Outcomes of children with clear cell sarcoma of kidney following NWTS strategies in Shanghai China (2003-2021).

BACKGROUND: Although clear cell sarcoma of kidney (CCSK) is rare, it is the second most common renal tumor in children after Wilms' tumor. NWTS and SIOP are two major groups which had made tremendous efforts on renal tumors, but the strategies are different, for NWTS follows the upfront surgery principle providing definite pathology and the SIOP follows the upfront chemotherapy principle, each has its own advantages. Here we aimed to evaluate the outcomes of CCSK in China following NWTS strategies to analyze the prognostic factors. METHODS: For this multicenter retrospective study, a total of 54 patients were enrolled from three children's hospitals, between April 2003 and December 2021. Treatment comprised upfront radical nephrectomy, followed by radiotherapy and intensive chemotherapy. Clinical records were regularly updated. Prognostic factors and survival rates were evaluated. RESULTS: The 54 enrolled patients had a median age of 37 months (range, 4 months to 11.4 years). The stage distribution was 16% stage I (n = 9), 30% stage II (n = 16), 39% stage III (n = 21), and 15% stage IV (n = 8). Among stage IV, metastasis sites included the lung (n = 6), bone (n = 1), and intra-orbital/cervical lymph node (n = 1). After a median follow-up of 5.6 years, the 5-year event-free survival (EFS) was 82.4±5.4%, and overall survival was 88.1±4.6%. The EFS was 100% for stage I, 93.8 ±6.1% for stage II, 71.1±10.0% for stage III, and 68.6±18.6% for stage IV. Univariate analysis revealed that staging (III/IV), tumor rupture, and inferior vena cava tumor thrombus were inferior prognostic factors. Multivariate analysis revealed that tumor rupture was independent poor prognostic factor (P = 0.01, HR 5.9). Among relapsed patients, relapse occurred a median of 11 months after diagnosis (range, 4-41 months), and 50% (4/8) achieved a second complete remission after multiple treatment. None of the six lung metastasis patients received lung RT, only one patient developed a relapse and was salvaged by RT after relapse. CONCLUSIONS: Tumor rupture was independent poor prognostic factor. Upfront surgery of NWTS strategies can make a definite pathology diagnosis, but how to reduce tumor rupture during surgery is important especially in developing countries. The outcomes of patients with stage I-III CCSK in China were comparable to findings in other developed countries. Better outcomes were achieved in stage IV CCSK by using an intensive chemotherapy regimen including carboplatin, which require further confirmation by AREN0321. Lung RT may be safely omitted in selected patients who achieve a compete radiographic response after 6 weeks of systemic treatment (including surgery). Treatment should be encouraged even in CCSK cases with metastasis and relapse.

Navigating diagnostic challenges-distinguishing malignant melanoma and clear cell sarcoma of soft tissues: a case report and review of the literature.

BACKGROUND: Within the spectrum of melanocytic-differentiated tumors, the challenge faced by pathologists is discerning accurate diagnoses, with clear cell sarcoma of soft tissues standing out as a rare and aggressive neoplasm originating from the neural crest. Accounting for 1% of all soft tissue sarcomas, clear cell sarcoma of soft tissues poses diagnostic complexities, often misidentified owing to its phenotypic resemblance to malignant melanoma. This chapter delves into the intricacies of clear cell sarcoma of soft tissues, its epidemiology, characteristic manifestations, and the imperative need for a comprehensive diagnostic approach involving immunohistochemical and molecular analyses. CASE PRESENTATION: A compelling case unfolds as a 25-year-old male from Morocco, initially misdiagnosed with malignant melanoma, experiences tumor recurrence on the second toe. With no history of trauma or familial neoplasia, the patient's clinical journey is explored, emphasizing the importance of detailed clinical examinations and radiological assessments. The chapter elucidates the histopathological findings, immunohistochemical spectrum, and the correlation between clinical parameters and diagnostic inference, ultimately leading to metatarsal amputation. This clinical vignette highlights the multidimensional diagnostic process in soft tissue neoplasms, emphasizing the synergistic role of clinical, radiological, and histopathological insights. CONCLUSION: The diagnostic challenges inherent in melanocytic-differentiated tumors, exemplified by the rarity of soft tissue clear cell sarcoma, underscore the essential role of an integrated diagnostic approach. This concluding chapter emphasizes the perpetual collaboration required across pathology, clinical medicine, and radiology for nuanced diagnostic precision and tailored therapeutic strategies. The rarity of these soft tissue malignancies necessitates ongoing interdisciplinary engagement, ensuring the optimization of prognosis and treatment modalities through a comprehensive understanding of the diagnostic intricacies presented by clear cell sarcoma of soft tissues.

