy. Even so, additional external validation is needed. [ABSTRACT FROM AUTHOR]

Epithelioid sarcoma (ES) is a very rare and aggressive mesenchymal tumor of unclear origin and uncertain lineage characterized by a prevalent epithelioid morphology. The only recurrent genetic alteration reported in ES as yet is the functional inactivation of SMARCB1 (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1), a key component of the SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodeling complexes. How SMARCB1 deficiency dictates the clinicopathological characteristics of ES and what other molecular defects concur to its malignant progression is still poorly understood. This review summarizes the recent findings about ES pathobiology, including defects in chromatin remodeling and other signaling pathways and their role as therapeutic vulnerabilities. [ABSTRACT FROM AUTHOR]

Epithelioid sarcoma (ES) is a rare soft tissue tumor that is commonly misdiagnosed. It is a mesenchymal tumor that shows both mesenchymal and epithelial features. It tends to occur in the distal upper extremity in children and young adults but may appear in any location and any age group. Less than 1% of ES involve the head and neck. Clinically, the tumor can be mistakenly confused with a benign lesion as it can mimic nonspecific ulcers or infected warts. Histologically, ES is characterized by a nodular architecture and epithelioid appearance of cells centered with necrosis, mimicking a granulomatous process. We present the clinical history of a 12-year-old male who presented with an ES of the pretragus with a brief review of the literature to raise awareness on this rare entity and to discuss the challenges in managing histopathological differential diagnosis in front of this unusual clinical presentation., Competing Interests: None declared., (Published by Oxford University Press and JSCR Publishing Ltd. © The Author(s) 2024.)

Aim: Clinicopatholgical findings and outcomes in epithelioid sarcoma (ES) patients. Materials & methods: ES patients registered in sarcoma clinic from 2015 to 2021. Results: There were 20 patients with median age of 26 years. Majority had distal ES (70%) and advanced disease (85%). In patients with advanced disease lymph nodes were involved in 65%, lungs in 58% and others in 35%. Among 14 patients who underwent biopsy outside our institute, nine (64.2 %) had been initially misdiagnosed. Response rates to doxorubicin (n = 12), pazopanib (n = 6), gemcitabine/docetaxel (n = 5), tazemetostat (n = 3) and immunotherapy (n = 2) used in various lines were 16, 16, 20, 33 and 0%, respectively. Conclusion: Our patients had an advanced-stage and distal ES, with a modest response to chemotherapy.

Background: Metastatic epithelioid sarcoma (EPS) remains a largely unmet clinical need in children, adolescents and young adults despite the advent of EZH2 inhibitor tazemetostat. Methods: In order to realise consistently effective drug therapies, a functional genomics approach was used to identify key signalling pathway vulnerabilities in a spectrum of EPS patient samples. EPS biopsies/surgical resections and cell lines were studied by next‐generation DNA exome and RNA deep sequencing, then EPS cell cultures were tested against a panel of chemical probes to discover signalling pathway targets with the most significant contributions to EPS tumour cell maintenance. Results: Other biologically inspired functional interrogations of EPS cultures using gene knockdown or chemical probes demonstrated only limited to modest efficacy in vitro. However, our molecular studies uncovered distinguishing features (including retained dysfunctional SMARCB1 expression and elevated GLI3, FYN and CXCL12 expression) of distal, paediatric/young adult‐associated EPS versus proximal, adult‐associated EPS. Conclusions: Overall results highlight the complexity of the disease and a limited chemical space for therapeutic advancement. However, subtle differences between the two EPS subtypes highlight the biological disparities between younger and older EPS patients and emphasise the need to approach the two subtypes as molecularly and clinically distinct diseases. [ABSTRACT FROM AUTHOR]

