Solitary Fibrous Tumor Requiring Abdominal Aortic Vessel Replacement.

Solitary fibrous tumors (SFTs) are mesenchymal tumors, and retroperitoneal occurrence is rare. It has been identified in a variety of soft tissues and organs, such as the pleura, peritoneum, and meninges. In this case, the tumor was in contact with the abdominal aorta, and the invasion was difficult to judge preoperatively. Intraoperatively, it was revealed that the tumor could not be completely removed without aortic replacement. Although SFTs have a generally good prognosis, certain factors, such as tumor incomplete resection, have been reported to increase the risk of recurrence and metastasis. We were able to completely remove the tumor by performing a combined resection of the aorta. The specimens were microscopically disorganized proliferation of spindle-shaped cells. Immunostaining was positive for cluster of differentiation 34 (CD34) and signal transducer and activator of transcription 6 (STAT6). The tumor cells infiltrating into aortic adventitia were observed. This is a valuable case in which artificial blood vessel replacement was able to reduce the risk of recurrence and metastasis due to tumor remnants. We report a rare case of SFT resected with artificial blood vessel replacement.

Renal preservation in immediate bifurcation of the renal artery in a solitary kidney using inner branch in a physician-modified, fenestrated-branched endovascular graft.

For high-risk patients with complex aortic aneurysms and post-dissection aneurysms, fenestrated and branched endovascular aortic repair (F/BEVAR) offers minimally invasive options customized to each individual's anatomy. Company-manufactured devices or physician-modified endovascular grafts performed under the purview of an investigational device exemption are two United States Food and Drug Administration-approved avenues to perform fenestrated and branched endovascular aortic repair. This case report describes a creative use of physician-modified endograft to salvage renal function in a solitary kidney with a near immediate bifurcation of the renal artery in a patient with post-dissection extent II thoracoabdominal aortic aneurysm. In our patient, the immediate bifurcation (2 mm distal to the common left renal artery orifice) of the left renal artery in the setting of a known long-standing occlusion of a remotely placed right renal stent presented a clinical and technical challenge to maintaining this patient's kidney function without sacrificing a significant portion of his remaining solitary kidney. Additionally, each branch was sizeable (5 and 7 mm), perfusing the cranial and caudal half of the kidney, respectively. Early bifurcation of renal arteries often results in sacrifice of the smaller branch to obtain adequate target vessel seal. Although some analyses have shown no change in glomerular filtration rate from coverage of accessory renal arteries, more recent studies have indicated clinically significant drops in both glomerular filtration rate and kidney length at 2-year follow-up. Herein, we describe use of a combination of an inner and external branch modification to stent both branches to preserve renal parenchyma and function. The patient has provided written informed consent for publication of this case report and their associated imaging studies.

Epigenomic and transcriptomic profiling of solitary fibrous tumors identifies site-specific patterns and candidate genes regulated by DNA methylation.

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm which can arise at any anatomic site and is characterized by recurrent NAB2::STAT6 fusions and metastatic progression in 10-30%. The cell of origin has not been identified. Despite some progress in understanding the contribution of heterogeneous fusion types and secondary mutations to SFT biology, epigenetic alterations in extrameningeal SFT remain largely unexplored, and most sarcoma research to date has focused on the use of methylation profiling for tumor classification. We interrogated genome-wide DNA methylation in 79 SFTs to identify informative epigenetic changes. RNA-seq data from targeted panels and data from the Cancer Genome Atlas (TCGA) were used for orthogonal validation of selected findings. In unsupervised clustering analysis, the top 500 most variable CpGs segregated SFTs by primary anatomic site. Differentially methylated genes (DMGs) associated with primary SFT site included EGFR, TBX15, multiple HOX genes and their cofactors EBF1, EBF3, and PBX1, as well as RUNX1 and MEIS1. Of the 20 DMGs that were interrogated on the RNA-seq panel, twelve were significantly differentially expressed according to site. However, with the exception of TBX15, most of these also showed differential expression according to NAB2::STAT6 fusion type, suggesting that the fusion oncogene contributes to transcriptional regulation of these genes. Transcriptomic data confirmed an inverse correlation between gene methylation and the expression of TBX15 in both SFT and TCGA sarcomas. TBX15 also showed differential mRNA expression and 5' UTR methylation between tumors located in different anatomic sites in TCGA data. In all analyses, TBX15 methylation and mRNA expression retained the strongest association with tissue of origin in SFT and other sarcomas, suggesting a possible marker to distinguish metastatic tumors from new primaries without genomic profiling. Epigenetic signatures may further help to identify SFT progenitor cells at different anatomic sites.

