Variable Solitary Fibrous Tumor Locations: CT and MR Imaging Features

An extremely rare case of an isolated primary benign pelvic Solitary Fibrous Tumor in an elderly female

INTRODUCTION AND IMPORTANCE

Solitary Fibrous Tumors are highly rare spindle cell tumors of mesenchymal origin. They comprise <2 % of all types of soft tissue tumors and are characterized by an age-adjusted annual incidence rate of 0.61 per 1 million individuals for extra-meningeal Solitary Fibrous Tumors. The disease course is mostly asymptomatic but can still present with non-specific symptoms. This results in misdiagnosis and delayed treatment. In turn, morbidity and mortality rises and it will constitute a clinical and surgical burden for the affected patients.

CASE PRESENTATION

We present the case of a 67-year-old female who has a known history of controlled hypertension, who presented to our hospital complaining of non-specific pain in her right flank and lower lumbar region. Our preoperative diagnostic radiological workup demonstrated an isolated antero-sacral mass.

CLINICAL DISCUSSION

Comprehensive excision of the mass was laparoscopically achieved. Following the necessary analysis via histopathology and immunohistochemistry, we definitively established the diagnosis of an isolated primary benign Solitary Fibrous Tumor.

CONCLUSION

To the best of our knowledge, no previous cases of SFTs from our country were documented. Clinical suspicion and complete surgical resection are vital determinants in treatment of such patients. Further research and documentation are warranted to set-up the necessary guidelines for preoperative assessment, intraoperative techniques, and adequate follow-up protocols to limit the ensuing morbidity and to detect any possible neoplastic recurrence.

Diagnostic challenges and treatment options in patients with solitary fibrous tumor: A single-center observational study

Introduction

Solitary fibrous tumor (SFT) is an extremely rare disease with a high misdiagnosis rate and a potentially malignant biologic nature. We have collected and analyzed data from 18 SFT patients to provide a deeper insight into this uncommon disease entity.

Methods

In our study, 18 patients who had undergone surgery between April 2014 and December 2021 for the diagnosis of SFT were evaluated. The collected data for each patient included the location of the SFT, the preoperative diagnosis, the definitive histological diagnosis, the presence of postoperative complications, the time of recurrence, the time of systemic progression, the type of treatment, and the survival rate. The median follow-up was 36 months.

Results

In three patients, the preoperative diagnosis did not correlate with the definitive histology of SFT. In patients with the limb location of SFT, no signs of recurrence nor distant metastases were seen within the study period. In total, 50% of the postsurgical complications were associated with the abdominal location of the SFT. In newly diagnosed SFT patients, two patients (20%) developed local recurrence, and the median time until recurrence was 22.5 months. Out of patients that were admitted and operated on for recurrent SFT, 67% relapsed, and the median time to relapse was 9.5 months. The systemic progression of the disease was observed in 33% of patients treated for recurrent SFT.

Conclusion

In our study, the misdiagnosis rate was high and correlated with previously published studies. Postsurgical complications were associated with the extrathoracic location of SFT. The mainstay of SFT treatment remains radical surgery, although radiotherapy alone can significantly improve overall survival. Clinical trials are urgently needed to evaluate the potential effect of other treatment modalities, such as immunotherapy and targeted therapy, in SFT patients.

Magnetic resonance imaging features of a solitary fibrous tumor of the vulva: a case report

Solitary fibrous tumors (SFTs) are commonly seen in the pleura. SFT involvement of the vulva is rare, and clinical diagnosis is mainly based on histopathological and immunohistochemical analyses. We herein describe the imaging features of a 69-year-old woman with an SFT of the vulva. The SFT was hypointense on T1-weighted images, similar to muscle; however, it showed inhomogeneous hyperintensity predominantly on fat-suppressed T2-weighted images. An area of low signal intensity was evident on T2-weighted images, and the tumor showed progressive enhancement in delayed phases. The tumor also displayed heterogeneous and prolonged, persistent enhancement, and serpentine vessels were present in the peritumoral area as signal voids. Pathological examination confirmed that the lesion was an atypical SFT originating from the vulva, and it was composed of spindle cells and perivascular and stromal hyalinization. This case reveals the characteristic imaging findings of vulvar SFT and their association with the relevant pathological findings, thus contributing to the primary diagnosis and preoperative evaluation of this potentially aggressive tumor.