Abstract Background Epithelioid sarcoma most frequently occurs in the dermal or subcutaneous area of the distal extremities. To date, there have been three cases of primary pulmonary epithelioid sarcoma reported. We report a case of epithelioid sarcoma that is considered a primary lung tumor. Case presentation A 65-year-old asymptomatic Asian male patient underwent chest radiography during a routine health examination, and an abnormal mass was detected. His past medical history was unremarkable. He smoked 40 cigarettes every day and had slightly obstructive impairment on spirometry. He worked as an employee of a company and had no history of asbestos exposure. He underwent partial resection of the right lung by thoracoscopy. A histological examination of the tumor revealed a cellular nodule of epithelioid and spindle-shaped cells. Some of the tumor cells displayed rhabdoid features and reticular arrangement in a myxomatous stroma. Immunohistochemically, the tumor cells were positive for vimentin, smooth muscle actin (SMA), CD34, and epithelial membrane antigen (EMA); loss of the BAF47/INI1 protein in the tumor cells was also confirmed. A diagnosis of epithelioid sarcoma was established. Careful screening by whole-body positron emission tomography for another primary lesion after surgery did not detect any possible lesion. He had no cutaneous disease. Conclusion To our knowledge, this is the fourth case of a proximal-type epithelioid sarcoma considered as a primary lung tumor.

Abstract Background Epithelioid sarcomas and rhabdoid tumors are rare, aggressive malignancies with poor prognosis. Both are characterized by INI1 alterations and deregulation of growth factor receptors albeit their interaction has not been elucidated. Methods In this study, we investigated the activity of a panel of epigenetic modulators and receptor tyrosine kinase inhibitors in vitro on respective cell lines as well as on primary patient-derived epithelioid sarcoma cells, and in vivo on xenografted mice. Focusing on histone deacetylase (HDAC) inhibitors, we studied the mechanism of action of this class of agents, its effect on growth factor receptor regulation, and changes in epithelial-to-mesenchymal transition by using cell- and RT-qPCR-based assays. Results Pan-HDAC inhibitor panobinostat exhibited potent anti-proliferative activity at low nanomolar concentrations in A204 rhabdoid tumor, and VAESBJ/GRU1 epithelioid sarcoma cell lines, strongly induced apoptosis, and resulted in significant tumor growth inhibition in VAESBJ xenografts. It differentially regulated EGFR, FGFR1 and FGFR2, leading to downregulation of EGFR in epithelioid sarcoma and to mesenchymal-to-epithelial transition whereas in rhabdoid tumor cells, EGFR was strongly upregulated and reinforced the mesenchymal phenotype. All three cell lines were rendered more susceptible towards combination with EGFF inhibitor erlotinib, further enhancing apoptosis. Conclusions HDAC inhibitors exhibit significant anticancer activity due to their multifaceted actions on cytotoxicity, differentiation and drug sensitization. Our data suggest that the tailored, tissue-specific combination of HDAC inhibitors with therapeutics which target cellular salvage mechanisms might increase their therapeutic relevance.

Epithelioid sarcoma (ES) is a rare, clinically polymorphic tumor that afflicts the dermal and subcutaneous region of distal extremity of young adults. In the distal extremity, the involvement of pubic and inguinal region is very rare. We present a case of an epithelioid sarcoma of the pubic region, which was managed, with a combination of upfront surgery and adjuvant therapy, and is presently disease free 5 years after completion of treatment.

Abstract Background Metastatic epithelioid sarcoma (EPS) remains a largely unmet clinical need in children, adolescents and young adults despite the advent of EZH2 inhibitor tazemetostat. Methods In order to realise consistently effective drug therapies, a functional genomics approach was used to identify key signalling pathway vulnerabilities in a spectrum of EPS patient samples. EPS biopsies/surgical resections and cell lines were studied by next‐generation DNA exome and RNA deep sequencing, then EPS cell cultures were tested against a panel of chemical probes to discover signalling pathway targets with the most significant contributions to EPS tumour cell maintenance. Results Other biologically inspired functional interrogations of EPS cultures using gene knockdown or chemical probes demonstrated only limited to modest efficacy in vitro. However, our molecular studies uncovered distinguishing features (including retained dysfunctional SMARCB1 expression and elevated GLI3, FYN and CXCL12 expression) of distal, paediatric/young adult‐associated EPS versus proximal, adult‐associated EPS. Conclusions Overall results highlight the complexity of the disease and a limited chemical space for therapeutic advancement. However, subtle differences between the two EPS subtypes highlight the biological disparities between younger and older EPS patients and emphasise the need to approach the two subtypes as molecularly and clinically distinct diseases.