Preoperative MRI-based radiomic nomogram for distinguishing solitary fibrous tumor from angiomatous meningioma: a multicenter study.

Purpose: This study evaluates the efficacy of radiomics-based machine learning methodologies in differentiating solitary fibrous tumor (SFT) from angiomatous meningioma (AM). Materials and methods: A retrospective analysis was conducted on 171 pathologically confirmed cases (94 SFT and 77 AM) spanning from January 2009 to September 2020 across four institutions. The study comprised a training set (n=137) and a validation set (n=34). All patients underwent contrast-enhanced T1-weighted (CE-T1WI) and T2-weighted(T2WI) MRI scans, from which 1166 radiomics features were extracted. Subsequently, seventeen features were selected through minimum redundancy maximum relevance (mRMR) and the least absolute shrinkage and selection operator (LASSO). Multivariate logistic regression analysis was employed to assess the independence of these features as predictors. A clinical model, established via both univariate and multivariate logistic regression based on MRI morphological features, was integrated with the optimal radiomics model to formulate a radiomics nomogram. The performance of the models was assessed utilizing the area under the receiver operating characteristic curve (AUC), accuracy (ACC), sensitivity (SEN), specificity (SPE), positive predictive value (PPV), and negative predictive value (NPV). Results: The radiomics nomogram demonstrated exceptional discriminative performance in the validation set, achieving an AUC of 0.989. This outperformance was evident when compared to both the radiomics algorithm (AUC= 0.968) and the clinical model (AUC = 0.911) in the same validation sets. Notably, the radiomics nomogram exhibited impressive values for ACC, SEN, and SPE at 97.1%, 93.3%, and 100%, respectively, in the validation set. Conclusions: The machine learning-based radiomic nomogram proves to be highly effective in distinguishing between SFT and AM.

Large malignant solitary fibrous tumour of the pleura and tumour doubling time: A case report and literature review.

INTRODUCTION AND CLINICAL IMPORTANCE: Solitary fibrous tumours of the pleura (SFTPs) are rare, often benign, localized fibrous tumours. SFTPs are surgically excised after discovery. Herein, we report a rare case in which the tumour doubling time (TDT) was measured. CASE PRESENTATION: A 71-year-old male patient with a history of cataract surgery presented with back pain and dyspnoea on exertion. Chest radiography revealed a large mass in the left thorax measuring 135 × 80-mm, after pleural effusion drainage. A thoracic tumour had been identified on a preoperative medical examination for cataract surgery 4 years previously; however, the patient did not opt for treatment. Chest radiography revealed a 43 × 22-mm mass. The TDT calculated using the Schwarz method, was 284 days. The tumour was resected and diagnosed as an SFTP. The postoperative course was uneventful, and the patient was discharged on postoperative day 9. No evidence of recurrence was observed one year and three months postoperatively. CLINICAL DISCUSSION: The malignant form of SFTPs remains unclear. The TDT of malignant SFPTs tends to be shorter than that of benign SFTPs in previous reports. However, in this case, despite the diagnosis of malignant SFT, the TDT was 284 days, which was longer than in previous reports. CONCLUSIONS: Compared with previous reports, there appeared to be no correlation between the risk of metastases and TDT. Few reports have calculated the TDT of SFPTs, and further accumulation of cases is desirable.

Tolerant mothers: aggression does not explain solitary living in the bush Karoo rat.

