Chronic myeloid leukaemia with soft tissue mass formed by mature granulocytes.

Extramedullary lesions in patients with chronic myeloid leukaemia (CML) suggest progression to the blast phase because such lesions generally consist of immature granulocytes. We here report a case of an extramedullary mass formed by mature granulocytes during the chronic phase of CML. A 60-year-old woman who had discontinued treatment for CML with dasatinib of her own accord several years ago presented to our hospital with a complaint of right thigh pain. She had a mass on her right leg, which was located on her right thigh and was elastic, soft and fist-sized. Blood tests and the bone marrow findings were compatible with the chronic phase of CML, and a CT-guided needle biopsy showed an infiltrate containing numerous mature neutrophils and foam cells. The mass disappeared with dasatinib alone, without antibacterial agents or drainage.Although the detailed pathogenesis of mass formation with mature granulocytes in the chronic phase of CML has not been elucidated, the clinical course of the current case highlights the importance of prompt biopsy, pathological examination and the early initiation of appropriate treatment.

CIC::NUTM1 sarcomas occurred in soft tissues of upper limbs : a rare case report and literature review.

BACKGROUND: CIC-rearranged sarcomas (CRS) represent a new entity of undifferentiated small round cell sarcoma belonging to the Ewing-like sarcomas family. CRS are the most common type. Fusion partners for the CIC gene include DUX4, FOXO4, and the recently recognizedNUTM1. Rare cases of CIC::NUTM1 sarcoma in pediatric patients have recently been reported in brain, kidney, bone, and soft tissues. However, such cases have not been identified in the soft tissues of the limbs. CASE PRESENTATION: We reported a case of CIC::NUTM1 sarcoma located in the right upper limb of an 18-year-old man. The tumor displayed morphologic features typical of CIC::DUX4 sarcomas, with small- to medium-sized round cells, a lobular pattern, focal spindling, myxoid stroma, and patchy necrosis. The tumor diffusely expressed NUTM1, was positive for WT1cter at weak to moderate intensity, and was focally positive for CD99, while it was negative for keratins, EMA, P40, MyoD1, myogenin, NKX2.2, BCOR, and pan-TRK. Fluorescence in situ hybridization analyses revealed cleavage of the CIC and NUTM1 genes. CONCLUSION: CIC::NUTM1 sarcomas represent a novel molecular variant of CRS with a preference for the central nervous system and younger pediatric persons. Its morphology and phenotype may be mistaken for NUT carcinomas, and the behavior is more progressive than other forms of CRS. For this rare and newly discovered gene fusion variant, it is necessary to integrate molecular and immunohistochemical findings with morphologic features in the diagnosis of undifferentiated neoplasms.

Calcifying Spindle Cell Soft Tissue Tumor With SOX10::PLAG1 Fusion: A Case Report of a Morphologically Distinctive and Potentially Novel Soft Tissue Tumor.

The widespread use of advanced molecular techniques has led to the identification of several tumor types with PLAG1 gene fusions some of which also affect the skin and soft tissues. Herein, we present a 38-year-old female with a subcutaneous tumor affecting her forearm, which does not seem to fit into any currently recognized entity. It was a well-circumscribed tumor measuring 6 × 4,5 × 4 cm. It had a thick capsule composed of bland spindle cells forming palisades and Verocay body-like structures within a myxocollagenous background. Scattered calcifications were dispersed throughout the lesion. No cytological atypia, mitotic activity, or necrosis were present. Targeted NGS revealed a SOX10::PLAG1 fusion and fluorescent in situ hybridization confirmed the presence of PLAG1 gene rearrangement. The neoplastic cells showed a diffuse immunohistochemical expression of S100, SOX10, and PLAG1, as well as patchy desmin and CD34 positivity. The methylation profile of this tumor did not match any other entity covered by the DKFZ sarcoma classifier and apart from the gain of chromosome 12, the copy number profile was normal. The tumor was completely excised, and the patient has been free of disease for 4 years since the excision. While more cases are needed to confirm this tumor as a distinct entity, we propose a provisional name "SOX10::PLAG1-rearranged calcifying spindle cell tumor."