Background: Although biological resources are essential for basic and preclinical research in the oncological field, those of sarcoma are not sufficient for rapid development of the treatment. So far, some sarcoma cell lines have been established, however, the success rate was low and the established sarcoma types were frequently biased. Therefore, an efficient culture method is needed to determine the various types of sarcomas. Organoid culture is a 3-dimentional culture method that enables the recapitulation of the tumor microenvironment and the success rate reported is higher than the 2-dimentional culture. The purpose of this study was to report our newly established organoids from human epithelioid sarcoma using the air-liquid interface organoid culture method. Methods: We treated 2 patients with epithelioid sarcoma in our institute. The remaining sarcoma specimens after surgical resection were embedded in collagen type 1 gels according to the air-liquid interface organoid culture method. After serial passages, we xenografted the organoids to NOD-scid IL2Rgnull (NSG) mice. Using the developed tumors, we performed histological and genomic analyses to compare the similarities and differences with the original epithelioid sarcoma from the patient. Results: Organoids from the epithelioid sarcoma could be serially cultured and maintained in collagen type 1 gels for more than 3 passages. Developed orthotopic tumor xenografts were detected in the NSG mice. After the process was repeated severally, the patient derived organoid lines from the epithelioid sarcoma were established. The established organoids showed loss of integrase interactor 1 expression with polymerase chain reaction and immunohistochemical analyses. The xenografted organoids of the epithelioid sarcoma had histologically similar phenotypes with the original tumor and genetically resembled it to some degree. Conclusions: The present study demonstrated 2 novel established organoid models of epithelioid sarcoma, and our organoid models could be used to investigate the molecular pathogenesis and develop a novel treatment. [ABSTRACT FROM AUTHOR]

Mutations in subunits of the SWItch Sucrose Non-Fermentable (SWI/SNF) complex occur in 20% of all human tumors. Among these, the core subunit SMARCB1 is the most frequently mutated, and SMARCB1 loss represents a founder driver event in several malignancies, such as malignant rhabdoid tumors (MRT), epithelioid sarcoma, poorly differentiated chordoma, and renal medullary carcinoma (RMC). Intriguingly, SMARCB1-deficient pediatric MRT and RMC have recently been reported to be immunogenic, despite their very simple genome and low tumor mutational burden. Responses to immune checkpoint inhibitors have further been reported in some SMARCB1-deficient diseases. Here, we will review the preclinical data and clinical data that suggest that immunotherapy, including immune checkpoint inhibitors, may represent a promising therapeutic strategy for SMARCB1-defective tumors. We notably discuss the heterogeneity that exists among the spectrum of malignancies driven by SMARCB1-loss, and highlight challenges that are at stake for developing a personalized immunotherapy for these tumors, notably using molecular profiling of the tumor and of its microenvironment. [ABSTRACT FROM AUTHOR]

The pathology of poorly differentiated sinonasal malignancies has been the subject of extensive studies during the last decade, which resulted into significant developments in the definitions and histo-/pathogenetic classification of several entities included in the historical spectrum of "sinonasal undifferentiated carcinomas (SNUC)" and poorly differentiated unclassified carcinomas. In particular, genetic defects leading to inactivation of different protein subunits in the SWI/SNF chromatin remodeling complex have continuously emerged as the major (frequently the only) genetic player driving different types of sinonasal carcinomas. The latter display distinctive demographic, phenotypic and genotypic characteristics. To date, four different SWI/SNF-driven sinonasal tumor types have been recognized: SMARCB1(INI1)-deficient carcinoma (showing frequently non-descript basaloid, and less frequently eosinophilic, oncocytoid or rhabdoid undifferentiated morphology), SMARCB1-deficient adenocarcinomas (showing variable gland formation or yolk sac-like morphology), SMARCA4-deficient carcinoma (lacking any differentiation markers and variably overlapping with large cell neuroendocrine carcinoma and SNUC), and lastly, SMARCA4-deficient sinonasal teratocarcinosarcoma. These different tumor types display highly variable immunophenotypes with SMARCB1-deficient carcinomas showing variable squamous immunophenotype, while their SMARCA4-related counterparts lack such features altogether. While sharing same genetic defect, convincing evidence is still lacking that SMARCA4-deficient carcinoma and SMARCA4-deficient teratocracinosarcoma might belong to the spectrum of same entity. Available molecular studies revealed no additional drivers in these entities, confirming the central role of SWI/SNF deficiency as the sole driver genetic event in these aggressive malignancies. Notably, all studied cases lacked oncogenic IDH2 mutations characteristic of genuine SNUC. Identification and precise classification of these entities and separating them from SNUC, NUT carcinoma and other poorly differentiated neoplasms of epithelial melanocytic, hematolymphoid or mesenchymal origin is mandatory for appropriate prognostication and tailored therapies. Moreover, drugs targeting the SWI/SNF vulnerabilities are emerging in clinical trials. [ABSTRACT FROM AUTHOR]