A Comparison of Clear Cell Sarcoma to Jaw and Salivary Tumors Bearing EWS Fusions.

OBJECTIVE: To review tumors identified as "clear cell sarcoma" in order to determine similarities to the rare EWS fusion positive jaw and salivary gland tumors clear cell odontogenic carcinoma (CCOC) and clear cell carcinoma of the salivary gland (CCC). METHODS: PubMed was used to collect all reports of clear cell sarcoma (CCS). Search parameters were "clear cell sarcoma" and "CCS." References in the publications were screened and cross-referenced. Data extracted included demographic characteristics, presenting signs and symptoms, radiographic findings, histological and immunohistochemical features and known molecular/genetic aberrations. RESULTS: Clear cell sarcoma has several similarities to CCOC and CCC. All three tumor types have similar histologic appearances including the presence of clear cells, as well as similar genetic profiles in that all harbor an EWSR1-CREB family fusions. Additionally, these tumors appear in soft tissue as well as bone, and can have a prolonged clinical course. CCS can appear anywhere in the body, including the head and neck region. All three tumors appear to have a predilection to women, although CCS may have a slight younger age of onset as compared to CCOC and CCC (3rd vs 5th decade of life, respectively). CONCLUSION: Gaining a better understanding of the similarities and differences between these three tumors may lead to a better understanding of each one.

Tumor neuroectodérmico maligno del tracto gastrointestinal: a propósito de un caso / Malignant neuroectodermal tumor of the gastrointestinal tract: case report

El tumor neuroectodérmico maligno del tracto gastrointestinal es una neoplasia rara con pocos casos reportados en la literatura, especialmente en América Latina. Descrito por primera vez en 2003, se trata de una entidad sin tratamiento estandarizado y de pobre pronóstico. Se presenta el caso de una paciente de 22 años de edad que acude a la consulta por dolor abdominal, anemia y masa abdominal palpable. Luego de estudios pertinentes se decide la conducta resectiva y el posterior tratamiento oncológico. (AU)

Malignant gastrointestinal neuroectodermal tumor (GNET), formerly known as clear cell sarcoma of the gastrointestinal tract, is an extremely rare tumor of mesenchymal origin, which presents great microscopic and molecular similarity to clear cell sarcoma found in other parts of the body, such as tendons and aponeurosis. It is characterized by its rapid evolution, high recurrence rate and frequent diagnosis as metastatic disease.1,2 (AU)

Treatment and outcomes of clear cell sarcoma of the kidney: A report from the Children's Oncology Group studies AREN0321 and AREN03B2.

BACKGROUND: On the fifth National Wilms Tumor Study, treatment for clear cell sarcoma of the kidney (CCSK) included combined vincristine, doxorubicin, cyclophosphamide, and etoposide (regimen I) plus radiation therapy (RT), yielding 5-year event-free survival (EFS) rates of 100%, 88%, 73%, and 29% for patients who had with stage I, II, III, and IV disease, respectively. In the Children's Oncology Group study AREN0321 of risk-adapted therapy, RT was omitted for stage I disease if lymph nodes were sampled, and carboplatin was added for stage IV disease (regimen UH-1). Patients who had stage II/III disease received regimen I with RT. METHODS: Four-year EFS was analyzed for patients enrolled on AREN0321 and on those enrolled on AREN03B2 who received AREN0321 stage-appropriate chemotherapy. RESULTS: Eighty-two patients with CCSK enrolled on AREN0321, 50 enrolled on AREN03B2 only. The 4-year EFS rate was 82.7% (95% confidence interval [CI], 74.8%-91.4%) for AREN0321 and 89.6% (95% CI, 81.3%-98.7%) for AREN03B2 only (p = .28). When combining studies, the 4-year EFS rates for patients who had stage I (n = 10), II (n = 47), III (n = 65), and IV (n = 10) disease were 90% (95% CI, 73.2%-100.0%), 93.4% (95% CI, 86.4%-100.0%), 82.8% (95% CI, 74.1%-92.6%), and 58.3% (95% CI, 34%-100.0%), respectively. There were no local recurrences among seven patients with stage I disease who were treated without RT. One stage I recurrence occurred in the brain, which was the most common site of relapse overall. Among patients with local stage III tumors, neither initial procedure type, margin status, nor lymph node involvement were prognostic. CONCLUSIONS: Patients with stage I CCSK had excellent outcomes without local recurrences when treated without RT. Patients with stage IV disease appeared to benefit from a carboplatin-containing regimen, although their outcomes remained unsatisfactory. Further research is needed to improve outcomes for patients with advanced-stage disease (ClinicalTrials.gov identifiers NCT00335556 and NCT00898365).