Mesentery solitary fibrous tumor with postoperative recurrence and sarcomatosis: A case report and review of literature

BACKGROUND

Solitary fibrous tumors are rare neoplasms of mesenchymal origin. They are often of low malignant potential and rarely metastasize. They frequently arise from the pleura and can occur at any soft tissue site in the body. However, these tumors rarely develop in the mesentery, peritoneal cavity or peritoneum.

CASE SUMMARY

We report on a scarce case of solitary fibrous tumor of the rectal mesentery showing sarcomatosis about 4 years after previous tumor resection. This 69-year-old male had no clinical symptoms but was transferred to our hospital because of a suspected tumor recurrence from follow-up abdominal computed tomography. Tumor markers (CEA, CA 19-9 and CA 125) were within the normal range. Open laparotomy showed sarcomatosis, and pathology confirmed its mesenchymal origin and diagnosis as the solitary fibrous tumor. Our case may be the second recurrent mesentery solitary fibrous tumor reported to date, and the only one with progression to sarcomatosis. There has been no evidence of recurrence in follow-up at the 28^th mo after extensive intra-operative peritoneal lavage and cytoreductive surgery.

CONCLUSION

Although there are few risk factors of cancer recurrence in this patient, careful long-term follow-up after cytoreductive surgery is necessary.

Solitary fibrous tumors: Clinical and imaging features from head to toe

Solitary fibrous tumors (SFTs) are rare fibroblastic mesenchymal tumors that are usually benign with variable malignant potential. They can develop in any organ due to their spindle cell origin. The exact etiology of solitary fibrous tumors is unknown. The majority of SFTs are benign with 10-30% of them exhibiting aggressive and malignant features. The aggressiveness of this type of tumor is not associated with its histological features, which makes surgical resection the treatment of choice. We will review the clinical and radiological features and possible differential diagnoses of SFTs according to their anatomical sites following the World Health Organization 2020 classification.

Recurrent Solitary Fibrous Tumor in Intradural Extramedullary Space: Case Report and Review of the Literature

Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare neoplasm arising from spindle cells and most commonly arising from pleura. Spinal SFT/HPC is a rare entity; hence, it is not on the top of the differential diagnosis list when a clinician faces a spinal lesion. In the review of the literature, there exist less than 50 case reports of intradural extramedullary SFT/HPC. Here, we present a 54-year-old female patient who underwent subtotal surgical excision of an intradural extramedullary spinal mass pathologically reported to be SFT/HPC and had symptomatic recurrence in the 3^rd year of follow-up. Surgical intervention was unachievable and the patient was given 45 Gy to the surgical cavity followed by a 5.4 Gy boost to visible tumor with external radiotherapy. Patient reported significant relief of her symptoms. We aim to contribute to the formation of a treatment algorithm for this rare entity.

Solitary Fibrous Tumor of the External Auditory Canal

Solitary fibrous tumors (SFTs) originating from the external auditory canal are uncommon; only few cases have been reported in the literature. In this article, we report a case of a 35-year-old man who presented with a 6-month history of a gradual swelling in the entrance of the left external auditory meatus associated with hearing loss. The tumor was surgically removed, and histological examination showed spindle-cell proliferation with a collagenous stroma. Immunohistochemically, the tumor cells were positive for CD34 confirming the diagnosis of an SFT. Although SFTs are benign, complications such as relapses and metastasis after excision were reported. Thus, a careful and long follow-up is recommended.

A Rare Case of Solitary Fibrous Tumour of the Pelvis in an 18-Year-Old Young Man: CT and MRI Features with Pathologic Correlations

Solitary fibrous tumors (SFTs) are mesenchymal neoplasms of fibroblastic origin, even if commonly seen in the pleura, they can occur anywhere in the body. SFT presents as a slow growing, often asymptomatic mass, generally affecting middle-aged adults regardless of the sex. We report a rare case of an 18-year-old man referred to our institution to perform computed tomography (CT) and magnetic resonance imaging (MRI), to investigate a pelvic mass incidentally discovered at abdominal ultrasound examination. A well circumscribed, heterogenous and hypervascular lesion was described at imaging, with absence of calcifications, hemorrhage, necrosis nor cystic degeneration. The mass removal was performed via the Da Vinci-assisted robotic surgery. Histopathological evaluation confirmed the diagnosis of SFT. CT and MRI can aid the identification of SFT, providing useful information which needs to be supported by histopathological analysis.