BackgroundAlthough biological resources are essential for basic and preclinical research in the oncological field, those of sarcoma are not sufficient for rapid development of the treatment. So far, some sarcoma cell lines have been established, however, the success rate was low and the established sarcoma types were frequently biased. Therefore, an efficient culture method is needed to determine the various types of sarcomas. Organoid culture is a 3-dimentional culture method that enables the recapitulation of the tumor microenvironment and the success rate reported is higher than the 2-dimentional culture. The purpose of this study was to report our newly established organoids from human epithelioid sarcoma using the air-liquid interface organoid culture method.MethodsWe treated 2 patients with epithelioid sarcoma in our institute. The remaining sarcoma specimens after surgical resection were embedded in collagen type 1 gels according to the air-liquid interface organoid culture method. After serial passages, we xenografted the organoids to NOD-scid IL2Rgnull (NSG) mice. Using the developed tumors, we performed histological and genomic analyses to compare the similarities and differences with the original epithelioid sarcoma from the patient.ResultsOrganoids from the epithelioid sarcoma could be serially cultured and maintained in collagen type 1 gels for more than 3 passages. Developed orthotopic tumor xenografts were detected in the NSG mice. After the process was repeated severally, the patient derived organoid lines from the epithelioid sarcoma were established. The established organoids showed loss of integrase interactor 1 expression with polymerase chain reaction and immunohistochemical analyses. The xenografted organoids of the epithelioid sarcoma had histologically similar phenotypes with the original tumor and genetically resembled it to some degree.ConclusionsThe present study demonstrated 2 novel established organoid models of epithelioid sarcoma, and our organoid models could be used to investigate the molecular pathogenesis and develop a novel treatment.

We present a case (41 years old pregnant female) with epithelioid sarcoma arising in the left external auditory canal. On immunohistochemistry, the tumor cell diffusely expressed cytokeratins and showed patchy expression of ERG and CD34. The neoplastic cells demonstrated uniform loss of INI1-expression. Epithelioid sarcoma arising in the external auditory canal is rare. Awareness that ES may rarely arise at unusual sites is of critical importance in order to apply a broad enough panel in the immunohistochemical study, so a misdiagnosis of carcinoma can be avoided. [ABSTRACT FROM AUTHOR]

Abstract Background The evidence that albumin-bound paclitaxel (nab-paclitaxel) is safe and efficacious for the treatment of many types of malignant tumors is continuously increasing. However, the evidence and clinical data of nab-paclitaxel and gemcitabine in metastatic soft tissue sarcoma (STS) treatment are rare. Methods The clinical data of metastatic STS patients who received nab-paclitaxel/ gemcitabine chemotherapy between January 2019 and February 2020 were retrospectively analysed. All these patients were treated with nab-paclitaxel/ gemcitabine only after doxorubicin-based chemotherapy had failed. We evaluated the effectiveness and safety of nab-paclitaxel and gemcitabine in these patients. Results A total of 17 patients treated with nab-paclitaxel/ gemcitabine were enrolled in this study. One patient with angiosarcoma achieved complete response, 6 patients had partial response, 5 patients achieved stable disease, and 5 patients had progressive disease. The average diameter change in target lesion from baseline was − 19.06 ± 45.74%. And median progression free survival was 6 months (95% CI, 2–9 months). Grade 3 / 4 adverse events were not common, included neutropenia (17.6%), fatigue (11.8%), anemia (11.8%), leukopenia (11.8%), nausea (5.9%), peripheral neuropathy (5.9%), diarrhea (5.9%), and thrombocytopenia (5.9%). No treatment-related deaths occurred. Conclusion Nab-paclitaxel/ gemcitabine combination chemotherapy is comparatively effective in the treatment of STS, demonstrates low toxicity, and is worthy of further study.