Many mammal species are thought to adopt solitary living owing to mothers becoming intolerant of adult offspring and the occurrence of social intolerance between adults. However, field studies on how solitary mammals interact are rare. Here we show that solitary living can occur without social intolerance. Over 3 years, we recorded interactions between free-living bush Karoo rats (Otomys unisulcatus) and conducted dyadic encounter experiments between kin and non-kin female neighbours, both in a neutral test arena and in field intruder experiments. Social interactions were rare (230/2062 observations), and they were aggressive in only 34% of cases. In dyadic encounters, mothers interacted amicably with young offspring. Aggression between mothers and offspring was almost absent. This mother-offspring relationship remained amicable even after adult offspring had dispersed. Aggression between neighbouring adult females was low in neutral arena tests, independent of kinship and season. However, in the field, females reacted more aggressively towards non-kin than kin intruders, especially during the breeding season. Tolerance between mothers and adult offspring indicates that aggression is not the mechanism leading to dispersal and solitary living. We found a solitary social system characterized by social tolerance, suggesting that dispersal and lack of social attraction rather than aggression can lead to solitary living.

Challenges in the Management of Recurrent CNS Solitary Fibrous Tumors: A Case Report.

Solitary fibrous tumors (SFTs) of the central nervous system (CNS) are rare mesenchymal neoplasms with diverse histological characteristics ranging from benign to malignant. Their higher chance for metastasis and recurrence poses significant diagnostic and therapeutic challenges. In this study, we present a 53-year-old female with a recurrent SFT of the cervical spine that was diagnosed initially 12 years ago. The patient underwent repeated surgical resections including laminectomy and gamma knife radiosurgery, as well as temozolomide, bevacizumab, and pazopanib therapy. Despite these interventions, she experienced continuous disease progression, with the cancer spreading to vital CNS locations. This study demonstrates the locally invasive nature of CNS SFTs and their complicated treatments involving surgical excision, radiotherapy, and systemic chemotherapy. This study highlights the need for new therapeutic approaches, as the existing methods fall short in meeting all the requirements and continue to lag in targeted therapy research for CNS SFTs. Consequently, it is important to develop individualized treatment strategies for patients affected by such difficult conditions.

Selective Serotonin Reuptake Inhibitors and Solitary Rectal Ulcer Syndrome: A Bloody Relationship.

Introduction: Solitary rectal ulcer syndrome (SURS) is a poorly understood and uncommon benign disorder of the lower gastrointestinal tract. It presents with various symptoms, often misinterpreted as inflammatory bowel disease. To date, there is no association between the use of selective serotonin reuptake inhibitors (SSRIs) and SURS. Case description: A 29-year-old male on paroxetine for six months and with a non-contributory surgical history presented to the clinic due to three months of haematochezia, abdominal pain and mucoid discharge. Physical examination and a review of systems were unremarkable; a colonoscopy demonstrated a suspicious ulcerated lesion in the rectum, which was identified as SURS on biopsy. The patient was advised lifestyle and dietary modifications. In addition, paroxetine was discontinued, and patient was switched to venlafaxine, a serotonin-norepinephrine reuptake inhibitor. Subsequently, the patient's symptoms resolved gradually, and he did not report any signs of recurrence on follow-up. Conclusion: Literature confirms that SSRIs can increase the occurrence of GI ulceration yet focuses specifically on upper gastrointestinal bleeding rather than rectal bleeding. This finding raises the need for further research. LEARNING POINTS: SURS is often underdiagnosed or misdiagnosed as inflammatory bowel disease.The pathophysiology and aetiology behind SURS remain obscure.This case points to a potential correlation between SSRIs use and SURS development.

Ascending Vagal Sensory and Central Noradrenergic Pathways Modulate Retrieval of Passive Avoidance Memory in Male Rats.