Clinical management of extrapleural septal solitary fibrous tumor: A case report

Solitary fibrous tumor (SFT) is a rare neoplasm arising from the pleura, although it can sometimes affect extrapleural sites, including the head and neck. The sinonasal involvement is exceptional. Recent literature defines the SFT as a single spectrum of mesenchymal tumors, including hemangiopericytoma, which is currently considered a cellular phenotypic variant. The current case describes a rare case of a nasal septal SFT. The mass was embolized and then removed through endonasal endoscopic surgery. Histopathologic examination demonstrated positive immunoreactivity for CD34, and negative for keratin and S100 protein confirming the diagnosis of benign nasal SFT. After two years of follow-up, no relapse was observed. Diagnostic assessment of SFT requires nasal endoscopy, imaging and histopathological examination and a long time follow up is mandatory.

Solitary fibrous tumor involving urinary bladder: a case report and literature review

Solitary fibrous tumor (SFT) is a rare fibroblast stroma tumor involving the mediastinum and pleura. We herein describe an SFT of bladder which is extremely rare and review 29 similar cases in the last decades. We present a case of a 52-year-old male patient who suffered from urinary urgency and frequency for 12 months. Non-contrast computed tomography (CT) showed a slightly high density calcified mass with 70 mm × 61 mm in diameter. Contrast-enhanced CT demonstrated the mass was slightly enhanced. Cystoscopy revealed a huge mass with flat surface. Histopathological review of the biopsy specimens could not confirm the diagnosis. Partial cystectomy was then performed and the diagnosis of SFT was confirmed by immunohistochemistry. The patient is doing well at 12 months follow-up without recurrence and metastasis. In conclusion, the diagnosis of SFT involving bladder should combine clinical presentation and imaging features. Complete surgical resection is the primary method and long-term follow-up is necessary.

Extremely rare case of intravascular solitary fibrous tumour in the inferior vena cava with review of the literature

BACKGROUND

Solitary fibrous tumour (SFT) is a mesenchymal tumour of fibroblastic type, and it develops in almost any part of the human body. However, according to previous studies, the occurrence of intravascular SFTs is extremely rare.

CASE PRESENTATION

We reported a case of intravascular SFT in a 67-year-old woman who has been experiencing swelling and pain in the right leg for 2 months. Computed tomography venography scan revealed a well-defined mass obstructing the inferior vena cava (IVC). Surgical resection was performed, and histopathologic and immunohistochemical results were consistent with SFT. Further, next-generation sequencing (NGS) analysis was performed, and results revealed two tumour-related gene mutations (deletion of PMS2 and variation of ESR1 [L536P]). The patient did not receive any adjuvant therapy, and no signs of tumour progression were observed during the 6-month follow-up.

CONCLUSION

To the best of our knowledge, this study first presented about SFT arising from the IVC and carried out an NGS analysis to validate the molecular mechanism of such condition.

Inguinal Solitary Fibrous Tumor: A Case Report

INTRODUCTION

A solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm that may occur in a wide range of sites, more commonly in the pleura. We report a well-documented case of an SFT with malignant histology arising in the inguinal region.

CASE PRESENTATION

A 59-year-old man, with an unremarkable medical history, presented with a slow-growing painless mass in the left side of the inguinal region, which he had ignored for 3 years. On clinical examination, there was an indurated, irreducible, mobile, and painless mass in the left side of the inguinal area. Magnetic resonance imaging and computed tomography results revealed a 15-cm mass made up of soft tissue and with nonspecific radiologic aspect. The tumor was totally excised, and the results of the pathologic examination concluded it was an SFT.

DISCUSSION

The aim of our case report is to present a rare extrapleural localization of an SFT. Although its radiologic features are not specific, SFT should be considered in the differential diagnosis of inguinal masses.

Clinicopathological characteristics of renal solitary fibrous tumor: A single institution experience

To analyze the clinical characteristics, treatment modalities and outcomes of adult renal solitary fibrous tumors (SFT) treated at a single institution. Demographic, diagnostic, surgical, and pathological findings of patients who had undergone radical nephrectomy (RN) due to renal SFT were collected from the database of a single institution and were retrospectively reviewed. Ten patients (6 men and 4 women) were diagnosed with renal SFT in our institution between January 1, 2000 and December 31, 2016. The mean age was 50.9 ± 8.2 years (range, 38-63 years). Of the 10 patients, 6 were asymptomatic, 2 presented with flank pain, 1 presented with abdominal discomfort, and 1 presented with haematuria. Computed tomography scans were obtained for all patients. Open RN was performed on 6 patients, and laparoscopic RN was performed on 4 patients. The mean tumor size was 10.23 ± 4 cm (range, 5.3-19 cm). Pathological diagnosis revealed that the tumors in 8 patients were benign, while those in the other 2 patients were malignant renal SFT. No recurrence occurred during a mean follow-up period of 47.3 ± 21.5 months (range, 16-85 months). Renal SFT is extremely rare, and its diagnosis may be challenging because of a lack of typical imaging manifestations. RN is a safe treatment modality for benign or low-grade malignant renal SFT, ensuring favorable outcomes.