A cranioplasty has a number of known associated complications including infection for non-biological implants and bone flap resorption where autologous grafts are used. In recent years, bioactive ceramic cranial implants have been developed as a new reconstructive option. The OssDsign cranial plate (OssDsign AB, Uppsala, Sweden) was first introduced in 2010 and consists of an interconnected mosaic of hydroxyapatite tiles mounted onto a 3D-printed titanium mesh. Each tile is composed of a monetite, beta-calcium pyrophosphate, beta-tricalcium phosphate and brushite compound designed to mimic the process of coupled bone formation once implanted.This case presents a patient's journey from diagnosis of an epithelioid sarcoma over the posterior scalp and its management in the following 7 years. Initial excision of the lesion was reconstructed with a tissue expander and local rotational flap. Recurrence of the disease 3 years later was treated with a course of radical radiotherapy. Persistent osteomyelitis over the next 3 years resulted in chronic ulceration and exposed bone in the treated area. As the first part of a 3-stage treatment plan, two separate tissue expanders became infected. The multidisciplinary team therefore chose to use a bespoke OssDsign cranial plate combined with a deep inferior epigastric perforator (DIEP) free flap to provide a definitive single operative solution. The advantages over other reconstruction options include that the plate can be removed should further excision be required, greater potential for long-term integration with surrounding tissues and the ability to be soaked in antibiotic to reduce the risk of infection.

Epithelioid sarcoma (ES) is a rare soft tissue neoplasm with high recurrence rates. Wide surgical resection remains the only potential curative treatment. ES presents most commonly on the fingers, hands and forearm, making light-based cancer cell-targeted therapies such as near-infrared photoimmunotherapy (NIR-PIT) that is target-specific, but with limited penetration depth, suitable for ES treatment. We established that CD44 and EGFR were overexpressed in ES patient samples and in the VA-ES-BJ human ES cell line. NIR-PIT of VA-ES-BJ cells using antibody photosensitizer conjugates, prepared by conjugating a CD44 or EGFR monoclonal antibody to the photosensitizer IR700, confirmed that NIR-PIT with both conjugates resulted in cell death. Neither treatment with NIR light alone nor treatment with the conjugates but without NIR light were effective. CD44-IR700-PIT resulted in greater cell death than EGFR-IR700-PIT, consistent with the increased expression of CD44 by VA-ES-BJ cells. In tumors, EGFR-IR700 exhibited a higher tumor-to-normal ratio, as determined by in vivo fluorescence imaging, and a higher anti-tumor growth effect, compared to CD44-IR700. No antitumor effect of the EGFR antibody or the photosensitizer conjugate alone was observed in vivo. Our data support evaluating the use of EGFR-IR700-PIT in the management of ES for detecting and eliminating ES cells in surgical margins, and in the treatment of superficial recurrent tumors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Epithelioid sarcoma (ES) is a rare soft tissue sarcoma (STS), with limited therapies available for metastatic disease. Here, we describe a case of a 30-year-old male with ES of the left knee and underwent surgery and radiation therapy for the primary disease. After 2 years, he had local recurrence and underwent extensive resection surgery; however, adjuvant chemotherapies were delayed due to recurrent wound infection. Nine months after the second surgery, progressive disease was confirmed after detection of metastases to the lungs and inguinal lymph nodes. Amputation was performed for the local recurrence, followed by inguinal lymph nodes dissection. Pazopanib was transiently administered but discontinued as a result of wound dehiscence. The tumour specimens were detected with unexpected high level of PD-L1 expression and tumoural infiltrating lymphocytes. Subsequently, he received camrelizumab 2.0 mg/kg every 21 days for 18 cycles with rapid remission of the pulmonary metastases. This promising response to camrelizumab indicates that immunotherapies may be an alternative choice for patients with metastatic ES in lung based on analysing the tumour immune microenvironment. [ABSTRACT FROM AUTHOR]

A 33-year-old male presented with a one-centimetre lesion at the penoscrotal junction which was excised and revealed to be an epithelioid sarcoma (ES). A wide local excision of the lesion and subsequent neoadjuvant radiotherapy followed, with transposition of the patient's testicles laterally to protect fertility. At 3-year follow-up, the patient has no local or distant recurrence but does have a low sperm count. The patient has also had intermittent haematospermia since his treatment for which a cause has yet to be identified. This case highlights that ES of the penis can be managed successfully with surgical excision and local radiotherapy.

