Epithelioid Sarcoma: Diagnostic Features and Genetics

Extra-Axial Poorly Differentiated Chordoma Initially Misdiagnosed as Epithelioid Sarcoma

Poorly differentiated chordoma is an exceedingly rare, aggressive subtype of chordoma. These tumors typically arise in the axial skeleton of young patients, most commonly the skull base, followed by the cervical spine. Herein, we present a 60-year-old patient with longstanding knee pain and nondiagnostic imaging, initially thought to be due to osteoarthritis. No discrete mass-forming lesion was identified by radiology. Synovial histology at the time of arthroplasty revealed a multinodular proliferation of epithelioid-to-histiocytoid cells with a moderate amount of eosinophilic-to-clear, vacuolated cytoplasm. Scattered cells with high-grade nuclear atypia were present. A diagnosis of metastatic carcinoma was considered due to immunohistochemical positivity for keratin and GATA3. However, a diagnosis of epithelioid sarcoma was rendered based on clinical context, morphology, and loss of immunohistochemical expression for SMARCB1 (INI1). However, upon re-review of the tumor, brachyury was retrospectively added to the immunohistochemistry panel and showed strong positivity, thus prompting amendment of the initial diagnosis of epithelioid sarcoma to extra-axial poorly differentiated chordoma. Given the rarity of this diagnosis, molecular testing was performed which revealed a unique SMARCB1 molecular profile with a single-nucleotide variant in addition to the commonly reported loss of chromosome 22q. This report of an ultra-rare sarcoma in an uncommon anatomic site highlights multiple potential pitfalls in the diagnosis of poorly differentiated chordoma, emphasizes the importance of brachyury immunohistochemistry in rendering a correct interpretation, and underscores an opportunity for further molecular analysis to better define the molecular profile of this entity.

Proximal and Classic Epithelioid Sarcomas are Distinct Molecular Entities Defined by MYC/GATA3 and SOX17/Endothelial Markers, Respectively

Epithelioid sarcoma (ES) is a rare tumor hallmarked by the loss of INI1/SMARCB1 expression. Apart from this alteration, little is known about the biology of ES. Despite recent advances in treatment, the prognosis of ES remains unsatisfactory. To elucidate the molecular underpinnings of ES, and to identify diagnostic biomarkers and potential therapeutic vulnerabilities, we performed an integrated omics profiling (RNA sequencing and methylation array) of 24 primary, untreated ESs. Transcriptome and methylome analysis identified 2 distinct molecular clusters that essentially corresponded to the morphologic variants of ES, classic ES (C-ES) and the more aggressive proximal ES (P-ES). The P-ES group was characterized by hyperactivation of GATA3 and MYC pathways, with extensive epigenetic rewiring associated with EZH2 overexpression. Both DNA methylation and gene expression analysis indicated a striking similarity with the "MYC subgroup" of atypical teratoid/rhabdoid tumor, another SMARCB1-deficient tumor, implying a shared molecular background and potential therapeutic vulnerabilities. Conversely, the C-ES group exhibited an endothelial-like molecular profile, with expression of vascular genes and elevated proangiogenic SOX17 signaling. Immunohistochemistry validated the overexpression of the chromatin regulators GATA3 (9/12 vs 0/16) and EZH2 (7/7 vs 2/6) in P-ESs, and of the vascular factors SOX17 (8/8 vs 1/10) and N-cadherin (5/9 vs 0/10) in C-ESs. Therefore, these molecules emerge as potential diagnostic tools to fill the gap represented by the lack of ES subtype-specific biomarkers. In summary, our study shows that P-ES and C-ES represent distinct molecular entities defined by MYC/GATA3 and SOX17/endothelial molecular traits, respectively. Besides providing insights into the biology of ES, our study pinpoints subtype-specific biomarkers and potential therapeutic vulnerabilities.

Epithelioid sarcoma: a rare cause of refractory chronic skin ulcers

We report two cases of chronic skin ulcers that were misdiagnosed as skin and soft tissue infections and as an inflammatory myofibroblastic tumour before the final diagnosis of epithelioid sarcoma at our institution. Our coverage of this rare but fatal tumour that can cause chronic skin ulcers is critical because early diagnosis and treatment can reduce morbidity and mortality.

Primary adenocarcinoma of the spermatic cord: a case report and review of the literature

BACKGROUND

Primary malignant neoplasms of the spermatic cord are extremely rare, with most reported cases being sarcomas or metastatic carcinomas. However, primary adenocarcinoma of the spermatic cord has not been previously reported.

CASE PRESENTATION

A 34-year-old male with a solid mass in the right spermatic cord, was eventually diagnosed with primary adenocarcinoma. Histological examination revealed a moderately-to-poorly differentiated adenocarcinoma exhibiting glandular, cribriform, or nested growth patterns, characterized by medium to large-sized cells and focal extracellular mucus. Immunohistochemical analysis demonstrated positive staining for CK (AE1/AE3), CK8/18, CK19, MOC31 (EP-CAM), and Ber-EP4, while negative staining was observed for CK7, D2-40, WT-1, MC, PAX-8, NKX3.1, PSA, CEA, TTF-1, and NapsinA. Furthermore, a complete loss of INI-1 expression and consistent BRG1 expression were noted in all tumor cells. Next-generation sequencing revealed SMARCB1 deletion, low tumor mutation burden (TMB-L), and microsatellite stability (MSS).