Intralesional leiomyosarcoma malignant transformation from a biopsied benign angioleiomyoma of the proximal anterior tibia.

We present a novel case of a malignant transformation of an extremity soft tissue angioleiomyoma to leiomyosarcoma in a man in his late 70s who presented with a painful and increasing lump on his anterior tibia. Initial imaging and biopsy showed a benign angioleiomyoma which was excised for symptomatic reasons. An analysis of the resulting specimen revealed a 50×42×15 mm smooth muscle neoplasm consistent with angioleiomyoma with a 22×11 mm entirely intralesional nodular component in keeping with a grade 1 leiomyosarcoma. The malignant constituent of the lesion was entirely encased in benign angioleiomyoma negating the need for further surgery. Systemic staging investigation revealed no evidence of metastatic disease spread final staging as per the eighth edition of the American Joint Committee on Cancer (AJCC) Staging T1N0M0 R0 Stage 1 a.

Recurrent and novel fusions detected by targeted RNA sequencing as part of the diagnostic workflow of soft tissue and bone tumours.

The identification of gene fusions has become an integral part of soft tissue and bone tumour diagnosis. We investigated the added value of targeted RNA-based sequencing (targeted RNA-seq, Archer FusionPlex) to our current molecular diagnostic workflow of these tumours, which is based on fluorescence in situ hybridisation (FISH) for the detection of gene fusions using 25 probes. In a series of 131 diagnostic samples targeted RNA-seq identified a gene fusion, BCOR internal tandem duplication or ALK deletion in 47 cases (35.9%). For 74 cases, encompassing 137 FISH analyses, concordance between FISH and targeted RNA-seq was evaluated. A positive or negative FISH result was confirmed by targeted RNA-seq in 27 out of 49 (55.1%) and 81 out of 88 (92.0%) analyses, respectively. While negative concordance was high, targeted RNA-seq identified a canonical gene fusion in seven cases despite a negative FISH result. The 22 discordant FISH-positive analyses showed a lower percentage of rearrangement-positive nuclei (range 15-41%) compared to the concordant FISH-positive analyses (>41% of nuclei in 88.9% of cases). Six FISH analyses (in four cases) were finally considered false positive based on histological and targeted RNA-seq findings. For the EWSR1 FISH probe, we observed a gene-dependent disparity (p = 0.0020), with 8 out of 35 cases showing a discordance between FISH and targeted RNA-seq (22.9%). This study demonstrates an added value of targeted RNA-seq to our current diagnostic workflow of soft tissue and bone tumours in 19 out of 131 cases (14.5%), which we categorised as altered diagnosis (3 cases), added precision (6 cases), or augmented spectrum (10 cases). In the latter subgroup, four novel fusion transcripts were found for which the clinical relevance remains unclear: NAB2::NCOA2, YAP1::NUTM2B, HSPA8::BRAF, and PDE2A::PLAG1. Overall, targeted RNA-seq has proven extremely valuable in the diagnostic workflow of soft tissue and bone tumours.

Prospective phase II trial of preoperative hypofractionated proton therapy for extremity and truncal soft tissue sarcoma: the PRONTO study rationale and design.