Magnetic resonance features of meningeal solitary fibrous tumors

The aim of the present study was to investigate magnetic resonance (MR) features of meningeal solitary fibrous tumors (SFTs) in order to improve their recognition. The study retrospectively analyzed MR manifestations in 12 cases of meningeal SFTs confirmed by surgery. The lesions were analyzed in terms of the site of their growth, growth mode, morphology, size, changes in the MR signal and the edge of the focus. The tumors were malignant in 3 cases, benign in 7 cases and borderline in 2 cases. A total of 3 cases spanned the tentorium cerebelli, 3 spanned the falx and another case was close to the falx. Overall, 4 superficial tumors were accompanied by adjacent bony destruction. One case was located at the triangular area created by the right lateral ventricles. The tumors were all lobular, with a large diameter and more cystic areas in the center of the focus. The signals were often heterogeneous. The parenchyma in the tumors was significantly enhanced. For certain tumors, the signal was usually inhomogeneous and not uniform. The MR features of a SFT were often similar to other intracranial tumors and easily misdiagnosed. There were certain innate characteristics, for example, the tumor was often a solitary large soft-tissue mass with an irregular edge and a clear boundary, with a lobulated contour, and was widely involved with other tissues. The tumors often grew across either the falx or tentorium cerebelli. A significantly inhomogeneous signal was found and either a low or low-high mixed signal on T2-weighted images in particular. These features are useful for the differential diagnosis of SFTs and other tumors.

Solitary fibrous tumor: A clinical case

INTRODUCTION

Solitary fibrous tumor (TFS) is a rare tumor of mesenchymal origin, located mainly in the pleura. It is extraordinarily infrequent find it at the intraespinal level, being the thoracic region the most frequent.

CASE PRESENTATION

We present the case of a 48-year-old patient with progressive ascending lower limb and myelopathy of one month of evolution, with intraspinal location at the D3-D4 level. It was surgically operated by posterior dorsal approach and D3-D4 laminoplasty, with an intradural tumor with an intramedullary component of approximately 18×12mm. The resection was complete and the pathological anatomy gave the diagnosis of solitary fibrous tumor. The patient is currently asymptomatic.

DISCUSSION

Complete tumor resection and histopathological features are the main prognostic factors. Surgery have a main role in this type of neoplasia.

CONCLUSION

There are few case published of solitary fibrous tumor with intraspinal localization. We apport another case to the literature.

Prognostic value of MIB-1 proliferation index in solitary fibrous tumors of the pleura implemented in a new score - a multicenter study

Background

Although the majority of solitary fibrous tumors of the pleura (SFTP) follow a benign course, 10–25% of patients suffer from recurrence or metastatic disease. Several scoring models have been proposed to predict the outcome. However, none of these included immunohistochemical (IHC) markers as possible prognosticators.

Methods

In this multicenter study, we collected clinical data and formalin-fixed and paraffin-embedded (FFPE) tissue blocks of patients with histologically proven SFTP which had been surgically resected between 2000 und 2015. After systematic and extensive IHC staining on tissue microarrays, the results were analyzed and compared to histomorphological and clinical data for their possible prognostic value.

Results

In total, 78 patients (mean age 61 ± 11 years) were included. Of these, 9 patients (11%) had an adverse outcome including SFTP recurrence (n = 6) or SFTP-related death (n = 3). Mean overall survival was 172 ± 13 months. 1 and 10-year event-free survival rates were 99% and 93%. In the multivariable analysis only MIB-1 proliferation index (Ki-67) ≥10% (HR 12.3, CI 1.1–139.5, p = 0.043), ≥4 mitoses per 10 high power fields (HR 36.5, CI 1.2–1103.7, p = 0.039) and tumor size larger than 10 cm (HR 81.8, CI 1.7–4016.8, p = 0.027) were independently associated with adverse outcome.