Visceral feedback from the body is often subconscious, but plays an important role in guiding motivated behaviors. Vagal sensory neurons relay "gut feelings" to noradrenergic (NA) neurons in the caudal nucleus of the solitary tract (cNTS), which in turn project to the anterior ventrolateral bed nucleus of the stria terminalis (vlBNST) and other hypothalamic-limbic forebrain regions. Prior work supports a role for these circuits in modulating memory consolidation and extinction, but a potential role in retrieval of conditioned avoidance remains untested. To examine this, adult male rats underwent passive avoidance conditioning. We then lesioned gut-sensing vagal afferents by injecting cholecystokinin-conjugated saporin toxin (CSAP) into the vagal nodose ganglia (Experiment 1), or lesioned NA inputs to the vlBNST by injecting saporin toxin conjugated to an antibody against dopamine-beta hydroxylase (DSAP) into the vlBNST (Experiment 2). When avoidance behavior was later assessed, rats with vagal CSAP lesions or NA DSAP lesions displayed significantly increased conditioned passive avoidance. These new findings support the view that gut vagal afferents and the cNTSNA-to-vlBNST circuit play a role in modulating the expression/retrieval of learned passive avoidance. Overall, our data suggest a dynamic modulatory role of vagal sensory feedback to the limbic forebrain in integrating interoceptive signals with contextual cues that elicit conditioned avoidance behavior.

Navigating Solitary Rectal Ulcer Syndrome: A Surgeon's Conundrum With Rectal Carcinoma in a Young Adult.

Solitary rectal ulcer syndrome is a rare, chronic, and benign disorder. It can be observed as ulcers in the rectal mucosa, solitary or multiple lesions. It can often be misdiagnosed with other intestinal morbidities, due to its clinical similarities. It can be diagnosed by clinical symptoms, radiological tools, and histopathological examination. Management is carried out by conservative methods such as lifestyle and dietary modifications with medical and surgical therapy. This is a case of a 37-year-old female with a major complaint of per-rectal bleeding. Proctoscopy revealed an irregular-ulcerated mass in the rectum, which was managed conservatively. The patient showed improved symptoms after a colonoscopy, at a six-month follow-up.

Adding Evidence to Plasmacytoma: A Case Series.

Plasmacytoma is a rare tumor of plasma cells with two primary variants: solitary bone plasmacytoma (SBP) and extramedullary plasmacytoma (EMP). It poses diagnostic challenges at times. Radiotherapy (RT) is the curative modality in the majority of cases. We share a case series with the aim of adding evidence to the literature about plasmacytoma and its clinical presentation, diagnostic challenges, and outcome with RT.

Solitary metastasis to the head of the pancreas from lung adenocarcinoma mimicking pancreatic ductal adenocarcinoma: A case report.

Solitary pancreatic metastasis is a rare cause of pancreatic neoplasm. Pancreatic ductal adenocarcinoma is the primary differential consideration when a solitary pancreatic mass is diagnosed, as it is the most common solitary solid pancreatic neoplasm. A majority of pancreatic ductal adenocarcinomas arise in the region of the head of the pancreas; however, specific neoplastic and non-neoplastic lesions can occur at or adjacent to the pancreatic head, which can mimic a pancreatic ductal adenocarcinoma. Therefore, a histopathological diagnosis is essential for confirming pancreatic ductal adenocarcinoma. Isolated solitary metastasis from primary lung adenocarcinoma is a rare cause of a solitary pancreatic head mass. We report a case in which imaging and pathology were integral to the diagnosis of a solitary lung adenocarcinoma metastasis to the head of the pancreas, which ultimately guided appropriate patient management.

Possible Genetic Links Between Solitary Fibrous Tumor and Pancreatic Cancer: A Rare Case of Solitary Fibrous Tumor and Pancreatic Cancer Concurrence.