CONCLUSION

We reported the first case of primary adenocarcinoma of the spermatic cord with SMARCB1 (INI-1) deficiency. This case contributes to the expanding understanding of rare neoplasms and underscores the importance of further research into therapeutic strategies targeting SMARCB1-deficient tumors.

Spitz melanoma with MAP3K8::ABLIM1 rearrangement: a case report with review of the literature

BACKGROUND

Spitz tumors are relatively uncommon melanocytic lesions, typically affecting a relatively younger population but can be encountered at any age. They are characterized by a proliferation of melanocytes with epithelioid and/or spindled cytomorphology features, and interpretation is often challenging. The majority of these tumors are driven by kinase fusions or HRAS mutations. MAP3K8 fusions, although rare, are characteristic genomic events in Spitz tumors, especially in more atypical or malignant lesions.

CASE PRESENTATION

Here, we present the case of a 43-year-old woman with a clinically cystic mass in her right groin, histologically characterized as a spindle and epithelioid cell malignant tumor. Immunohistochemistry revealed diffuse expression of S100 protein, tyrosinase and SOX10, patchy weak PRAME, HMB45 and Melan-A reactivity, and negative staining for BRAF V600E. Next-generation sequencing analysis revealed the presence of a MAP3K8::ABLIM1 fusion gene, as well as GRIN2A and TERT promoter mutations. The morphology, immunohistochemistry and molecular analysis confirmed Spitz melanoma with molecular features suggesting a worse prognosis.

CONCLUSION

This case introduces a novel fusion partner of MAP3K8 in the context of Spitz melanoma and expands the morphologic and molecular spectrum of Spitz melanoma.

Epithelioid sarcoma of the pretragus: a rare pediatric entity with an unusual site

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.

SMARCB1 (INI1) Deficient Tumours of the Uterine Cervix: Report of Two Cases, Including One Associated With an NTRK Fusion

Pathogenic variants (mutations) and other molecular events involving subunits of the SWItch/Sucrose Non-Fermentable chromatin remodelling complex are common in a wide variety of malignancies. Many of these neoplasms are characterized by undifferentiated morphology. They arise at a variety of sites in the female genital tract but have rarely been reported in the uterine cervix. We report 2 primary cervical neoplasms arising in young women (ages 28 and 29 yr) exhibiting loss of nuclear immunoreactivity with SMARCB1 (INI1). In one case, which had a mixture of epithelioid and spindle cells, molecular studies revealed no SMARCB1 pathogenic variant, but showed a SPECCL1::NTRK 3 fusion, in keeping with an NTRK fusion sarcoma. The second case exhibited rhabdoid morphology and molecular testing confirmed a SMARCB1 pathogenic variant (c.425 T>G:p.(Leu142Ter) which, interpreted in conjunction with the morphology and immunohistochemistry, resulted in classification as a proximal-type epithelioid sarcoma. To our knowledge, this is the first reported cervical neoplasm exhibiting a SMARCB1 pathogenic variant and the first NTRK fusion sarcoma showing SMARCB1 protein loss. We discuss the diagnostic challenges and complexities of the molecular findings.

Photoimmunotheranostics of epithelioid sarcoma by targeting CD44 or EGFR

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.

Sarcoma microenvironment cell states and ecosystems are associated with prognosis and predict response to immunotherapy

Characterization of the diverse malignant and stromal cell states that make up soft tissue sarcomas and their correlation with patient outcomes has proven difficult using fixed clinical specimens. Here, we employed EcoTyper, a machine-learning framework, to identify the fundamental cell states and cellular ecosystems that make up sarcomas on a large scale using bulk transcriptomes with clinical annotations. We identified and validated 23 sarcoma-specific, transcriptionally defined cell states, many of which were highly prognostic of patient outcomes across independent datasets. We discovered three conserved cellular communities or ecotypes associated with underlying genomic alterations and distinct clinical outcomes. We show that one ecotype defined by tumor-associated macrophages and epithelial-like malignant cells predicts response to immune-checkpoint inhibition but not chemotherapy and validate our findings in an independent cohort. Our results may enable identification of patients with soft tissue sarcomas who could benefit from immunotherapy and help develop new therapeutic strategies.

Primary adrenal epithelioid sarcoma (proximal type): a case report and literature review

Primary adrenal epithelioid sarcoma is a rare lesion of the adrenal gland, and only seven cases have been reported in the domestic and international literature to date. We herein report a case involving a 65-year-old man with primary adrenal epithelioid sarcoma. After being admitted to the hospital with an adrenal mass found on physical examination, the patient underwent laparoscopic right adrenalectomy. Postoperative pathological findings indicated an epithelioid sarcoma (proximal type). Primary adrenal epithelioid sarcoma is a rare malignancy. Diagnosis is challenging and relies on histopathology and immunohistochemical staining.