Epithelioid sarcoma (ES) is a rare soft tissue sarcoma (STS), with limited therapies available for metastatic disease. Here, we describe a case of a 30-year-old male with ES of the left knee and underwent surgery and radiation therapy for the primary disease. After 2 years, he had local recurrence and underwent extensive resection surgery; however, adjuvant chemotherapies were delayed due to recurrent wound infection. Nine months after the second surgery, progressive disease was confirmed after detection of metastases to the lungs and inguinal lymph nodes. Amputation was performed for the local recurrence, followed by inguinal lymph nodes dissection. Pazopanib was transiently administered but discontinued as a result of wound dehiscence. The tumour specimens were detected with unexpected high level of PD-L1 expression and tumoural infiltrating lymphocytes. Subsequently, he received camrelizumab 2.0 mg/kg every 21 days for 18 cycles with rapid remission of the pulmonary metastases. This promising response to camrelizumab indicates that immunotherapies may be an alternative choice for patients with metastatic ES in lung based on analysing the tumour immune microenvironment.

Epithelioid sarcoma (ES) is a rarely occurring malignant soft tissue tumor of uncertain histogenesis. It is most common among young males and commonly seen on the forearm, hand, and fingers. ES begins as a small lump or ulcer, and most were painless. ES has a high rate of recurrence and can spread to other parts of the body easily. Hence, physicians should take the necessary steps to ensure proper diagnosis and treatment. We present an interesting case of a 26-year-old male diagnosed with a proximal variant of ES of the shoulder.

Epithelioid sarcomas (ESs) of the vulva are extremely rare soft tissue tumors characterized by an aggressive clinical course and a poor prognosis. The proximal type of ES occurs in the trunk and external genital area and has higher recurrence and distant metastasis rates than the distal type, which is found in the upper and lower extremities. We describe a case of a vulvar ES in a 24-year-old patient who was referred from the department of plastic surgery with protruding mushroom-like lesions in multiple areas, including the lower abdomen, whole vulva, anus, and both inguinal lesions. A biopsy of the lesions confirmed a proximal-type ES. Computed tomography and magnetic resonance imaging revealed multiple metastatic lesions in several regions, including the perineum, vagina, and inguinal regions; nodal metastases in the left external iliac and right inguinal region; and distant metastases in the lungs, pleura of the left lung, bones, and soft tissue. The patient underwent active palliative radiotherapy, followed by chemotherapy, and showed a partial response to treatment. Nineteen months after the initial diagnosis, the patient expired due to cancer progression and pneumothorax.

Background: Epithelioid sarcomas and rhabdoid tumors are rare, aggressive malignancies with poor prognosis. Both are characterized by INI1 alterations and deregulation of growth factor receptors albeit their interaction has not been elucidated.Methods: In this study, we investigated the activity of a panel of epigenetic modulators and receptor tyrosine kinase inhibitors in vitro on respective cell lines as well as on primary patient-derived epithelioid sarcoma cells, and in vivo on xenografted mice. Focusing on histone deacetylase (HDAC) inhibitors, we studied the mechanism of action of this class of agents, its effect on growth factor receptor regulation, and changes in epithelial-to-mesenchymal transition by using cell- and RT-qPCR-based assays.Results: Pan-HDAC inhibitor panobinostat exhibited potent anti-proliferative activity at low nanomolar concentrations in A204 rhabdoid tumor, and VAESBJ/GRU1 epithelioid sarcoma cell lines, strongly induced apoptosis, and resulted in significant tumor growth inhibition in VAESBJ xenografts. It differentially regulated EGFR, FGFR1 and FGFR2, leading to downregulation of EGFR in epithelioid sarcoma and to mesenchymal-to-epithelial transition whereas in rhabdoid tumor cells, EGFR was strongly upregulated and reinforced the mesenchymal phenotype. All three cell lines were rendered more susceptible towards combination with EGFF inhibitor erlotinib, further enhancing apoptosis.Conclusions: HDAC inhibitors exhibit significant anticancer activity due to their multifaceted actions on cytotoxicity, differentiation and drug sensitization. Our data suggest that the tailored, tissue-specific combination of HDAC inhibitors with therapeutics which target cellular salvage mechanisms might increase their therapeutic relevance. [ABSTRACT FROM AUTHOR]