BACKGROUND: Oncologic surgical resection is the standard of care for extremity and truncal soft tissue sarcoma (STS), often accompanied by the addition of pre- or postoperative radiation therapy (RT). Preoperative RT may decrease the risk of joint stiffness and fibrosis at the cost of higher rates of wound complications. Hypofractionated, preoperative RT has been shown to provide acceptable outcomes in prospective trials. Proton beam therapy (PBT) provides the means to decrease dose to surrounding organs at risk, such as the skin, bone, soft tissues, and adjacent joint(s), and has not yet been studied in patients with extremity and truncal sarcoma. METHODS: Our study titled "PROspective phase II trial of preoperative hypofractionated protoN therapy for extremity and Truncal soft tissue sarcOma (PRONTO)" is a non-randomized, prospective phase II trial evaluating the safety and efficacy of preoperative, hypofractionated PBT for patients with STS of the extremity and trunk planned for surgical resection. Adult patients with Eastern Cooperative Group Performance Status ≤ 2 with resectable extremity and truncal STS will be included, with the aim to accrue 40 patients. Treatment will consist of 30 Gy radiobiological equivalent of PBT in 5 fractions delivered every other day, followed by surgical resection 2-12 weeks later. The primary outcome is rate of major wound complications as defined according to the National Cancer Institute of Canada Sarcoma2 (NCIC-SR2) Multicenter Trial. Secondary objectives include rate of late grade ≥ 2 toxicity, local recurrence-free survival and distant metastasis-free survival at 1- and 2-years, functional outcomes, quality of life, and pathologic response. DISCUSSION: PRONTO represents the first trial evaluating the use of hypofractionated PBT for STS. We aim to prove the safety and efficacy of this approach and to compare our results to historical outcomes established by previous trials. Given the low number of proton centers and limited availability, the short course of PBT may provide the opportunity to treat patients who would otherwise be limited when treating with daily RT over several weeks. We hope that this trial will lead to increased referral patterns, offer benefits towards patient convenience and clinic workflow efficiency, and provide evidence supporting the use of PBT in this setting. TRIAL REGISTRATION: NCT05917301 (registered 23/6/2023).

Multi-institutional validation of a radiomics signature for identification of postoperative progression of soft tissue sarcoma.

BACKGROUND: To develop a magnetic resonance imaging (MRI)-based radiomics signature for evaluating the risk of soft tissue sarcoma (STS) disease progression. METHODS: We retrospectively enrolled 335 patients with STS (training, validation, and The Cancer Imaging Archive sets, n = 168, n = 123, and n = 44, respectively) who underwent surgical resection. Regions of interest were manually delineated using two MRI sequences. Among 12 machine learning-predicted signatures, the best signature was selected, and its prediction score was inputted into Cox regression analysis to build the radiomics signature. A nomogram was created by combining the radiomics signature with a clinical model constructed using MRI and clinical features. Progression-free survival was analyzed in all patients. We assessed performance and clinical utility of the models with reference to the time-dependent receiver operating characteristic curve, area under the curve, concordance index, integrated Brier score, decision curve analysis. RESULTS: For the combined features subset, the minimum redundancy maximum relevance-least absolute shrinkage and selection operator regression algorithm + decision tree classifier had the best prediction performance. The radiomics signature based on the optimal machine learning-predicted signature, and built using Cox regression analysis, had greater prognostic capability and lower error than the nomogram and clinical model (concordance index, 0.758 and 0.812; area under the curve, 0.724 and 0.757; integrated Brier score, 0.080 and 0.143, in the validation and The Cancer Imaging Archive sets, respectively). The optimal cutoff was - 0.03 and cumulative risk rates were calculated. DATA CONCLUSION: To assess the risk of STS progression, the radiomics signature may have better prognostic power than a nomogram/clinical model.

Clinical features of patients with carcinoma soft tissue metastases as surgical indications: a retrospective cohort study.