A unique case of epithelioid sarcoma involving the mandibular alveolar mucosa

Epithelioid sarcoma (ES) is an infrequent, malignant, mesenchymal, soft-tissue neoplasm of uncertain histogenesis characterized by epithelioid cytomorphology. The lack of SMARCB1/INI1 (Integrase interactor 1) expression typifies this pathology. It usually presents as a painless, indolent, slowly enlarging lesion or rarely as an aggressive growth. Epithelioid sarcoma affects mostly pediatric patients or young adults. It recurs quite frequently and possesses a high degree of metastatic potential. Two predominant histomorphologic patterns include classic/conventional type and proximal types. Epithelioid sarcoma immunohistochemically shows vimentin, cytokeratin, epithelial membrane antigen, CD34 positivity, and negative staining with S100 and desmin. Management is generally multimodal, including wide surgical resection, radiotherapy, and chemotherapy. To date, to our knowledge, only 11 instances of head and neck ES have been reported in the literature. Our case deals with the diagnosis of intraoral ES in a 55-year-old female patient, probably the first one to involve the mandibular mucosa, based on relevant clinical-radiologic-pathologic-immunohistochemical findings.

The over diagnosis of diffuse mesothelioma: An analysis of 311 cases with recommendations for the avoidance of pitfalls

BACKGROUND

The diagnosis of mesothelioma may be challenging. We investigated a large database of cases in order to determine the frequency with which a diagnosis of mesothelioma was made incorrectly and the most frequent causes of error.

DESIGN

A database including more than 4000 consultation cases of histologically confirmed mesothelioma was examined to identify cases in which mesothelioma was diagnosed by at least one pathologist when the available information pointed towards a different diagnosis.

RESULTS

There were 311 cases misdiagnosed as mesothelioma. The most common category was metastatic carcinoma to the pleura or peritoneum (129 cases: 73 lung carcinomas, 15 renal cell carcinomas). The next most common category was primary lung cancer (111 cases: 55 sarcomatoid carcinoma, 56 pseudomesotheliomatous carcinoma). The third most common category was primary malignancies arising from or near the serosal membranes (33 cases). The fourth most common category was fibrous pleurisy (38 cases). The most common errors were failure to consider important radiographic information regarding the gross distribution of tumor, lack of awareness or consideration of another malignancy, overreliance on certain immunohistochemical results, and failure to perform certain diagnostic histochemical, immunohistochemical, or ultrastructural studies.

CONCLUSIONS

There are a number of diagnostic pitfalls that can lead to the over diagnosis of mesothelioma. Careful attention to clinical and radiographic information as well as performance of appropriate ancillary tests can help to prevent such misdiagnoses. Detailed examples will be presented to assist in the avoidance of these pitfalls with emphasis on the most commonly observed errors.

Case report: The first account of undifferentiated sarcoma with epithelioid features originating in the pleura

Undifferentiated epithelioid sarcoma (USEF) is a rare subtype of undifferentiated soft tissue sarcoma that presents unique challenges in clinical diagnosis and treatment. Here, we report a case of USEF occurring in the pleura of a 51-year-old man for the first time. Thoracoscopic examination revealed widespread nodular changes, and pathological analysis confirmed the presence of numerous epithelioid atypical cells. Immunohistochemical (IHC) analysis demonstrated an undifferentiated phenotype with distinct characteristics: epithelial membrane antigen (foci +), vimentin (+), Ki-67 (+70% +), TTF-1 (+), P53 (mutant type +90%), INI-1 (+), and CK5/6 (small foci +). Immunohistochemical examination of the tumor showed that the tumor was an undifferentiated epithelioid sarcoma. High-throughput DNA sequencing revealed pivotal mutations, including a nonsense mutation in the NF1 gene (c.641A > G(p.H214R)). and critical TP53 missense mutation (c.641A > G(p.H214R)). This TP53 mutation, with a tumor mutation burden of 16.5 Muts/Mb, signifies a high level of genomic instability, likely contributing to the rapid progression and aggressiveness of the disease. Detection of the TP53 mutation provides essential insights, indicating the disease's rapid progression and highlighting the potential for targeted therapies. Although the patient's disease progressed extremely rapidly and he tragically died within a week, we discussed the results of IHC and DNA sequencing in detail and discussed his possible treatment options. Insights gained from this case will be critical in shaping future diagnostic and therapeutic paradigms for USEF, particularly in the context of TP53 mutations.

Abdominal rhabdoid tumor presenting with symptomatic spinal epidural compression in a newborn. A case report

The occurrence of an abdominal tumor invading the spinal canal and causing symptoms of epidural compression is rare in an infant, and exceptional at birth. Peripheral neuroblastic tumors are by far the most common cause. Emergency chemotherapy is commonly curative, though permanent sequelae are possible. Although other malignancies may be involved, no case of rhabdoid tumors at birth has been reported. We describe the case of a neonate who presented symptoms of spinal epidural compression at birth secondary to a rhabdoid tumor. As expected with this highly malignant tumor, the patient experienced a rapidly progressive clinical course and died within three months of diagnosis.

