Case report: A rare case of malignant solitary fibrous tumor in an adult with an epithelioid pattern in the occipital region.

We illustrated a rare case of malignant solitary fibrous tumor (MSFT) with epithelioid morphology in the occipital region of a 59-year-old female, in which a rare NAB2ex7-STAT6 exon15/16 double fusion subtype was detected by the Next-generation sequencing (NGS) and STAT6 immunohistochemistry (IHC) was diffusely and strongly positively expressed, without recurrence after 20 months of postoperative follow-up. The morphological and molecular genetic aspects and the differential diagnosis are described, and the relevant literature was assessed in order to broaden our understanding and diagnostic capability of this malignancy.

Paraneoplastic hypoglycemia: An overview for optimal clinical guidance.

Paraneoplastic hypoglycemia, also known as non-islet cell tumor hypoglycemia (NICTH), is a rare but critical condition occurring in patients with different types of malignancy. This condition is commonly linked to tumors producing insulin-like growth (IGF) factors, particularly IGF-2 and its precursors, which disrupt glucose homeostasis and lead to excessive glucose consumption. The diagnosis typically involves documenting symptomatic hypoglycemia and ruling out other potential causes. Essential diagnostic tools include imaging studies and laboratory tests, specifically measuring IGF-2 levels and the IGF-2:IGF-1 ratio. Treatment strategies for NICTH are multifaceted and may include surgical resection of the tumor if feasible, pharmacological interventions such as corticosteroids to suppress IGF-2 production, or supportive measures to manage acute hypoglycemic episodes. Novel therapeutic approaches targeting IGF-2, such as monoclonal antibodies or siRNA, are also being explored and hold promise for future treatment options. This review aims to enhance understanding of paraneoplastic hypoglycemia, focusing on its pathogenesis and diagnosis, to guide optimal medical treatment.

Solitary fibrous tumor of the brain: A report of 3 cases.

Solitary fibrous tumor of the central nervous system (CNS) accounts for <1% of all primary CNS tumors. These tumors are typically dura-based and are graded using a three-tiered system based on cellularity, mitotic activity and necrosis. Extracranial metastasis of this disease is rare. The present study reports 3 cases of this rare tumor, retrieved from the hospital archives over a period of 5 years. The hematoxylin and eosin-stained and immunohistochemistry (IHC) slides were reviewed by two pathologists and clinical details were obtained from the hospital records. All 3 cases had tumors located in the cranial cavity. These cases had an outside diagnosis of meningioma, which on re-evaluation at our center (Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India) were found to be solitary fibrous tumor. Of the 3 cases, 1 developed local recurrence and distant metastasis. All cases showed histomorphological features of a spindle cell tumor with positivity for STAT6 by IHC. The genomic NGFI-A-binding protein 2-STAT6 fusion in solitary fibrous tumor leads toSTAT6 nuclear expression on IHC, which confirms the diagnosis and also differentiates it from its close mimics. This case series highlights that histomorphology and IHC are imperative for a correct and timely diagnosis of these tumors, which are commonly misdiagnosed clinically.

Solitary fibrous tumor of the pineal gland: a case report and review of the literature.

Solitary fibrous tumor (SFT) is a type of fibroblastic neoplasm that can occur in various parts of the body, with SFT of the pineal gland being exceedingly rare. We report the case of a 58-year-old male presenting with recurrent hiccups, acid reflux, and headache. Magnetic resonance imaging revealed an occupying lesion in the pineal region, suggestive of a neoplastic process. Intraoperatively, the lesion was located in the pineal region, exhibiting a grayish-red color, and was largely resected. Pathological examination confirmed the diagnosis of solitary fibrous tumor (CNS WHO Grade 1). Postoperatively, the patient was supplemented with radiotherapy, and long-term follow-up showed no signs of recurrence or metastasis.

Advances in the molecular biology of the solitary fibrous tumor and potential impact on clinical applications.