BACKGROUND: Soft-tissue metastasis of carcinoma is rare. In the present study, we investigated the surgical indications and clinical features of patients with soft tissue metastases of carcinoma. METHODS: In this retrospective cohort study, we enrolled 26 patients with soft tissue carcinoma metastasis referred to our department for treatment. Sex, age, location, size, depth, pain due to the tumor, primary origin, serum C-reactive protein (CRP) level, MRI examinations, diagnosis by a previous physician, carcinoma markers from blood, history of carcinoma, other metastases, performance status (PS), and surgical procedures were documented. Associations between variables and surgery were statistically analyzed. RESULTS: The primary cancer origin was found to be the lung (n = 10), kidney (n = 7), esophagus (n = 2), stomach (n = 1), breast (n = 1), liver (n = 1), ureter (n = 1), anus (n = 1), and unknown (n = 2). The mean CRP level of all patients was 2.3 mg/dL. Seven tumors (26.9%) were originally suspected to be soft tissue metastases of carcinoma, while 19 tumors (73.1%) were considered soft tissue sarcomas or inflammatory lesions by the previous treating physician. Twenty patients (76.9%) had other metastases. The PS of the 12 patients (46.2%) was zero. Eleven patients (42.3%) underwent surgery for soft tissue metastases. Diagnosis of soft tissue metastasis by a previous physician and good PS (p < 0.05) were significantly associated with surgery. CONCLUSION: Overall, the present results show that surgical indications for soft tissue metastasis of carcinoma include diagnosis by the referring physician or good PS of the patients.

The Role of Methylation Analysis in Distinguishing Cellular Myxoma from Low-Grade Myxofibrosarcoma.

Cellular myxoma is a benign soft tissue tumor frequently associated with GNAS mutation that may morphologically resemble low-grade myxofibrosarcoma. This study aimed to identify the undescribed methylation profile of cellular myxoma and compare it to myxofibrosarcoma. We performed molecular analysis on twenty cellular myxomas and nine myxofibrosarcomas and analyzed the results using the methylation-based DKFZ sarcoma classifier. A total of 90% of the cellular myxomas had GNAS mutations (four loci had not been previously described). Copy number variations were found in all myxofibrosarcomas but in none of the cellular myxomas. In the classifier, none of the cellular myxomas reached the 0.9 threshold. Unsupervised t-SNE analysis demonstrated that cellular myxomas form their own clusters, distinct from myxofibrosarcomas. Our study shows the diagnostic potential and the limitations of molecular analysis in cases where morphology and immunohistochemistry are not sufficient to distinguish cellular myxoma from myxofibrosarcoma, particularly regarding GNAS wild-type tumors. The DKFZ sarcoma classifier only provided a valid prediction for one myxofibrosarcoma case; this limitation could be improved by training the tool with a more considerable number of cases. Additionally, the classifier should be introduced to a broader spectrum of mesenchymal neoplasms, including benign tumors like cellular myxoma, whose distinct methylation pattern we demonstrated.

Two cases of inflammatory myofibroblastic tumor treated with targeted drugs: A case report.

INTRODUCTION: Inflammatory myofibroblastic tumor (IMT) is a rare invasive soft tissue tumor. Many IMTs are positive for anaplastic lymphoma kinase (ALK) with ALK gene fusion; other gene mutations have also been reported, which indicates a key role for genetic testing and the development of target therapy to optimize treatment strategies. PATIENT CONCERNS: We report 2 patients who obtained clinical benefits following targeted treatment with ensartinib. DIAGNOSIS: The first patient was diagnosed as IMT, with TFG-ROS1 fusion gene mutation. The second patient was IMT harboring the ALK-STRN fusion gene mutation. INTERVENTIONS: We performed gene testing for these 2 patients. According to the test result, both patients received ensartinib 225 mg QD as targeted therapy for a 30-day cycle. OUTCOMES: The first patient achieved partial remission and maintained a stable state for 14.7 months. The second patient was treated for 10 months and reached complete remission after 5 months and is currently still benefiting from treatment. Treatment-related side effects were mild in both patients. CONCLUSION: Our cases provided some new insights and approaches for the clinical diagnosis and treatment of IMT.

Superior scapular location: An overlooked albeit frequent finding in elastofibroma dorsi.