Delayed diagnosis of pediatric intra-articular epithelioid sarcoma: a case report and literature review

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.

Targeting epigenetic aberrations of sarcoma in CRISPR era

Sarcomas are rare malignancies that exhibit diverse biological, genetic, morphological, and clinical characteristics. Genetic alterations, such as gene fusions, mutations in transcriptional machinery components, histones, and DNA methylation regulatory molecules, play an essential role in sarcomagenesis. These mutations induce and/or cooperate with specific epigenetic aberrations required for the growth and maintenance of sarcomas. Appropriate mouse models have been developed to clarify the significance of genetic and epigenetic interactions in sarcomas. Studies using the mouse models for human sarcomas have demonstrated major advances in our understanding the developmental processes as well as tumor microenvironment of sarcomas. Recent technological progresses in epigenome editing will not only improve the studies using animal models but also provide a direct clue for epigenetic therapies. In this manuscript, we review important epigenetic aberrations in sarcomas and their representative mouse models, current methods of epigenetic editing using CRISPR/dCas9 systems, and potential applications in sarcoma studies and therapeutics.

Classic Type of Epithelioid Sarcoma of the Distal Upper Extremity: Clinical and Oncological Characteristics

BACKGROUND

The classic type of epithelioid sarcoma (ES) is a rare, aggressive soft tissue neoplasm that most commonly affects the distal upper extremities of young patients. This study aimed to assess clinical features and provide a long-term report of the oncological outcome.

METHODS

We retrospectively analyzed our clinical database for patients with ES of the distal upper extremities.

RESULTS

Twenty-three patients with ES of the distal upper extremity were treated surgically between January 1990 and August 2018. ES affected most commonly the palmar side of young patients. The most common site affected by a sarcoma was the wrist in 47.8% of cases, followed by metacarpals and fingers with 34.8% and 17.4%, respectively. Most of the patients were treated according to the protocols of interdisciplinary tumor boards with multimodal therapy. A local recurrence was observed in 7 patients (30.4%). The 5 - and 10-year recurrence-free survival was 80.4% (95% confidence interval [CI]: 68.6-76.8) and 60.9% (95% CI: 53.5-68.3), respectively. The 5- and 10-years disease-specific survival was 89.9% (95% CI: 87-92.8) and 61.9% (95% CI: 56.5-67.3), respectively. Five patients (21.7%) had metastasis in regional lymph nodes.

CONCLUSION

The classic type of ES represents a group of high-grade sarcomas, which affect the dominantly distal upper extremity. Specific clinical, diagnostic, and oncological characteristics make it difficult to diagnose and therapy. Wide tumor resection as a part of multimodal therapy remains a more viable and common treatment option for patients with ES on distal extremities. High rates of lymph node metastasis are typical for ES.

Metastatic Epithelioid Sarcoma of the Eyelid in a 47-Year-Old Man: A Case Report

Epithelioid sarcoma is a rare soft tissue neoplasm of uncertain differentiation that typically affects the distal extremities. Primary orbital epithelioid sarcoma is rare, and no reports exist characterizing metastases of this tumor to the orbit and ocular adnexa. In this article, the authors describe a rare case of eyelid metastasis in a 47-year-old man with epithelioid sarcoma of the right fibula diagnosed 16 months earlier who was otherwise doing well on the adjuvant tazemetostat therapy. In addition, the authors perform a retrospective review of cases of primary orbital epithelioid sarcoma reported in the literature, of which 4 patients responded favorably to surgical excision whereas 2 others eventually died as a direct result of their disease.

Primary Epithelioid Sarcoma of the Conchal Bowl in a 64-Year-Old Male: A Case Report and Review of the Literature

ABSTRACT

Epithelioid sarcoma (ES) is a distinctive malignant mesenchymal neoplasm with atypical epithelioid cells palisading around a central zone of necrosis. ES is a rare entity even in soft tissue pathology. Immunohistochemically, tumors usually show diffuse epithelial membrane antigen and cytokeratin expression and loss of nuclear INI1 (SMARCB1) expression. Here, we report a case of a 64-year-old man with ES arising in the left conchal bowl. Given the clinical presentation including patient's age, sun-exposed area of skin, and slow-growing, asymptomatic, small pink pearly papule, this patient was initially misdiagnosed with basal cell carcinoma clinically and treated with topical imiquimod at an outside facility. The lesion continued to grow and eventually became symptomatic despite the treatment after which biopsy was obtained. Despite the unusual anatomic site and the patient's age, the microscopic and immunohistochemical findings were characteristic of conventional-type ES. Our case shows that ES can arise in rare locations and in older adults where it may be more easily misdiagnosed clinically and pathologically as a nonmelanoma skin cancer.