Background: Epithelioid sarcoma most frequently occurs in the dermal or subcutaneous area of the distal extremities. To date, there have been three cases of primary pulmonary epithelioid sarcoma reported. We report a case of epithelioid sarcoma that is considered a primary lung tumor. Case presentation: A 65-year-old asymptomatic Asian male patient underwent chest radiography during a routine health examination, and an abnormal mass was detected. His past medical history was unremarkable. He smoked 40 cigarettes every day and had slightly obstructive impairment on spirometry. He worked as an employee of a company and had no history of asbestos exposure. He underwent partial resection of the right lung by thoracoscopy. A histological examination of the tumor revealed a cellular nodule of epithelioid and spindle-shaped cells. Some of the tumor cells displayed rhabdoid features and reticular arrangement in a myxomatous stroma. Immunohistochemically, the tumor cells were positive for vimentin, smooth muscle actin (SMA), CD34, and epithelial membrane antigen (EMA); loss of the BAF47/INI1 protein in the tumor cells was also confirmed. A diagnosis of epithelioid sarcoma was established. Careful screening by whole-body positron emission tomography for another primary lesion after surgery did not detect any possible lesion. He had no cutaneous disease. Conclusion: To our knowledge, this is the fourth case of a proximal-type epithelioid sarcoma considered as a primary lung tumor. [ABSTRACT FROM AUTHOR]

Abstract Background Epithelioid sarcoma (ES) is a rare malignant soft tissue tumor, commonly occurring in distal extremities, such as fingers, hands and wrists. For oncologists and surgeons, a female patient with enlarged axillary lymph node on one side only is easily diagnosed with an occult breast carcinoma rather than ES. Besides, whole breast metastasis of ES has not been reported yet. Case presentation A 47-year-old Chinese woman came to the outpatient clinic of First Affiliated Hospital of Zhejiang University (FAHZU) with a complaint of an asymptomatic right axillary mass for 3 months. Then she received surgical resection of the right axillary lymph nodes and right supraclavicular lymph nodes. According to the clinical tumor site and routine immunohistochemistry (IHC), suspicion of metastatic epithelial sarcoma and metastatic breast cancer could not be ruled out. Subsequently, with more detailed medical history review and physical examination, a mass on the right forearm was found, which was considered as the primary lesion. Further IHC and Molecular Genetics revealed that all the neoplastic cells exhibited loss of INI1 protein and were negative for ERG gene rearrangement yet positive for epithelial membrane antigen (EMA), cytokeratin (CK) 8, CK19, Vimentin, CD34. The final diagnosis was ES. She received postoperative chemotherapy, without radiotherapy. Unexpectedly, an ipsilateral breast metastasis was developed at ten months after surgery. Regrettably, there was no positive result of the metastatic breast sample, based on a genome sequencing by a 381-cancer-gene panel in a lab. Therefore, she went through another round of chemotherapy and took Apatinib for maintenance treatment. During the last follow-up (26 months after diagnosis), the disease was under control. Conclusion This rare but interesting case enables breast surgeons and pathologists to accumulate more experience of differential diagnosis of axillary mass for personalized treatment in clinical practice. Meanwhile, ipsilateral breast metastasis of ES we reported in the case urges that clinicians attach greater importance to the tumor metastasis mechanism.

Epithelioid sarcoma (ES) is a very rare and aggressive mesenchymal tumor of unclear origin and uncertain lineage characterized by a prevalent epithelioid morphology. The only recurrent genetic alteration reported in ES as yet is the functional inactivation of SMARCB1 (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1), a key component of the SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodeling complexes. How SMARCB1 deficiency dictates the clinicopathological characteristics of ES and what other molecular defects concur to its malignant progression is still poorly understood. This review summarizes the recent findings about ES pathobiology, including defects in chromatin remodeling and other signaling pathways and their role as therapeutic vulnerabilities.