PURPOSE: To explore the frequency of superior scapular elastofibroma dorsi in a large patient series with elastofibroma dorsi. METHODS: 136 chest CTs from January 2016 to July 2022 reporting elastofibroma dorsi were retrospectively analyzed. Three radiologists assessed the number, size, and location of elastofibroma dorsi. Continuous variables underwent two-tailed t-tests with p < 0.05. Inter-observer agreement was assessed by using Cohen's Kappa values. RESULTS: In 136 patients (mean age, 75.9 +/- 9.8 years; 117 female), 330 elastofibroma dorsi were found. Six (4.4 %) patients had single, 87 (64 %) double, 22 (16.2 %) triple and 21 (15.4 %) quadruple lesions. All single and double lesions were in the inferior scapular regions. 43 (31.6 %) patients had superior scapular lesions in addition to inferior scapular elastofibroma dorsi. Inferior scapular elastofibroma dorsi was significantly larger than superior scapular elastofibroma dorsi. The probability of a right superior lesion was significantly higher in patients with a larger right inferior lesion. Inter-observer agreement was very good for experienced radiologist (κ = 94.1) and good for other radiologists (κ = 79.4 and κ = 78). CONCLUSION: In contrast to current belief, superior scapular elastofibroma dorsi accompanying the typical inferior scapular lesions is not uncommon and can even manifest bilaterally. To the best of our knowledge, this is the first case series reporting prevalence of quadruple elastofibroma dorsi.

Tumours of the foot: A 10 years retrospective analysis.

INTRODUCTION: The foot is a complex structure composed of several tissues, each of which can be the origin of the proliferation and development of the tumour. Most lesions about the foot are reactive or inflammatory, but some are true neoplasms. METHOD: This is a retrospective analysis of 4997 patient records treated in the Orthopaedic Oncology Unit of University Malaya Medical Centre, Malaysia, between 1 January 2010 to 31 December 2020. Demographic data of 195 patients with foot tumours were analysed out of 4997 neoplasm patients. RESULTS: There were 195 cases of foot tumours: 148 were benign, and 47 were malignant. 47 were bone tumours, 4 were metastases, and 144 were soft tissue tumours. Six patients succumbed to the disease, two cases of giant cell tumour (GCT) and one patient with synovial sarcoma had a recurrence. Treatment of foot tumours was wide resection in general. However, in metastasis cases, amputation was done. The majority of tumours were in the toes and dorsum of the foot. Soft tissue tumours of the foot occur in the elderly population in contrast to bone tumours, mainly in the second decade of life. The gender distribution was almost equal for foot tumours. Ganglion and Giant Cell Tumour of the bone are the commonest benign soft tissue and bone tumours. The most common malignant soft tissue and bone tumours are malignant melanoma and chondrosarcoma. The amputation rate is 5.64% the recurrence rate is 1.54%. Mortality rate is 3.08%. The MSTS score is 79%, and the TESS score is 76.23%. CONCLUSION: Foot tumours are relatively rare, mostly originating from soft tissue and exhibiting a benign nature. Nonetheless, a noteworthy proportion-approximately a quarter of these tumours-demonstrate malignancy. The surgical interventions undertaken in managing these tumours and associated functional outcomes generally yield acceptable results.

Impact of resection margin on outcome in soft-tissue sarcomas of the extremities treated with limb-sparing surgery and postoperative radiotherapy.