Application of immunohistochemical studies in diagnosing emerging superficial mesenchymal neoplasms

Molecular diagnostics, with the subsequent development of novel immunohistochemical markers, continues to advance and expand the field of soft tissue pathology. As such, the ever-evolving molecular diagnostic landscape will continue to shape and refine our understanding and classification of neoplasms. This article reviews the current literature on various tumors of mesenchymal origin, including fibroblastic/fibrohistiocytic, adipocytic, vascular, and tumors of uncertain origin. We aim to give the reader a detailed understanding and pragmatic approach to various new and established immunohistochemical stains in diagnosing these neoplasms and also discuss various pitfalls with significant repercussions.

A multi-disciplinary team approach to pediatric malignant mandibular tumors

OBJECTIVE

Mandibular tumors in the pediatric population are rare. These malignancies are variable in their histology, and combined with their rarity, has made it difficult to describe their clinical course, and treatment guidelines. The aim of this paper is to describe the experience of Boston Children's Hospital, a pediatric tertiary referral center, with treating malignant mandibular malignancies, as well as provide multi-disciplinary team approach in managing this clinical entity.

METHODS

A retrospective search was performed for mandibular malignancies in pediatric patients between 1995 and 2020 via the pathological database at Boston Children's Hospital. Only patients with malignant solid mandibular neoplasms were included, leaving 15 patients for final analysis.

RESULTS

The median age at presentation was 10.1 ± 10.3 years. Nine of 15 patients (60%) presented with jaw mass which was the most common clinical presentation. The most commonly identified histological diagnosis was rhabdomayosarcoma and osteosarcoma (n = 4, 26% each). A mandibulectomy was performed in 12 (80%) cases. Reconstruction of the mandible was performed using a fibular free flap in 6 (40%) cases, and a plate in 3 (20%) cases. Mean follow-up was 4.6 ± 4.9 years.

CONCLUSION

Malignant tumors most commonly present with a jaw mass, however asymptomatic and incidental presentations follow closely and pathologies can vary greatly. Surgical resection and reconstruction is often indicated, multidisciplinary tumor board review is required to determine when children are best treated with neo-/adjuvant treatment with chemo- and radiotherapy.

Clinicopathological Characteristics, Treatment, and Survival in Patients Diagnosed With Proximal-Type Epithelioid Sarcoma: A Case Report and Systematic Review

Epithelioid sarcoma is a rare entity that shows a predilection for the young and middle-aged population. There are two subtypes, i.e., the distal or conventional type, which is located in distal extremities, and the proximal type, located in proximal areas of the extremities, pelvis, perineal, and genital region. The latter is characterized by more aggressive behavior, a higher recurrence rate, and poor prognosis. Histopathological and immunohistochemical diagnoses are key to correct and timely treatment and a higher survival rate. We report a case of a 41-year-old man who presented a palpable progressive growth mass in the hypogastrium. The disease time was of nine months, and the tumor was resected, but it recurred a few months later in the same location. Computed tomography (CT) scans showed images suggestive of lung metastasis and the patient had to undergo a second surgery. He received eight cycles of chemotherapy and a subsequent CT scan control showed the progression of the disease, so a new chemotherapy regimen was established. The patient received three cycles of chemotherapy without improvement, so he decided to discontinue treatment. His last outpatient medical consultation was in January 2022. A systematic review of the studies published in PubMed and Google Scholar was performed. We identified 291 articles, but only 41 reports and case series were included, with a total of 55 patients. It is important to include this type of tumor in the differential diagnosis of epithelial tumors due to its aggressive behavior. Correct and timely diagnosis is crucial to obtain lower recurrence rates, lower mortality, and higher survival rates in these patients.

Intra-abdominal epithelioid angiosarcoma

The epithelioid angiosarcoma is a type of sarcoma is very rare (<1 % of all sarcomas). The most frequent location is in extremities, therefore is the axial region less common.Differential diagnosis with other histologic variants of intra-abdominal hepatic and splenic angiosarcomas is essential. Surgery is the treatment of choice, and there is no current evidence on the management of cases with locoregional or distant involvement.

The genetic landscape of SMARCB1 alterations in SMARCB1-deficient spectrum of mesenchymal neoplasms