Solitary fibrous tumor (SFT) is a rare fibroblastic mesenchymal neoplasm. The current classification has merged SFT and hemangiopericytoma (HPC) into the same tumor entity, while the risk stratification models have been developed to compensate for clinical prediction. Typically, slow-growing and asymptomatic, SFT can occur in various anatomical sites, most commonly in the pleura. Histologically, SFT consists of spindle to oval cells with minimal patterned growth, surrounded by stromal collagen and unique vascular patterns. Molecularly, SFT is defined by the fusion of NGFI-A-binding protein 2 (NAB2) and signal transducer and activator of transcription 6 (STAT6) genes as NAB2-STAT6. This fusion transforms NAB2 into a transcriptional activator, activating early growth response 1 (EGR1) and contributing to SFT pathogenesis and development. There are several fusion variants of NAB2-STAT6 in tumor tissues, with the most frequent ones being NAB2ex4-STAT6ex2 and NAB2ex6-STAT6ex16/ex17. Diagnostic methods play a crucial role in SFT clinical practice and basic research, including RT-PCR, next-generation sequencing (NGS), FISH, immunohistochemistry (IHC), and Western blot analysis, each with distinct capabilities and limitations. Traditional treatment strategies of SFT encompass surgical resection, radiation therapy, and chemotherapy, while emerging management regimes include antiangiogenic agents, immunotherapy, RNA-targeting technologies, and potential targeted drugs. This review provides an update on SFT's clinical and molecular aspects, diagnostic methods, and potential therapies.

Doege-Potter syndrome due to a solitary fibrous tumor of the pleura: a case report.

BACKGROUND: Doege-Potter syndrome is a rare paraneoplastic phenomenon associated with solitary fibrous tumors of the pleura (SFTPs). It is characterized by the presence of severe, sustained, and treatment-refractory hypoglycemia. Hypoglycaemia, which may be the sole symptom at disease onset, is mediated by the secretion of high-molecular-weight insulin-like growth factor (IGF-2). Most tumors exhibit benign behavior, with a 100% survival rate at 5 years. However, 10% of these tumors may display aggressive behavior with local or metastatic recurrence. We present a clinical case of a patient with a benign solitary fibrous tumor of the pleura who presented with symptomatic hypoglycemia and required pulmonary and pleural surgical resection to control the paraneoplastic phenomenon. CASE PRESENTATION: A Hispanic 46-year-old man presented with a 15-day history of transient alterations in consciousness worsened by fasting. The relevant medical history included obstructive sleep apnea treated with continuous positive air pressure (CPAP) and previous smoking. In-hospital studies revealed noninsulinemic hypoglycemia and a benign SFTP. Complete surgical resection was performed while the patient received dextrose fluids and corticosteroids perioperatively for hypoglycemia. Subsequently, the hypoglycemia resolved, and the patient was followed-up without disease recurrence. CONCLUSION: Doege-Potter syndrome is challenging to recognize. However, effective treatment can be achieved with a high survival rate. Raising awareness among healthcare professionals about the recognition of this paraneoplasic syndrome patients will improve diagnostic suspicion, biochemical confirmation, the development of diagnostic and therapeutic guidelines, and the creation of predictive indices for aggressive presentations requiring closer monitoring.

Solitary fibrous tumor of the Pelvic cavity: A rare entity with review of literature.

Solitary fibrous tumor (SFT) arising from adult mesenchymal stem cells is an uncommon vascular tumor of pelvic cavity. While initially thought to be confined to the pleura, pericardium, or peritoneum, recent studies have revealed that SFTs can develop in different areas of the body. Typically, SFTs grow slowly and may not present noticeable symptoms. In this 2 case study, we describe the clinical situation of a 46-year-old female patient and 68 years old male patient who complained of persistent pelvic pain and urinary symptoms respectively. Imaging tests revealed solitary fibrous tumor in the pelvic cavity which was confirmed on histopathology, an unusual location for this type of tumor. This case reports focusses on importance of early recognition and treatment in dealing with this rare tumor.

Case report: Solitary fibrous tumor of the paracervical uterus combined with vaginal wall adenocarcinoma.

Background: Solitary fibrous tumors are rare mesenchymal tumors that typically occur in the pleura. Solitary fibrous tumors of the uterine cervix are uncommon. We report the first case of a patient who underwent total hysterectomy for vaginal wall adenocarcinoma and was found to have a concurrent solitary fibrous tumor in the paracervical-uterus. Case presentation: A 51-year-old woman was admitted to our hospital due to contact bleeding. A gynecological examination revealed nodules of 3.0 × 1.0 cm on the vaginal wall, and a colposcopy with biopsy revealed adenocarcinoma of the vaginal wall. After the recommended staging examinations, the patient underwent total hysterectomy, double adnexectomy, pelvic lymph node dissection, and vaginal wall resection. During surgery, a nodule measuring approximately 2 × 2 cm was found in the middle of the mass in the left paracervical region. Subsequent postoperative histopathological examination confirmed an solitary fibrous tumor of the uterine cervix with adenocarcinoma of the vaginal wall. The patient was followed up for 46 months after hospitalization, and no recurrence or distant metastases were observed. Conclusion: In rare cases, solitary fibrous tumors may form large masses in the cervical or vaginal wall. They can easily be misdiagnosed as benign or malignant cervical tumors before and during surgery. Postoperative pathology and immunohistochemistry are helpful for diagnosis. Most solitary fibrous cervical tumors are benign, occasionally with low malignant potential, and surgical treatment is feasible and effective.