Pancreatic ductal adenocarcinoma is the most prevalent form of pancreatic cancer, originating in the duct lining of the pancreas. The simultaneous occurrence with a solitary fibrous tumor (SFT) represents an unexpected finding. We present a case involving a 64-year-old female with synchronous pancreatic cancer and SFT. The patient initially experienced severe abdominal pain, visible jaundice, and itching. Diagnostic imaging revealed a mass in the head of the pancreas and a soft tissue mass in the right hemipelvis. Further investigations included histological examination, immunohistochemistry, and genetic testing. Subsequently, the patient underwent appropriate management, which involved the excision of both masses and radiochemotherapy. The discussion focuses on the genetic linkages in this rare presentation, aiming to identify treatment connections for both tumors. Throughout this case report, our aim is to contribute to enriching the limited literature with new insights and underscore the importance of identifying genetic linkages between both tumors which may lead to more effective management strategies and better treatment outcomes.

Decoding the identity of rare tumors.

Solitary fibrous tumors have gene expression signatures similar to those of neuroendocrine tumors.

Clinical outcomes of patients undergoing reoperation with solitary fibrous tumors/hemangiopericytomas and malignant progression of tumors.

OBJECTIVE: The purpose of this study was to analyze the clinical outcomes and malignant progression of tumors in patients who underwent reoperation for recurrent solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs). METHODS: We identified 48 patients who underwent reoperation because of tumor recurrence at Tangdu Hospital between January 2010 and December 2021 and analyzed the clinical outcomes, namely, the rate of gross total resection (GTR), progression-free survival (PFS), overall survival (OS), malignant progression of tumors and radiotherapy. The survival curves for each group were plotted using the Kaplan‒Meier method and compared using log-rank tests. RESULTS: Of the 48 patients (25 men and 23 women, mean age 49.5 ± 14.3 years), 25 experienced a second recurrence or metastasis, 15 of whom underwent a third surgery, and the remaining 10 patients who did not undergo surgery ultimately died after tumor progression. The median time (95% CI) to tumor recurrence was 40.0 (32.3-47.7) months after reoperation, with 3-, 5- and 10-year PFS rates of 54.6%, 29.5% and 14.8%, respectively. The median (95% CI) survival time was 70.0 (46.6-93.4) months, with 3-, 5- and 10-year survival rates of 67.9%, 55.1% and 36.7%, respectively. Among the 48 patients who underwent reoperation, 27 (56.3%) achieved GTR, and 21 (43.8%) achieved STR. Twelve patients in the GTR group (12/27, 44.4%) received radiotherapy after surgery, and 18 patients in the STR group (18/21, 85.7%) received radiotherapy. Of the 48 recurrent SFTs, 24 were classified as WHO grade 1, 14 were classified as WHO grade 2, and 10 were classified as WHO grade 3 based on 2021 WHO classification after the primary operation. After reoperation, 9 tumors developed malignant progression, including 4 WHO grade 1 tumors progressing to WHO grade 2 tumors, 1 WHO grade 1 tumor progressing to a WHO grade 3 tumor and 4 WHO grade 2 tumors progressing to WHO grade 3 tumors. CONCLUSIONS: GTR after reoperation was associated with better PFS and OS compared to STR. However, the PFS after the third surgery was significantly shorter than that after the second surgery, and the rate of GTR also decreased. Malignant progression may occur after second or third tumor recurrence. Furthermore, compared with WHO grade 1 SFTs, WHO grade 2 and grade 3 SFTs significantly decreased PFS, but OS did not differ among the three groups. Radiotherapy did not prolong PFS or OS in patients who underwent reoperation.

Solitary Fibrous Tumour of the Mesentery: An Uncommon Site for a Rare Tumour.

Solitary fibrous tumour (SFT), a unique spindle-cell neoplasm, was first identified in the pleura and was earlier named as haemangiopericytoma. The origin of SFT is not well established; however, it has recently been described as a mesenchymal neoplasm, probably arising from the ubiquitous dendritic interstitial cells. SFTs are predominantly benign tumours with a low risk of malignant transformation and are commonly seen in the intrathoracic region, seldom involving extrapleural locations. Although SFTs are extensively documented in medical literature, those originating in the mesentery are extremely uncommon. Here, we report an extremely rare case of a 31-year-old woman who presented with abdominal pain and was later diagnosed with SFT of the mesentery of the sigmoid colon based on histomorphology and immunohistochemistry studies. This case highlights that, although uncommon, such differential diagnoses need to be considered in cases of abdominopelvic swellings and must be differentiated from their histological mimickers for better patient care.