A solitary scalp mass as the presenting feature of clear cell sarcoma of the kidney in a pediatric patient.

Clear cell sarcoma of the kidney is a rare renal malignancy, accounting for 2%-4% of all pediatric renal tumors. In this case report, we describe a 9-year-old boy with an asymptomatic, solitary mass on the scalp, ultimately found to be metastatic clear cell sarcoma of the kidney. This report reviews indications for imaging scalp masses to facilitate making an accurate diagnosis and treatment planning.

Small Intestine Gastrointestinal Clear Cell Sarcoma: A Case Report and Review of the Literature.

Gastrointestinal clear cell sarcoma (GICCS)/malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare form of cancer with aggressive clinical behavior. It has distinct pathological, immunohistochemical, ultrastructural, and molecular features. Herein, we present the case of a 20-year-old woman with no notable medical history who presented to the outpatient department with complaints of abdominal pain and vomiting. Symptoms had been evolving for 3 months. The physical examination revealed slight abdominal tenderness and melena. Biological investigations revealed iron-deficiency anemia. The upper and lower endoscopies showed no abnormalities. Magnetic resonance enterography revealed small bowel wall thickening of 15 mm × 2 mm. Exploratory laparotomy revealed an ileal mass with mesenteric lymphadenopathy. A wide resection of the mass was then performed. The final pathological report confirmed the diagnosis of small bowel GICCS/GNET. After 11 months of follow-up, the patient presented with mesenteric lymph node metastases.

MED15::ATF1-Rearranged Tumor: A Novel Cutaneous Tumor With Melanocytic Differentiation.

We recently described novel dermal tumors with melanocytic differentiation and morphologic and biological similarities to cutaneous clear cell sarcoma, including CRTC1::TRIM11 cutaneous tumor, and clear cell tumors with melanocytic differentiation and either ACTIN::MITF or MITF::CREM. Here, we describe a series of 3 patients presenting with tumors reminiscent of CRTC1::TRIM11 cutaneous tumor, found to demonstrate a novel MED15::ATF1 fusion. All 3 patients were children (5-16 years old). Primary excision of case 1 showed a circumscribed wedge-shaped silhouette with peripheral intercalation into collagen fibers and scattered lymphoid aggregates. All 3 tumors abutted the epidermis; one showed a junctional component. Tumors were highly cellular and comprised of monomorphic, oval-to-round epithelioid cells arranged in vague nests and short fascicles in variably fibrotic stroma. Mitotic rate was high (hotspot 6-12/mm2), without atypical mitoses. Necrosis was focally present in case 3. All cases showed strong, diffuse nuclear staining for SOX10 and MITF (2/2) but showed variable expression for S100 protein (1/3) and other melanocytic markers-Melan-A (focal in 2/3), HMB45 (focal in 1/3), and Pan-Melanoma (patchy in 1/1). Whole-exome RNA sequencing demonstrated a MED15::ATF1 fusion without any other notable alterations. Cases 1 and 2 were completely excised without recurrence (12 months). Case 3 developed a grossly apparent regional lymph node spread shortly after primary biopsy. The patient was treated with wide excision, radiation, cervical lymph node dissection (4/46 with >75% lymph node replacement), and neoadjuvant and adjuvant nivolumab (alive without disease at cycle 11). This series is presented to aid in future diagnosis of this novel dermal tumor with melanocytic differentiation and emphasize the potential for aggressive biologic behavior, which should be considered in patient management planning.

Brain metastases with unusual MRI features in an infant with relapsed clear cell sarcoma of the kidney: A case report.

Clear cell sarcoma of the kidney (CCSK) is a rare primary renal tumor in children. It is known for its propensity to metastasize to bones and lungs at initial diagnosis. Distant metastatic relapses occur in about 15-16% of the patients, with the brain being the most frequent site of relapse. Imaging features of brain metastases from CCSK have only been reported in a few cases and most reports lack a detailed description of the imaging findings. We present brain magnetic resonance imaging (MRI) findings in an infant with relapsed CCSK who developed multiple parenchymal metastases with concentric signal alterations and no tumor-associated edema.