Meningeal solitary fibrous tumor cell states phenocopy cerebral vascular development and homeostasis.

BACKGROUND: Meningeal solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that are associated with local recurrence and hematogenous metastasis. The cell states and spatial transcriptomic architecture underlying the unique clinical behavior of meningeal SFTs are unknown. METHODS: Single-cell (n=4), spatial (n=8), and bulk RNA sequencing (n=22) was used to define the cell states and spatial transcriptomic architecture of meningeal SFTs across histological grades and in patient-matched pairs of primary/recurrent or intracranial/metastatic samples. Immunofluorescence, immunohistochemistry, and comparison of single-cell types to meningiomas, or to cerebral vascular development or homeostasis, were used for validation. RESULTS: Here we show meningeal SFTs are comprised of regionally distinct gene expression programs that resemble cerebral vascular development or homeostasis. Single-cell trajectory analysis and pseudotemporal ordering of single-cells suggest that meningeal SFT cell fate decisions are dynamic and interchangeable. Cell-cell communication analyses demonstrate receptor-ligand interactions throughout the meningeal SFT microenvironment, particularly between SFT cells, endothelia, and immature neurons. Direct comparison of single-cell transcriptomes from meningeal SFTs versus meningiomas shows that SFT cells are enriched in expression of endothelial markers while meningiomas cells are enriched in expression of mural cells markers. Meningeal SFT spatial transcriptomes show regionally distinct intratumor heterogeneity in cell states, gene expression programs, and cell-cell interactions across WHO histological grades and in patient-matched pairs of primary/recurrent or intracranial/metastatic samples. CONCLUSIONS: These results shed light on pathways underlying meningeal SFT biology in comparison to other central nervous system tumors and provide a framework for integrating single-cell, spatial, and bulk RNA sequencing data across human cancers and normal tissues.

Surgical management of giant solitary fibrous tumors of the pleura: Two case reports.

INTRODUCTION: Solitary fibrous tumor of the pleura (SFTP) is a rare primary tumor originating from mesenchymal cells located beneath the mesothelial-lined pleura. A special entity is the giant SFTP which presents unique challenges in surgical management. CASE PRESENTATION: Two cases of giant SFTPs in middle-aged patients are presented. Both patients presented with a recent worsening dyspnea and had imaging findings consistent with giant masses occupying the entire pleural cavity with a complete collapse of the homolateral lung and substantial contralateral deviation of heart and mediastinum. The pathological results of CT-guided transthoracic core needle biopsy was SFTP in both cases. Surgical resection was performed, and they both required two thoracotomies for complete tumor removal. Successful complete en bloc resection of the tumors was achieved with a total postoperative recovery. The first resected tumor was 30 × 20 cm and weighed 3500 g, the second was 33*x25 cm in size and weighed 4000 g. Both patients respiratory condition improved after the operation and no recurrence were noted in the follow-up. DISCUSSION: SFTPs are removed using various approaches: thoracotomy, sternotomy with the possibility of hemiclamshell extension, video-assisted thoracoscopic surgery (VATS), and robotic-assisted surgery. The challenge when operating giant SFTP (> 15 cm) is double: adhesions and compression to the lung tissue and surrounding mediastinal structures and the hyper vascular nature of the tumor. For giant SFTPs an open approach is preferable. Resection should be complete with negative margins due to the high risk of recurrence. CONCLUSION: These cases emphasize the significance of personalized surgical strategies for managing giant SFTPs, providing valuable insights for clinicians addressing similar cases.

Rare Cerebral Location of a Left Lateral Ventricle Solitary Fibrous Tumor (SFT): A Case Report With Literature Review.

Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that can occur intraventricularly, presenting diagnostic and management challenges. We describe a case of a 21-year-old male with no significant medical history who presented with intermittent headaches and vomiting, progressing to continuous symptoms. Neurological examination was unremarkable. Brain MRI revealed an isointense lesion in the occipital horn of the left lateral ventricle, diagnosed as an SFT. Surgical excision via a transcortical approach was successful, followed by postoperative radiotherapy. This case highlights the complexities in diagnosing and treating intraventricular SFTs, emphasizing the need for comprehensive evaluation and multimodal management strategies.

