Spindle Cell Sarcoma

The so far absolute predilection of this fusion for renal tumors, coupled with the absence of reports of other GLI1 fusions in tumors of the kidney, might indicate the potential existence of a distinct renal subtype with morphological features similar to other GLI1-altered tumors. All four reported cases had an uneventful follow-up which, together with their low-grade morphological features, suggests that these tumors might have a favorable prognosis.

One patient received adjuvant radiotherapy, whereas the other received ifosfamide and doxorubicin-based therapy. There was a suboptimal response to chemotherapy in both patients.This study highlights the clinicopathological features of two rare and emerging sarcomas. It further emphasizes the value of high-throughput molecular testing, such as next-generation sequencing in the undifferentiated epithelioid, and spindle-cell sarcomas to identify the prognostic subtypes and differentiate these neoplasms from their histopathological mimics.

Pathological morphology and immunohistochemical analyses deepen our understanding of the pathological features of TSC and provide a diagnostic reference for clinicians who will encounter such cases in the future.

NTRK-rearranged spindle cell tumours' definitive diagnosis enables targeted therapy. Fine-needle aspiration cytology, being minimally invasive, offers the potential for earlier and more definitive diagnoses, thereby improving patient treatment options.

Herein we describe a patient with secretory carcinoma showing transdifferentiation into metaplastic carcinoma (spindle cell and squamous cell carcinoma) at the metastatic site following treatment. Identification of these morphologic shifts is crucial for accurate classification and identification of potential resistant mechanisms.

Following 1 month of entrectinib treatment, the patient experienced considerable tumor shrinkage and symptomatic improvement. For bone-derived NTRK-rearranged spindle cell sarcomas, entrectinib shows promising therapeutic efficacy and should be considered a preferred treatment option.

In our patient with SGC, NGS revealed a GPHN-ALK variant that allowed off-label treatment with alectinib, with a remarkable response in primary and metastatic foci. Similarly, the use of NGS in a cutaneous neoplasm in which no definitive diagnosis could be reached by pathology and which had progressed through standard of care treatment elucidated a PIK3CA mutation in which alpelisib was added and ultimately halted POD. Here, we discuss the use of NGS, future projections, and our recommendations.

The patient was referred for palliative chemotherapy due to the tumor's aggressive nature. This case highlights the clinical presentation and diagnostic challenges of PB with endobronchial invasion.

No abstract available

Since BRAF activation occurs in BRAF fusion gene tumors and BRAF mutations, they could share a similar mechanism in tumorigenesis. This case suggests the further expansion of kinase-related spindle cell tumors.

P3, N=325, Active, not recruiting, National Cancer Institute (NCI) | Trial completion date: Oct 2024 --> Oct 2025

Primary mesenchymal tumors and neuroendocrine neoplasms were excluded because immunohistochemistry was negative for anaplastic lymphoma kinase (ALK), smooth muscle actin (SMA), desmin, CD34, signal transducer and activator of transcription 6 (STAT6), S100, HMB45, CD117, discovered on GIST-1 (DOG1), CD56, progesterone, and synaptophysin...This study highlights the clinical characteristics, diagnosis, and treatment of rare pancreatic cancer, emphasizing the importance of molecular testing and histopathological biomarkers in personalizing treatment. It also provides insights into promising therapeutic approaches for similar cases with an unusual presentation.

SFT is a distinctive spindle cell tumor of fibroblastic differentiation, characterized by prominent branching staghorn-like vessels and a specific NAB2::STAT6 gene fusion. We herein contribute with a central SFT of the mandible with recurrent behavior and radiographic appearance suggesting malignancy.

This case presenting a distinctive pattern of dedifferentiation is, to our knowledge, the first documented case of low-grade leiomyosarcoma occurring in parosteal osteosarcoma. As it enhances the clinical understanding by broadening the range of dedifferentiated components identified in parosteal osteosarcoma and highlights the diagnostic difficulties associated with these uncommon bone tumors.

Immunohistochemically, the tumors diffusely expressed S100 and CD34, with strong ALK-D5F3 positivity, confirmed by ALK gene rearrangement. These findings further expand the clinical and pathological spectrum of ALK-rearranged neoplasms and highlight the need for continued research on their biological behavior and classification.

We present an intriguing case report of a 5-year-old boy diagnosed with a moderately cellular mandibular spindle cell tumor exhibiting BCOR-ITD rearrangement which was initially misdiagnosed as an odontogenic fibromyxoma. This case report illustrates the histological and immunophenotypic findings of BCOR-ITD rearranged sarcoma, requiring a comprehensive immunohistochemical panel and additional molecular tests for accurate diagnosis.

P3, N=118, Recruiting, Children's Oncology Group | Active, not recruiting --> Recruiting

Most of the tumors are spindle cell tumors, with myogenic and neurogenic histological characteristics. Although uveal leiomyoma is more frequently found in women of reproductive age, it shows no significant correlation with estrogen and progestational hormones.

Malignant tumors should be included in the differential diagnosis of cardiac masses. Prompt diagnosis and complete surgical resection are essential for improving patient outcomes and reducing the risk of recurrence.

These findings further substantiate the hypothesis that SAMS and epithelioid FH may represent a morphologic and genetic spectrum. The differential diagnosis, clinical follow up, and the molecular genetic findings will be discussed.

There was no evidence of disease progression at 4 months. This is the first case of a soft tissue tumor harboring a PAK2::RAF1 fusion with histological features in keeping with previous cases of RAF1 and other kinase fusion soft tissue tumors.

Diffuse strong nuclear cyclin D1 expression was seen in both cases, and conversely, strong cyclin D1 staining was only seen in 5.4% (4/74) of well-differentiated neuroendocrine tumors tested. These 2 GI tract neoplasms highlight a widened spectrum of GLI1-rearranged tumors, now including monophasic epithelial neoplasms with diffuse keratin expression.