Clear cell sarcoma of kidney: A mimicker of Wilms' tumor.

The differential diagnosis for an abdominal mass in a 2-year-old child is broad and includes lesions of renal, hepatic, gastrointestinal, adrenal, and lymphatic origins. Of these, Wilms' tumor and neuroblastoma are the most common tumors, where Wilms' tumor represents about 92% of renal masses in children. Non-Wilms' renal tumors, rhabdoid tumors, and clear cell sarcoma of the kidney (CCSK) are uncommon. CCSK constitutes approximately 3% of all malignant renal tumors in childhood. In this report, we present a child presenting with a huge renal mass consistent with Wilms' tumor on computed tomography and initial biopsy. However, the final pathologic diagnosis after resection revealed CCSK.

Clear cell sarcoma in the post-molar area: Report of an ultra-rare case and literature review of oral clear cell sarcoma.

BACKGROUND: Clear cell sarcoma of soft tissue is an exceptionally rare sarcoma. It is even rarer in the oral cavity. To our knowledge, this case is the first reported clear cell sarcoma involving the post-molar area. Pathologically, clear cell sarcoma has low mitotic activity, rare nuclear pleomorphism, and necrosis. Its biological behavior is often underestimated by morphology. It is a highly aggressive tumor. CASE REPORT: A 39-year-old female presented with an asymptomatic mass in the post-molar area. It was mistaken for a benign or low-grade malignant tumor based on frozen incisional biopsy samples. The surgical resection sample was tested by NGS, which detected a rare EWSR1::CREB1 in clear cell sarcoma. The final diagnosis was made by combining morphological, immunohistochemical, and molecular test results. The patient did not receive any adjuvant therapy after surgery and no recurrence of the disease was detected at 8 months of follow-up. CONCLUSION: The study highlights that mild histological manifestation in the oral cavity should be considered the possibility of CCS affecting young patients. Careful histological investigation, sufficient immunohistochemical staining, and molecular tests are essential to the diagnosis.

Navigating through the diagnostic minefield of clear cell sarcoma of soft tissue: Lessons from a challenging case with literature review.

Clear cell sarcoma of soft tissue (CCSST) is a rare soft tissue sarcoma occurring in young adults with a predilection for deep soft tissues of the distal extremities. Its overlapping morphology and immunohistochemical profile pose a diagnostic challenge. Herein, we present a rare case of CCSST with a unique immunohistochemical profile arising in an uncommon location. A 36-year-old male presented with a progressively increasing painful swelling in the left supraclavicular region for the last 2 months. Positron emission tomography showed FDG-avid lesions in the left supraclavicular and scapular regions. Fine needle aspiration cytology (FNAC) followed by core needle biopsy was performed. The cytology smears showed predominantly discohesive sheets of polygonal tumor cells with prominent macronucleoli in a vacuolated background. On immunocytochemistry, tumor cells showed positivity for vimentin, HMB45, and S100, confirming the diagnosis of CCSST. Histopathological examination showed sheets of similar tumor cells that were positive for vimentin, HMB45, melan A, CD38, and CD138, representing a potential diagnostic pitfall in the index case. The index report, besides highlighting the characteristic pathologic features of CCSST and its mimics, is unique due to the diffuse positivity of the tumor cells for CD38 and CD138. It is imperative to be aware of this diagnostic pitfall as it may muddle the diagnosis of CCSST.

The current management of clear cell sarcoma.

Clear cell sarcoma (CCS) is a rare melanocytic soft tissue sarcoma with a high propensity for lymphatic metastasis and poor prognosis. It is characterized by the translocation of t (12;22), resulting in the rearrangement of the EWSR1 gene and overexpression of MET. Despite improvements in the diagnosis and treatment of soft tissue sarcomas, the management of CCSs remains challenging owing to their rarity, unique biological behaviour and limited understanding of their molecular pathogenesis. The standard treatment for localized CCSs is surgical excision with negative margins. However, there is an ongoing debate regarding the role of adjuvant chemotherapy, radiotherapy and lymphadenectomy in the management of this disease. CCSs are usually resistant to conventional chemotherapy. Targeted therapies, such as sunitinib and MET inhibitors, may provide promising results. Immunotherapy, particularly immune checkpoint inhibitors, is currently under investigation as a potential treatment option for CCSs. Further research is needed to better understand the biology of CCSs and develop effective therapeutic strategies. The purpose of this review is to provide a comprehensive overview of current knowledge and advances in the diagnosis and treatment of CCSs.