CD34-Negative Malignant Renal Solitary Fibrous Tumor: Case Report and Diagnostic Insights.

Solitary fibrous tumors (SFTs) are rare fibroblastic neoplasms with diverse biological behaviors and widespread distribution. Primary renal SFTs are uncommon, and their malignant variants, especially those that are CD34 negative, are even rarer. This study presents a case of malignant renal SFT in a 57-year-old female, focusing on its immunomorphological features. On gross examination, the tumor's large size (11.5 cm) was remarkable. Microscopic analysis showed high cellularity, diffuse sheets of moderately pleomorphic ovoid cells, prominent staghorn vessels, tumor cell necrosis, and a high mitotic count. Immunohistochemistry revealed strong positivity for STAT6, vimentin, and Bcl-2 and, notably, negativity for CD34. The presence of the NAB2::STAT6 gene fusion was confirmed through fluorescence in situ hybridization. This case emphasizes the need to consider SFT in the differential diagnosis of unusual renal tumors, even when CD34 is negative. The infrequency, morphological diversity, and resemblance to other tumors make diagnosing renal SFTs challenging. Accurate identification and classification as benign or malignant are crucial for proper clinical management and prognosis.

Case report: A huge retroperitoneal solitary fibrous tumor closely related to the external iliac vessels misdiagnosed as an ovarian tumor.

Background: Solitary fibrous tumor (SFT) is a rare soft tissue tumor originating from mesenchymal cells. Thus far, there have been no reported cases of SFT closely related to the iliac vessels. Case presentation: An elderly woman was found to have had a lower abdominal mass for more than 20 years. The enhanced computerized tomography (CT) showed a progressively enhanced hypervascular mass. The external iliac blood vessels were closely related to the mass, which was misdiagnosed as an ovarian tumor. During laparotomy, the external iliac vein was seen to penetrate the tumor, and the external iliac artery was seen to penetrate the tumor capsule. The retroperitoneal tumor was diagnosed during the operation. The surgical plan of complete tumor resection, severing of the external iliac arteries and veins, and blood vessel replacement was implemented. Pathological immunohistochemistry showed positive results for STAT6 and CD34, confirming the diagnosis of giant retroperitoneal SFT. The risk is classified as high and requires long-term follow-up. There has been no local recurrence or distant metastasis almost 1 year after surgery. Conclusion: The incidence of giant retroperitoneal SFT is rare, and the diagnosis can be confirmed through preoperative imaging examination and pathological examination. If the SFT capsule is intact, there is a chance of surgical resection. For SFTs that are penetrated by the iliac blood vessels, adequate preparation must be made before the surgery is performed. Removing the tumor and the iliac blood vessels at the corresponding site and then replacing it with artificial blood vessels is a feasible method with less risk of bleeding. In this case, imaging showed a progressively enhancing hypervascular mass in the lower abdomen, which was related to blood vessels. Preoperative biopsy and pathological testing can confirm the diagnosis. Neoadjuvant therapy or interventional therapy before surgery can shrink the tumor, making the surgical procedure relatively easy with less risk of bleeding.

Excision of a Solitary Fibrous Tumor in the Sciatic Notch with Sciatic Nerve Compression - A Rare Clinical Case.

We present the clinical case of a 41-year-old woman with no relevant personal history. The patient complained of diffuse self-limiting abdominal pain, and we incidentally detected an extra-abdominal, extraperitoneal tumor mass at the level of the right sciatic notch. The abdominal complaints were gone during the initial follow-up, but the patient developed sciatica radiating to the right foot and electric shock-like pain. A computed tomography (CT)-guided biopsy revealed a low-grade mesenchymal neoplasm of the soft tissues with characteristics consistent with a solitary extrapleural fibrous tumor. The pelvis team of the orthopedics department received the patient for surgical excision of the lesion. The procedure occurred with no complications, and we excised the totality of the lesion with tumor-free margins. An anatomopathological examination was compatible with the biopsy assessment. The excision of the lesion resulted in complete resolution of the sciatic nerve compression-related symptoms.

Intracranial solitary fibrous tumors: Clinical, radiological, and histopathological insights along with review of literature.