BACKGROUND: The standard curative treatments for extremity soft tissue sarcoma (ESTS) include surgical resection with negative margins and perioperative radiotherapy. However, the optimal resection margin remains controversial. This study aimed to evaluate the outcomes in ESTS between microscopically positive margin (R1) and microscopically negative margin (R0) according to the Union for International Cancer Control (UICC) (R + 1 mm) classification. METHODS: Medical records of patients with localized ESTS who underwent primary limb-sparing surgery and postoperative radiotherapy between 2004 and 2015 were retrospectively reviewed. Patients were followed for at least 5 years or till local or distant recurrence was diagnosed during follow-up. Outcomes were local and distal recurrences and survival. RESULTS: A total of 52 patients were included in this study, in which 17 underwent R0 resection and 35 underwent R1 resection. No significant differences were observed in rates of local recurrence (11.4% vs. 35.3%, p = 0.062) or distant recurrence (40.0% vs. 41.18%, p = 0.935) between R0 and R1 groups. Multivariate analysis showed that distant recurrences was associated with a Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade (Grade III vs. I, adjusted hazard ratio (aHR): 12.53, 95% confidence interval (CI): 2.67-58.88, p = 0.001) and tumor location (lower vs. upper extremity, aHR: 0.23, 95% CI: 0.07-0.7, p = 0.01). Kaplan-Meier plots showed no significant differences in local (p = 0.444) or distant recurrent-free survival (p = 0.161) between R0 and R1 groups. CONCLUSIONS: R1 margins, when complemented by radiotherapy, did not significantly alter outcomes of ESTS as R0 margins. Further studies with more histopathological types and larger cohorts are necessary to highlight the path forward.

[Detection of EWSR1 gene rearrangement by fluorescence in situ hybridization in bone and soft tissue tumors: clinical application evaluation and atypical signal analysis].

Objective: To investigate the clinical application of EWSR1 gene rearrangement by fluorescence in situ hybridization (FISH) in bone and soft tissue tumors and to analyze the cases with atypical signal pattern. Methods: The cases detected for EWSR1 gene rearrangement by FISH in Beijing Jishuitan Hospital, Capital Medical University from 2014 to 2021 were collected, and the value of detecting EWSR1 gene rearrangement for diagnosing bone and soft tissue tumors was analyzed. The cases with atypical positive signals were further analyzed by next generation sequencing (NGS). Results: FISH using EWSR1 break-apart probe kit was successfully performed in 97% (205/211) of cases, 6 cases failed. Four of the 6 failures were due to improper decalcification, 1 case due to signal overlap caused by thick slices, and 1 case due to signal amplification and disorder. EWSR1 gene rearrangements were positive in 122 cases (122/205, 59%), atypical positive signal in 8 cases (8/205, 4%), and negative in 75 cases (75/205, 37%). In cases testing positive, the percentage of positive cells ranged from 34% to 98%, with 120 cases (120/122, 98%) showing a positive cell percentage greater than 50%. Among the 205 successfully tested cases, 156 cases were histologically diagnosed as Ewing's sarcoma, of which 110 were positive (110/156, 71%), 7 were atypical positive (7/156, 4%), and 39 were negative (39/156, 25%). Nine cases were histologically diagnosed as clear cell sarcoma of soft tissue, of which 6 were positive (6/9), 1 was atypical positive (1/9), and 2 were negative (2/9). Five cases were histologically diagnosed as extraskeletal myxoid chondrosarcoma, of which 2 were positive (2/5) and 3 were negative (3/5). Three cases were histologically diagnosed as angiomatoid fibrous histiocytoma, of which 2 were positive (2/3) and 1 was negative (1/3). Two cases were histologically diagnosed as myoepithelioma of soft tissue, of which 1 was positive (1/2) and 1 was negative (1/2). One case was histologically diagnosed as olfactory neuroblastoma with a positive result. The 29 other tumor cases including osteosarcoma, synovial sarcoma, and malignant melanoma and others were all negative. Basing on histology as the standard for diagnosis and considering atypical positive cases as negative, comparing with the 29 cases of other tumors as control group, the sensitivity for diagnosing Ewing's sarcoma through the detection of EWSR1 gene rearrangement was 71%, and the specificity was 100%; the sensitivity for diagnosing clear cell sarcoma of soft tissue was 67%, and the specificity was 100%; the sensitivity for diagnosing extraskeletal myxoid chondrosarcoma was 40%, and the specificity was 100%; the sensitivity for diagnosing angiomatoid fibrous histiocytoma was 67%, and the specificity was 100%; the sensitivity for diagnosing myoepithelioma of soft tissue was 50%, and the specificity was 100%; the sensitivity for diagnosing olfactory neuroblastoma was 100%, and the specificity was 100%. Four of 8 cases with atypical positive signals analyzed by NGS showed EWSR1 rearrangement, including EWSR1::FLI1 in one case of Ewing sarcoma, EWSR1::NFATC2 in one case of EWSR1::NFATC2-rearranged sarcoma, EWSR1::ATF1 in one case of clear cell sarcoma of soft tissue and EWSR1::NR4A3 in one case of extraskeletal myxoid chondrosarcoma. Conclusions: Detection of EWSR1 rearrangement by FISH is of utmost significance in the diagnosis of bone and soft tissue tumors. Cases with atypical positive signals should be further scrutinized, correlating with their histomorphology and verifying by NGS if necessary.