SS18-SSX-positive staining may be used as a surrogate for FISH assay in a resource-limited setting where molecular assay is not available. Furthermore, IHC has a fairly shorter turn-around-time, is less complex, and of low cost.

No abstract available

The present study found that sentinel lymph node biopsy was feasible in appropriate patients, and that chemotherapy regimens incorporating anthracycline-class drugs did not appear to improve OS. Anti-angiogenic therapy holds promise as a potentially effective treatment approach for MBC, and the optimization of systemic treatment strategies should be a priority in the management of these patients.

We also detected upregulation of the expression of PAX3, MAML3, and 11 known genes involved in neural and myogenic differentiation relevant to the BSNS phenotype. Hence, using WGTS in combination with conventional pathological diagnosis can contribute to a definitive diagnosis of rare cancers, including BSNS, by detecting chromosomal rearrangements or diagnostic markers.

The patient in case 2 had no other known tumors at the time of diagnosis, but no follow-up is available. We believe the reported cases represent a hitherto unrecognized variant of "NTRK-rearranged spindle cell neoplasms" of the uterine cervix with novel EGFR mutations.

This case stands out due to its unique presentation, characterized by a predominantly spindle cell morphology with certain epithelioid features. It is imperative to recognize this condition for an accurate diagnosis, emphasizing the spindle cell-type MPNST and highlighting its exceptionally poor prognosis.

Given the often non-specific histology and immunophenotype of mesenchymal nonmeningothelial tumors of uncertain differentiation, molecular techniques have become indispensable for accurate diagnosis. This review provides a comprehensive overview of primary mesenchymal non-meningothelial CNS tumors, including their clinical, radiological, histopathological, and molecular characteristics and treatment strategies.ABBREVIATIONS: ALK: Anaplastic lymphoma kinase; ATF1: activating transcriptase factor-1; CREB: cAMP response element-binding protein; CREM: cAMP response element modulator; CIC: Capicua transcriptional receptor; EWSR1: Ewing sarcoma RNA binding protein; FUS: fused in sarcoma; NAB2: nerve growth factor-inducible protein A binding protein 2; STAT6: signal transducer and activator of transcription 6; WHO: World Health Organization WHO CNS5: World Health Organization Classification of Tumors of the Central Nervous System, fifth edition.

Histopathological examination showed an irregular arrangement of spindle cells, and immunohistochemical staining was positive for CD34 and STAT6, confirming an SFT diagnosis with low metastatic risk. Robotic surgery effectively managed this tumor.

This review provides an overview of the current knowledge on the clinicoradiological features, pathogenesis, histopathology, and treatment of ASCPLT. In addition, we will discuss the differential diagnosis of this new entity.

SAMS is on a morphologic and molecular genetic spectrum with EFH, with a similar body site distribution, frequent clinical presentation as an exophytic skin tumor, and invariably benign outcomes; we conclude that SAMS should be considered a histologic variant of EFH. Some morphologically typical examples harbor alternate RET and NTRK3 fusions, such that SAMS is not an appropriate designation for this morphologic class; instead, to highlight the clinicopathologic similarities to EFH, we propose the diagnostic term "myxoid spindle cell variant of epithelioid fibrous histiocytoma."

Here, we have provided a review of selected emerging mesenchymal neoplasms, which of these neoplasms will meet the threshold to be 'new entities' remains to be determined.

Cross-striations were not evident with H&E or phosphotungstic acid-hematoxylin stains. Markedly pleomorphic neoplastic cells, multinucleate cells, and lack of cross-striations suggested the subclassification of pleomorphic RMS.

Identifying patients with NTRK gene fusions is crucial, as they could benefit from targeted therapy using TRK inhibitors. This requires a detailed description of emerging entities like NTRK-RSCNs because testing for NTRK rearrangement is not routinely performed. In two cases, we report a spectrum of histological grades, including a high-grade phenotype.

In this particular case, the immunohistochemical and molecular results support a diagnosis of a fibroblastic/myofibroblastic tumour of uncertain behaviour. Notably, there have been no reported cases in the literature of a soft tissue tumour harboring FGFR1::TACC1 fusion as a primary occurrence in this anatomical location. The patient remains in good health without any evidence of disease recurrence at the 5-month follow-up post-surgical intervention.

Spindle cells were positive for CD34, Factor XIIIa and vimentin. To our knowledge, this is the first case of intestinal perforation secondary to a calcifying fibrous tumor described in the literature.

The tumor had a specific NAB2-STAT6 fusion.Solitary fibrous tumors rarely occur in the thyroid gland and are described as both primary and secondary manifestations. The diagnosis, prognosis assessment and treatment decision are carried out analogously to SFT of other localizations.

These specifically include three novel cutaneous mesenchymal tumors with melanocytic differentiation, and rearrangements of the CRTC1::TRIM11, ACTIN::MITF, and MITF::CREM genes as well as EWSR1::SMAD3-rearranged fibroblastic tumors, superficial CD34-positive fibroblastic tumors, and NTRK-rearranged spindle cell neoplasms. Some of the other most important changes will be briefly mentioned as well.

Our case highlights the potential of a NONO::TFE3 cutaneous epithelioid and spindle cell tumor to recur after a prolonged disease-free interval without evidence of high-grade transformation or distant metastasis. Our findings support its classification as a cutaneous mesenchymal neoplasm of intermediate malignancy.

These findings were consistent with those of SAMS. This case suggests that SAMS should be considered when identifying large nonspecific masses during clinical and imaging evaluation.

P3, N=205, Recruiting, Children's Oncology Group | Trial completion date: Dec 2030 --> Jun 2030 | Trial primary completion date: Dec 2030 --> Jun 2030