SMARCB1 biallelic inactivation resulting in SMARCB1/INI1 deficiency drives a wide range of malignancies, including many mesenchymal tumors. However, the specific types of SMARCB1 alterations and spectrum of cooperating mutations among various types of sarcomas has not been well investigated. We profiled SMARCB1 genetic alterations by targeted DNA sequencing and fluorescence in situ hybridization (FISH) in a large cohort of 118 soft tissue and bone tumors, including SMARCB1-deficient sarcomas (78, 66%): epithelioid sarcomas, epithelioid peripheral nerve sheath tumors, poorly differentiated chordomas, malignant rhabdoid tumors, and soft tissue myoepithelial tumors, as well as non-SMARCB1-deficient sarcomas (40, 34%) with various SMARCB1 genetic alterations (mutations, copy number alterations). SMARCB1 loss by immunohistochemistry was present in 94% SMARCB1 pathogenic cases. By combined sequencing and FISH assays, 80% of SMARCB1-deficient tumors harbored homozygous (biallelic) SMARCB1 loss, while 14% demonstrated heterozygous SMARCB1 loss-of-function (LOF) alterations, and 6% showed no demonstrable SMARCB1 alterations. FISH and sequencing were concordant in the ability to detect SMARCB1 loss in 48% of cases. Epithelioid sarcomas most commonly (75%) harbored homozygous deletions, while a subset showed focal intragenic deletions or LOF mutations (nonsense, frameshift). In contrast, most soft tissue myoepithelial tumors (83%) harbored SMARCB1 nonsense point mutations without copy number losses. Additionally, clinically significant, recurrent co-occurring genetic events were rare regardless of histotype. By sequencing, extended 22q copy number loss in genes flanking the SMARCB1 locus (22q11.23) occurred in one-third of epithelioid sarcomas and the majority of poorly differentiated chordomas. Poorly differentiated chordomas and soft tissue myoepithelial tumors showed significantly worse overall and disease-free survival compared to epithelioid sarcomas. Overall, SMARCB1 LOF alterations predominate and account for SMARCB1 protein loss in most cases: majority being biallelic but a subset were heterozygous. In contrast, SMARCB1 alterations of uncertain significance can be seen in diverse sarcomas types and does not indicate a SMARCB1-deficient entity.

What's the latest with investigational drugs for soft tissue sarcoma?

INTRODUCTION

Despite extensive research undertaken in the past 20-30 years, the treatment for soft tissue sarcoma (STS) has remained largely the same, with anthracycline-based chemotherapy remaining the first choice for treating advanced or metastatic STS.

AREAS COVERED

This review focuses on newly approved drugs for STS and current research directions, including recent results of late-phase trials in patients with STS. We cover several different histological subtypes, and we discuss the role of adoptive cell transfer (ACT) therapies for the treatment of synovial and myxoid/round cell (high-grade myxoid) liposarcoma, one of the most promising areas of treatment development to date. We searched clinicaltrials.gov and pubmed.ncbi.nih.gov, as well as recent year proceedings from the annual conferences of the American Society of Clinical Oncology (ASCO), European Society for Medical Oncology (ESMO), and Connective Tissue Oncology Society (CTOS).

EXPERT OPINION

Immune-oncology drugs (IOs) show promise in certain subtypes of STS, but it is recognized that PD-1/PD-L1 axis inhibition is not enough on its own. Better trial stratifications based on the molecular categorization of different subtypes of STS are needed, and more evidence suggests that 'one size fits all' treatment is no longer sustainable in this heterogeneous and aggressive group of tumors.

Epithelioid Vascular Lesions: The Differential Diagnosis and Approach in Cytology and Small Biopsies

Vascular neoplasms are rare tumors with a multitude of clinical presentations and behavior, which make accurate identification and subclassification challenging on limited small biopsies. Within the spectrum of these lesions, the ones with epithelioid morphology, such as epithelioid hemangioendothelioma and epithelioid angiosarcoma, are particularly challenging given the morphologic overlap with nonvascular lesions and the limited cells due to hemodilution on sampling. Herein, we review the differential diagnosis of epithelioid vascular neoplasms, with a focus on the cytomorphology, differential diagnoses, and ancillary studies that pathologists should be aware of when evaluating small biopsies and aspirates, including novel translocations, and associated monoclonal immunohistochemistry antibodies, that can help in the diagnosis of some of these tumors. Awareness of these morphologic and ancillary study findings in these rare tumors will hopefully allow pathologists to recognize and render-specific diagnoses on limited samples of these challenging lesions.

Epithelioid sarcoma and its outcome: a retrospective analysis from a tertiary care center in North India

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.

Prognostic nomogram in patients with epithelioid sarcoma: A SEER-based study

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.

Beyond SMARCB1 Loss: Recent Insights into the Pathobiology of Epithelioid Sarcoma

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.

Epithelioid Sarcoma Presenting in the Thumb of a Child

Epithelioid sarcoma (ES) is a high-grade, soft tissue tumor of mesenchymal origin that rarely occurs in children and is often misdiagnosed as a benign entity. We present the case of a 12-year-old girl with a delayed diagnosis of ES of the left thumb. Radiological examination showed possible calcinosis from inflammation or traumatic injury. However, histopathological and immunohistochemistry studies showed findings consistent with a diagnosis of ES. She was treated with amputation of the interphalangeal joint of the left thumb. This case highlights the clinical and pathologic correlation required for the appropriate diagnosis and treatment of patients with soft tissue masses.

Malignant rhabdoid tumor: Cyto-histologic correlation and immunohistochemical characterization of a rare pediatric malignancy and its differential diagnoses

Malignant rhabdoid tumor of the kidney (MRTK) is a rare aggressive pediatric renal tumor which can be diagnosed via fine-needle aspiration (FNA) cytology and core biopsy. The diagnosis of MRTK is challenging, and requires morphologic, immunohistochemical and clinical correlation to distinguish it from other entities. The differential diagnosis includes Wilms tumor, desmoplastic small round cell tumor, rhabdomyosarcoma, synovial sarcoma, renal medullary carcinoma, and epithelioid sarcoma. Here we describe a case of MRTK diagnosed on renal cytology and core biopsy with immunohistochemistry and follow by nephrectomy with gross and morphologic findings.