[Congenital spindle cell/sclerosing rhabdomyosarcoma: a clinicopathological analysis].

Objective: To investigate the clinicopathological features, immunophenotype and molecular genetic characteristics of congenital spindle cell/sclerosing rhabdomyosarcoma. Methods: Sixteen cases (including 10 consultation cases) of congenital spindle cell/sclerosing rhabdomyosarcoma diagnosed at the Beijing Children's Hospital, Capital Medical University, Beijing China, from April 2017 to January 2022 were collected. These cases were evaluated for clinical profiles, histomorphological features, immunophenotype and molecular characteristics. Results: Among the 16 patients, 9 were male and 7 were female. Five cases were present during maternal pregnancy and 11 cases were found immediately after birth. The tumors were located in the chest wall, low back, retroperitoneum, extremities or perineum. The tumors consisted of fasciculated spindle-shaped cells with localized mesenchymal sclerosis and vitreous metaplasia. Immunohistochemistry showed that the tumor cells expressed Desmin, Myogenin, MyoD1, SMA, CD56 and ALK to varying degrees, but not other markers such as CD34, CD99, pan-TRK, S-100 and BCOR. FISH analyses with NCOA2 (8q13) and VGLL2 (6q22) gene breakage probes revealed a breakage translocation in chromosome NCOA2 (8q13) in 4 cases (4/11). In the 6 cases subject to sequencing, a mutation at the p.L122R locus of MYOD1 gene was detected in 1 case (1/6). Two cases were examined by electron microscopy, which showed bundle-arranged myofilaments with some primitive myofilament formation. Five cases were resected with simple surgery, 2 cases were biopsied and followed up with observation only, and 9 cases were treated with surgery and adjuvant chemotherapy. Follow-up was available in 12 cases. At the end of the follow-up, 2 of the 12 patients developed local recurrences and 2 patients survived with disease. Conclusions: Congenital spindle cell/sclerosing rhabdomyosarcoma is a rare subtype of congenital rhabdomyosarcoma. It more commonly occurs in the chest, back and lower limbs of infants than other sites. NCOA2/VGLL2 gene fusion seems to be the most common genetic change. Its prognosis is better than other subtypes of rhabdomyosarcoma and those in adolescents and adults with the same subtype. Analysis and summary of its clinicopathological features can help differentiate it from other soft tissue tumors in infants and children and provide the information for appropriate treatments.

Psammomatoid ossifying fibroma in the frontal sinus: An intriguing clinical encounter-A detailed case report.

BACKGROUND: Psammomatoid ossifying fibroma (POF) is a rare craniofacial neoplasm, primarily affecting the maxillofacial region, and typically observed in adolescents and young adults. This case report presents a unique occurrence of POF in a 50-year-old male, defying the conventional age range and exhibiting an unusual anatomical location within the frontal sinus. CASE: A 50-year-old male with a prior history of cecal adenocarcinoma and colectomy presented with left eye proptosis and new-onset headaches. Imaging revealed a well-defined calcified mass in the left frontal sinus, leading to a diagnosis of POF. Open surgical resection was performed to remove the tumor, and histopathological evaluation confirmed its diagnosis as psammomatoid ossifying fibroma. The patient exhibited no postoperative complications or signs of recurrence. CONCLUSION: This case underscores the diverse clinical presentations and diagnostic challenges associated with POF, emphasizing the importance of accurate diagnosis and multidisciplinary collaboration. Further research is needed to explore the genetic underpinnings and optimal management strategies for this intriguing condition.