Immunological Tumor Microenvironment of Solitary Fibrous Tumors-Associating Immune Infiltrate with Variables of Prognostic Significance.

BACKGROUND AND OBJECTIVES: Solitary fibrous tumors (SFTs) are morphologically heterogeneous tumors characterized by the NAB2::STAT6 gene fusion. Clinical outcomes may vary widely, and while most cases have favorable outcomes, some can progress to aggressive disease, manifesting as recurrence and metastasis, and ultimately resulting in patient death. Herein, we analyze the immunological tumor microenvironment (ITME) of SFTs, aiming to determine its prognostic value and correlation with established risk stratification systems (RSSs). METHODS: A retrospective observational multicenter study of 52 fusion-confirmed SFTs with clinical follow-up data. Immunohistochemical analysis including CD163, CD68, CD3, CD8, CD20, PDL-1, PD-1, and LAG1 were evaluated in tissue microarrays, using an analog scale with scores ranging from 0 to 3 (0 = ≤9, 1 = 10-49, 2 = 50-99, and 3 = >100 positive cells per 10 high-power fields). The expression of these markers was correlated with clinical outcomes, morphological characteristics previously evaluated in whole slide tissue sections (hypercellularity/hypocellularity, round-oval or spindle dominant constituent cell (DCC) morphology, and necrosis), Ki67, overall survival, and RSS. RESULTS: Only one of the fifty-two cases studied showed progression. In the multivariate analysis, neither the presence nor absence of immune cells (B-lymphocytes, T-lymphocytes, and macrophages) showed any association with the assessed RSSs (Demicco, Sugita, G-score, and Huang). Interestingly, the case that showed progression had high immune infiltrate with expression of CD68, CD163, CD8, and CD20 markers (score of 3). Round-oval cell morphology was associated with the presence of higher levels of CD163 macrophages. Lastly, the scant presence of CD20+ lymphocytes correlated with less necrosis, and cases with higher PDL-1 expression correlated with increased Ki67 values. All cases were negative for LAG-1 and PD-1. CONCLUSIONS: SFT ITME components correlated with independent variables with prognostic significance. Nevertheless, ITME did not correlate with RSS scores.

A case of robotic distal pancreatectomy for solitary fibrous tumor of the pancreas.

Solitary fibrous tumor (SFT) is a spindle cell tumor driven by the NAB2-STAT6 fusion gene. While it can originate from any soft tissue, primary SFT of the pancreas is rare with limited reports. A 36-year-old man came to our department due to abdominal pain. Computed tomography revealed a circular mass with weak peripheral enhancement and an internal cyst in the pancreatic tail. Diagnosis was not confirmed through endoscopic ultrasound-guided biopsy, and differential diagnoses included acinar cell carcinoma and pancreatic neuroendocrine tumor. A robotic distal pancreatectomy with splenectomy was performed, and the patient was discharged 11 days postoperatively. 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.

Orbital solitary fibrous tumor.

INTRODUCTION: Solitary fibrous tumor (SFT) is a rare borderline mesenchymal tumor typically arising in the pleura and involving the orbit as its most common extra-pleural location. CASE DESCRIPTION: We herein describe two cases of orbital SFT arising in both a 69-year-old woman presenting with progressive proptosis of the left eye and a 49-year-old woman presenting with binocular diplopia. The diagnoses relied on histopathological analysis of biopsy samples. Because of the poor local prognosis, we decided to perform an orbital exenteration in the first case. In the second case, a complete resection surgery was performed. CONCLUSION: SFT presents classics histological features and immunohistochemical markers that are essential to the diagnosis. SFT is classified as a benign tumor, but in some cases, it can show aggressive behavior with the potential for local tissue invasion and, more scarcely, distant metastasis. This is why complete resection remains the treatment of choice for SFT.