Epithelioid Sarcoma in the Median Nerve of the Hand: A Case Report

Epithelioid sarcoma of the peripheral nerves is extremely rare. We present a case concerning the median nerve of the right hand in a 35-year-old woman who was treated with radical resection, reconstructive surgery, and chemotherapy. After 2 years of follow-up, there is no evidence of local recurrence or metastatic dissemination.

Myoepithelioma-like tumors of the vulvar region: A case report and review of the literature

Myoepithelioma-like tumors of the vulvar region (MELTVR) is a kind of solid tumor newly recognized in recent years, which is characterized by mesenchymal tumors of adult female vulva. The histopathology is similar to myoepithelioma, but the immunohistochemical phenotype and genetic changes are different from myoepithelioma. It usually has clear boundary and partial capsule, mixed with two forms of cells (epithelioid and spindle), the cells are mild, the nucleoli are clear, mitoses are rare, some cases have myxoid differentiation. In this article, a case of MELTVR diagnosed in our hospital is discussed. The patient was a 43-year-old female who finds a neoplasm in the pubic tubercle 4 months ago. Local resection was performed. Pathological examination showed that the boundary of the tumor was clear with partial capsule. The cells were arranged in cords or nests, and partially infiltrated the surrounding adipocytes. The tumor cells had two morphologies, epithelioid or spindle shaped. The spindle type cells were dominant, with bright cytoplasm, obvious nucleoli, rare nuclear mitosis (about 1/10HPF), and no necrosis was observed. Immunohistochemically, the tumor cells were positive for vimentin, epithelial membrane antigen, estrogen receptor, progestogen receptor, calponin and were partially positive for cathepsin k. INI1/SMARCB1 expression was deficient. There was no recurrence or metastasis during the 8-month-long follow-up. The unique feature of this case was that the site of the disease was not the vulva, but in front of the pubic tubercle, there was no large amount of mucus production, and the cytoplasm of most tumor cells was transparent. Due to our limited knowledge of MELTVR, its pathogenesis and tissue origin are not clear. Clinicians should be aware of such potential patients.

Malignant Superficial Mesenchymal Tumors in Children

Malignant superficial mesenchymal tumors are a very diverse group of neoplasms with few clinical and radiological discriminatory factors. Hence, some of these cancers are rarely suspected based on clinical and radiological grounds, others may be easily misdiagnosed, and the histological analysis of a biopsy or resection is central in the diagnostic process. In children, the age at presentation is a major element of the differential diagnosis. Some tumors have a very distinct epidemiology, while others may be seen at any age. More recently, the advances in molecular biology have greatly improved the diagnosis of mesenchymal tumors and new entities are still being described. In the present review, we provide an overview of the diversity of malignant superficial mesenchymal tumors in children, including new and/or rare entities. We discuss the important diagnostic features, be they clinical, histological, or molecular. Special attention was given to the genetic features of these tumors, particularly when they were helpful for the diagnosis or treatment.

Extrapleural Pneumonectomy for Sarcoma of the Lung in a Pediatric Patient

Pediatric sarcomas are rare entities. Bone sarcomas and rhabdomyosarcoma are most common, whereas primary sarcoma of the lung is extremely uncommon. Pneumonectomy is only very infrequently performed in the pediatric population. We report on a 16-year-old girl with an undifferentiated high-grade pleomorphic sarcoma of the left lung. There was no comorbidity and no history of previous malignant disease. The huge tumor originated from the left lower lobe and had spread to the left pleura. As part of a multimodal approach, she underwent extrapleural pneumonectomy with en bloc resection of the pleura, lung, pericardium, and diaphragm.

Primary Adrenal Epithelioid Sarcoma in a Child: A Case Report with Literature Review

Introduction; Epithelioid sarcoma is a malignant mesenchymal neoplasm with evidence of epithelial differentiation. All the cases reported in the solid organs are of "proximal type" occurring in adults. We report a primary epithelioid sarcoma arising in the adrenal gland of a young male. Case report: An 11-year-old male patient presented with right loin pain. Imaging revealed a 10.8 × 10.8 × 13.5 cm complex cystic mass with obscured right adrenal gland. Clinical and radiological studies did not reveal metastases. Histologic features were those of proximal type epithelioid sarcoma with extensive central necrosis. Immunohistochemistry showed strong positivity for pancytokeratin, vimentin, and CD34. Nuclear expression of SMARCB1 (INI-1) protein was lost. Conclusion: Proximal type of epithelioid sarcoma can arise from solid organs such as the adrenal.