Cytomorphology of metastatic colonic MXD4::NUTM1-rearranged sarcoma.

This report describes the cytologic features of a recently described MXD4::NUTM1-rearranged colonic sarcoma metastatic to the midclavicular soft tissue. Thirteen years ago, a 65-year-old woman presented with a cecal mass and subsequent liver mass. The cecal mass was diagnosed as malignant undifferentiated spindled and epithelioid neoplasm based on morphology and lack of tumor immunoreactivity with a panel of epithelial, smooth muscle, skeletal, melanoma, hematologic, and GIST markers. The liver mass showed morphologic and immunophenotypic similarity to the epithelioid component of the patient's cecal mass, albeit devoid of the spindled component. Fine needle aspiration of the midclavicular soft tissue mass showed singly scattered to clustered epithelioid to rhabdoid tumor cells with centrally to eccentrically located nuclei, prominent nucleoli, and moderate eosinophilic cytoplasm. Immunohistochemical stains performed on the concurrent biopsy showed the tumor cells were positive for NUT and negative for all other additional markers with retained normal expression of SMARCA2 and SMARCA4. Next-generation sequencing showed the presence of MXD4::NUTM1 gene fusion. Due to the identical cytomorphologic findings with the epithelioid component of the patient's prior cecal and liver masses, the tumor was deemed as consistent with a NUTM1-rearranged sarcoma. To our knowledge, this case represents the first reported cytologic features of a NUTM1-rearranged sarcoma on fine needle aspiration. Familiarity with the cytologic features, inclusion of this entity in the differential diagnosis of tumors with epithelioid and/or rhabdoid morphology, and performance of ancillary tests (immunohistochemistry and molecular) will be helpful in arriving at the right diagnosis.

Prognostic Factors Associated with Tumor Recurrence and Overall Survival in Soft Tissue Sarcomas of the Extremities in a Colombian Reference Cancer Center.

Introduction: Soft tissue sarcomas (STS) are low-incidence tumors whose clinical and histopathological factors are associated with adverse oncological outcomes. This study evaluated prognostic factors (PF) associated with tumor recurrence and overall survival (OS) in patients diagnosed with STS of the extremities, treated at the Instituto Nacional de Cancerología (INC), Bogotá, Colombia. Materials and Methods: An analytical observational study of a historical cohort was carried out, including patients diagnosed with STS and managed surgically in the Functional Unit for Breast and Soft Tissue Tumors of the INC from January 2008 to December 2018. Results: A total of 227 patients were included; 74.5% had tumors greater than 5 cm. Most patients (29.1%) were in stage IIIB at diagnosis. Age was associated with higher mortality (HR = 1.01; CI95%: 1-1.02; p = 0.048). Tumor persistence at admission to the INC (HR = 2.34; CI95%: 1.25-4.35; p = 0.007) and histologic grade III (HR = 5.36; CI95%: 2.29-12.56; p = <0.001) showed statistical significance in the multivariate analysis for recurrence of any type, as did the PFs associated with a higher risk of local recurrence (HR = 2.85; CI95%: 1.23-6.57; p = 0.014 and HR = 6.09; CI95%: 2.03-18.2; p = 0.001), respectively. Tumor size (HR = 1.03; CI95%: 1-1.06; p = 0.015) and histologic grade III (HR = 4.53; CI95%: 1.42-14.49; p = 0.011) were associated with a higher risk of distant recurrence. Conclusions: This cohort showed that in addition to histologic grade and tumor size, tumor persistence at the time of admission has an impact on disease recurrence, so STS should be managed by a multidisciplinary team with experience in this pathology in high-volume reference centers.