BACKGROUND: Intracranial solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms, often challenging to diagnose due to their resemblance to meningiomas and other central nervous system tumors. While advancements in molecular genetics have aided in classification, diagnostic nuances and optimal management strategies remain areas of interest. MATERIALS AND METHODS: This retrospective study analyzed 11 cases of intracranial SFTs treated at a neurosurgical centre in India between February 2020 and January 2024. Clinical data, radiological findings, histopathological features, and follow-up details were reviewed. Immunohistochemistry, particularly STAT6, facilitated diagnosis confirmation. RESULTS: The median age of presentation was 32 years, with a male predominance. Headache was the most common presenting symptom, often leading to misdiagnosis as meningiomas on radiological imaging. Histologically, SFTs exhibited spindle to ovoid cells with staghorn vessels and collagenized stroma, posing challenges in differential diagnosis. WHO grading predominantly revealed grade 1 tumors, though recurrence occurred, emphasizing the importance of long-term follow-up. Immunohistochemistry, particularly STAT6, played a pivotal role in distinguishing SFTs from other entities. CONCLUSION: Intracranial SFTs present diagnostic challenges due to overlapping features with other tumors, warranting a comprehensive approach integrating clinical, radiological, and histopathological findings. Immunohistochemistry, particularly STAT6, emerges as a valuable diagnostic tool. Long-term follow-up is essential for monitoring recurrence and potential malignant transformation. Further research is needed to delineate optimal treatment strategies, including the role of radiotherapy in SFT management.

Resection and postoperative pazopanib for intraspinal recurrent solitary fibrous tumor: illustrative case.

BACKGROUND: Intracranial solitary fibrous tumors (SFTs) rarely recur in the spinal space. Only 4 cases of spinal recurrence from intracranial SFT have been reported; therefore, the optimal treatment of recurrent spinal SFT remains unclear. OBSERVATIONS: A 53-year-old woman with a history of resection of a right occipital anaplastic SFT presented with progressive back and side pain. She was diagnosed with an intradural extramedullary tumor ventral to the spinal cord at the T5-7 level. She underwent tumor resection with T5-6 laminectomy and T4 and T7 partial laminectomy. The tumor was completely removed in a piecemeal fashion using an ultrasonic aspirator with careful control of bleeding. Her symptoms quickly improved after the surgery, and she returned to normal life. The tumor was diagnosed as SFT. Pazopanib was administered postoperatively. Despite the recurrence of the intracranial tumor, the patient was alive without recurrence of the spinal tumor 14 months after resection. LESSONS: Although rare, intracranial SFTs have a risk of spinal recurrence. Complete resection of a recurrent spinal SFT can be achieved even in the ventral location. Pazopanib could be a possible therapeutic option for preventing local tumor recurrence in the management of recurrent spinal SFT. https://thejns.org/doi/10.3171/CASE24217.

Recurrent Hypoglycemia in a Non-diabetic Female: A Case Study on Doege-Potter Syndrome.

Solitary fibrous tumors (SFT) are mesenchymal cell tumors that may arise from any site throughout the body. A small percentage of patients with SFT develop non-islet cell tumor-induced hypoglycemia (NICTH), eponymously termed Doege-Potter Syndrome (DPS). DPS is characterized by severe, refractory hypoinsulinemic hypoglycemia. Diagnosis of SFT is dependent on histologic findings and immunohistochemistry (IHC). NAB2-STAT6 gene fusions are pathognomonic for SFT but may be difficult to identify in routine cytogenetic studies. STAT6 IHC is a highly sensitive and specific surrogate for the NAB2-STAT6 gene fusion. Total resection of the tumor remains the gold-standard definitive treatment of SFT of the pleura. Palliative tumor debulking is recommended if total resection is not feasible. We here report a case of DPS in a 73-year-old female, managed with palliative care.

Giant solitary fibrous tumor of the olfactory groove. An unusual simulator in an unusual location.

Solitary fibrous tumors are rare mesenchymal neoplasms that can develop in any part of the body, with those that settle intracranially being confused with meningiomas as a general rule. We present the case of a 57-year-old man referred to our hospital due to bifrontal headache, anosmia, and behavioral alterations of 6 months' duration. Radiological studies revealed the existence of a large tumor mass with an extra-axial appearance and location in the anterior cranial fossa, initially compatible with a giant meningioma of the olfactory groove. Gross total resection of the mass was carried out. The pathological diagnosis was unexpected: a solitary fibrous tumor (WHO grade 1, 2021). Given the aggressive nature of these lesions, with a tendency to recurrence, malignant transformation and even metastasis, surgery with macroscopically complete resection intention should constitute the first therapeutic option. Close clinical-radiological follow-up after the procedure is justified.