Primary adult sellar SMARCB1/INI1-deficient tumor represents a subtype of atypical teratoid/rhabdoid tumor

Loss of function in SMARCB1/INI1 has been observed in a group of malignancies collectively defined as SMARCB1/INI1-deficient neoplasms. Primary intracranial SMARCB1/INI1-deficient tumors in adults are extremely rare. We collected eight primary adult sellar SMARCB1/INI1-deficient tumors to study their clinicopathological and (epi)genetic characteristics. We performed a comprehensive assessment of the clinical, radiological, morphological and immunohistochemical features. FISH analysis for the SMARCB1 locus and target exome sequencing for 425 cancer relevant genes were performed. Furthermore, six bona fide proximal epithelioid sarcoma (PES), fourteen atypical teratoid/rhabdoid tumors (ATRT) in brain and five pediatric poorly differentiated chordomas (PDC) in the clivus were collected for comparative analysis of differential diagnostic maker expression and DNA methylation profile. The median age was 47.1 years, ranging from 26 to 73 years. On morphology, tumors were characterized by sheets of monomorphic larger epithelioid-like cells, in two cases with rhabdoid cells. "Stag-horn" vasculatures were observed in five cases. The loss of INI1 protein expression, co-expression of epithelial makers and mesenchymal markers were observed in all cases. CD34 expression was observed in six cases. Heterozygous deletion of SMARCB1/INI1 was confirmed using FISH in six cases. The results of target exome sequencing showed three patients harbored heterozygous point mutations in SMARCB1. The epigenetic features of the primary adult sellar SMARCB1/INI1-deficient tumors resembled the ATRT-MYC subgroup, but clustered apart from PES and PDC. Based on epigenetic characteristics, primary adult sellar SMARCB1/INI1-deficient tumors represent a subtype of ATRT with similar epigenetic characteristics of ATRT-MYC subgroup. Our findings suggest that DNA methylation profiling should be utilized for differential diagnosis for the majority of epithelioid sarcoma and (sellar) rhabdoid tumor.

Molecular targeted therapy for advanced or metastatic soft tissue sarcoma

Soft tissue sarcomas are a form of rare and heterogeneous neoplasms with high recurrence rate and mortality. Over the past decades, less progress has been achieved. Surgical management with or without adjuvant/neoadjuvant radiotherapy is still the first-line treatment for localized soft tissue sarcomas, and chemotherapy is the additional option for those with high-risk. However, not all patients with advanced or metastatic soft tissue sarcomas benefit from conventional chemotherapy, targeted therapy takes the most relevant role in the management of those resistant to or failed to conventional chemotherapy. Heterogeneous soft tissue sarcomas vary from biological behavior, genetic mutations, and clinical presentation with a low incidence, indicating the future direction of histotype-based even molecule-based personalized therapy. Furthermore, increasing preclinical studies were carried out to investigate the pathogenesis and potential therapeutic targets of soft tissue sarcomas and increasing new drugs have been developed in recent years, which had started opening new doors for clinical treatment for patients with advanced/metastatic soft tissue sarcomas. Here we sought to summarize the concise characteristics and advance in the targeted therapy for the most common subtypes of soft tissue sarcomas.

New FDA oncology small molecule drugs approvals in 2020: Mechanism of action and clinical applications

In 2020, fifty-three new drugs, including forty small-molecules (thirty-six new chemical entities and four new diagnostic agents) and thirteen biologic drugs were approved by the U.S. Food and Drug Administration (FDA). This year, small-molecules continue to play a role in innovative treatments representing around 75% of all drugs accepted by FDA. The dominant therapeutic area was oncology, accounting for twenty-three new approvals, including thirteen new chemical entities, four new diagnostic agents, and thirteen biologic drugs. Recognizing the importance of small-molecules on cancer treatment, this review aims to provide an overview regarding the clinical applications and mechanism of action of the thirteen new small-molecules (excluding new diagnostic agents) approved by FDA in 2020.

Epithelioid Sarcoma of the Peripheral Nerve: Clinicopathologic Series of Three Cases and Literature Review

OBJECTIVES

Epithelioid sarcoma (ES) rarely arises in the nerve. To increase our understanding of this unusual tumor originating in the nerve, we describe the features of three cases and review the literature.

METHODS

Clinical data, imaging, pathology, treatment, and follow-up are detailed. A systematic literature review was conducted.

RESULTS

Two patients were male and one female; the median age was 24 years. The patients had neurologic symptoms, and the tumors arose in large nerves and ranged from 2.4 to 5.8 cm. The tumors were avid on positron emission tomography-computed tomography and showed increased signal intensity on T2-weighted magnetic resonance imaging. Centered in the nerve, the tumors grew with an infiltrative pattern and encased the nerve fascicles. All were treated with wide resection, and adjuvant treatment included combinations of chemotherapy and radiation. One recurred, and the limb was amputated. Metastases were documented to lymph nodes, lung, pleura, and skin. One patient died of disease after 54 months. Literature review including our cases showed that tumors stained with pancytokeratin (9/9), EMA (4/4), and CD34 (7/7); there was loss of INI1 in all six cases tested.

CONCLUSIONS

ES rarely arises in the peripheral nerve, and its infiltrative nature often requires morbid surgery. The differential includes a variety of benign and malignant epithelioid neoplasms.