Extraenteric Malignant Gastrointestinal Neuroectodermal Tumor-A Clinicopathologic and Molecular Genetic Study of 11 Cases.

Malignant gastrointestinal neuroectodermal tumors (MGNETs), also known as "gastrointestinal clear cell sarcoma-like tumors", are very rare, aggressive sarcomas characterized by enteric location, distinctive pathologic features, and EWSR1/FUS::ATF1/CREB1 fusions. Despite identical genetics, the clinicopathologic features of MGNET are otherwise quite different from those of clear cell sarcoma of soft parts. Only exceptional extraenteric MGNET (E-MGNET) has been reported. We report a series of 11 E-MGNETs, the largest to date. Cases diagnosed with MGNET and occurring in nonintestinal locations were retrieved. A clinical follow-up was obtained. The tumors occurred in 3 men and 8 women (range, 14-70 years of age; median, 33 years) and involved the soft tissues of the neck (3), shoulder (1), buttock (2), orbit (1), tongue/parapharyngeal space (1), urinary bladder (1), and falciform ligament/liver (1). Tumors showed morphologic features of enteric MGNET (small, relatively uniform, round to ovoid cells with round, regular nuclei containing small nucleoli growing in multinodular and vaguely lobular patterns, with solid, pseudoalveolar, and pseudopapillary architecture). Immunohistochemical results were S100 protein (11/11), SOX10 (11/11), synaptophysin (3/10), CD56 (7/9), CD117 (3/9), DOG1 (0/4), ALK (4/8), chromogranin A (0/10), HMB-45 (0/11), Melan-A (0/11), tyrosinase (0/4), and MiTF (0/11). Next-generation sequencing results were EWSR1::ATF1 (7 cases), EWSR1::CREB1 (3 cases), and EWSR1::PBX1 (1 case). The EWSR1::PBX1-positive tumor was similar to other cases, including osteoclast-like giant cells, and negative for myoepithelial markers. A clinical follow-up (range, 10-70 months; median, 34 months) showed 4 patients dead of disease (10.5, 12, 25, and 64 months after diagnosis), 1 patient alive with extensive metastases (43 months after diagnosis), 1 patient alive with persistent local disease (11 months after diagnosis), and 4 alive without disease (10, 47, 53, and 70 months after diagnosis). One case is too recent for the follow-up. The clinicopathologic and molecular genetic features of rare E-MGNET are essentially identical to those occurring in intestinal locations. Otherwise, typical E-MGNET may harbor EWSR1::PBX1, a finding previously unreported in this tumor type. As in enteric locations, the behavior of E-MGNET is aggressive, with metastases and/or death from disease in at least 50% of patients. E-MGNET should be distinguished from clear cell sarcoma of soft parts and other tumors with similar fusions. ALK expression appears to be a common feature of tumors harboring EWSR1/FUS::ATF1/CREB1 fusion but is unlikely to predict the therapeutic response to ALK inhibition. Future advances in our understanding of these unusual tumors will hopefully lead to improved nomenclature.

Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma.

BACKGROUND: Systemic therapy for metastatic clear cell sarcoma (CCS) bearing EWSR1-CREB1/ATF1 fusions remains an unmet clinical need in children, adolescents, and young adults. METHODS: To identify key signaling pathway vulnerabilities in CCS, a multi-pronged approach was taken: (i) genomic and transcriptomic landscape analysis, (ii) integrated chemical biology interrogations, (iii) development of CREB1/ATF1 inhibitors, and (iv) antibody-drug conjugate testing (ADC). The first approach encompassed DNA exome and RNA deep sequencing of the largest human CCS cohort yet reported consisting of 47 patient tumor samples and 8 cell lines. RESULTS: Sequencing revealed recurrent mutations in cell cycle checkpoint, DNA double-strand break repair or DNA mismatch repair genes, with a correspondingly low to intermediate tumor mutational burden. DNA multi-copy gains with corresponding high RNA expression were observed in CCS tumor subsets. CCS cell lines responded to the HER3 ADC patritumab deruxtecan in a dose-dependent manner in vitro, with impaired long term cell viability. CONCLUSION: These studies of the genomic, transcriptomic and chemical biology landscape represent a resource 'atlas' for the field of CCS investigation and drug development. CHK inhibitors are identified as having potential relevance, CREB1 inhibitors non-dependence of CCS on CREB1 activity was established, and the potential utility of HER3 ADC being used in CCS is found.