Conclusion

A high proliferation rate by MIB-1 IHC was associated with impaired outcome. Upon this, we established a new score using mitosis, necrosis, size of the tumor and MIB-1, which performed better than the traditional scores in our data set. This prognostic score could help to better evaluate outcome of SFTP, but requires external validation.

Migrating pleural plaque in a patient with asbestos induced pleural disease: a case report

Background

Health surveillance of formerly asbestos exposed individuals focus on early detection of asbestos related diseases, such as lung fibrosis (asbestosis), pleural plaques, mesothelioma and lung cancer in particular. One main concern is the early and clear identification of lesions with a high risk of malignant changes and their undelayed clinical work-up. False positive results may lead to unnecessary and often painful diagnostic interventions, which create high costs when applied to a large cohort and also may discredit the whole program. We describe an unusual presentation of a common lesion among asbestos exposed individuals, which has to our knowledge never been described before. Being aware of this pathological pathway may prevent inadequate clinical decisions with disadvantages for the patient. Underlying implications regarding health surveillance and the reading of CT-scans of the thorax are important for the management of formerly asbestos exposed individuals.

Case presentation

During follow-up of an asbestos exposed 72 year old former power plant worker with known pleural changes, a nodule located next to the left costophrenic angle was newly discovered on CT-scan. As the previous scan 1 year before did not show any changes in that area, a fast growing tumour was suspected and an immediate biopsy performed. The tissue showed the characteristics of a pleural plaque with no signs of malignancy. After carefully reviewing all previous radiographs a rounded opacity attached to the mediastinal pleura close to the oesophagus and slightly cranial to the position of the removed nodule could be discerned. That nodule had increased in size over several years and was no longer visible on the latest scan. It appeared that the originally slow growing plaque had migrated to the costophrenic angle some time before it was discovered in the latest scan thus imposing as a fast growing tumour.

Conclusions

We concluded that asbestos related pleural plaques can under special circumstances get separated from the pleura and migrate to another position in the pleural cavity. The case provides new insights in the development and properties of pleural lesions and may offer new options for the management of formerly asbestos exposed patients.

Solitary fibrous tumor: A center's experience and an overview of the symptomatology, the diagnostic and therapeutic procedures of this rare tumor

Solitary Fibrous Tumor of the Pleura (SFTP) is a rare tumor of the pleura. Worldwide about 800 patients diagnosed with this oncological entity have been described in the existing literature. We report our center's 13 year experience. During this time three patients suffering from this rare disease have been treated in our department. All patients were asymptomatic and their diagnosis was initially triggered by a random finding in a routine chest x-ray. The diagnosis was set preoperatively through a needle biopsy under computer tomography (CT) guidance. The tumors were resected surgically though video-assisted thoracoscopic surgery (VATS) or thoracotomy. Because of the lack of specific guidelines due to the rarity of the disease a long-term, systematic follow-up was recommended and performed. Parallel an overview of the diagnostic and therapeutic procedures of the rare tumor is made.

Low tissue levels of miR-125b predict malignancy in solitary fibrous tumors of the pleura

Background

Solitary fibrous tumors of the pleura (SFTP) are rare neoplasia of the chest. A subset of SFTP follows a malignant course, sometimes several years after complete resection. Traditional scoring systems based on clinical and histological features are poor predictors of biological behavior. This study aimed to investigate tumor-associated miRNAs expression as novel biomarkers to predict the clinical behavior of SFTP.

Methods

Formalin-fixed and paraffin-embedded SFTP tissues blocks from patients surgically resected between 1992 and 2013 at two tertiary care teaching hospitals were included. SFTP tumors were categorized as either malignant or benign variants according to the WHO classification. Following miRNAs levels were measured: let-7a, miR-16b, miR-17, miR-21, miR-31, miR-34a, miR-92a, miR-125a, miR-125b, miR-195-5b, miR-203a, and miR-223. Differential gene expressions which were calculated with the threshold cycle (C_t) method were compared among the two variants.

Results

Thirty-eight patients (40% male, mean age 62.2 (±10.9) years) were included. Expression levels of miR-125b showed a significant difference between benign compared to malignant variants (−3.08 ± 0.93 vs. -2.22 ± 1.36, p = 0.0068). Furthermore, lower levels of miR-125b were found to be associated with increased tumor size (p = 0.0414). Thus, downregulation of miR-125b indicates malignant transformation. All other investigated miRNAs were not associated with grading of SFTP.

Conclusions

Our data suggest a potential role of miR-125b in the pathogenesis of tumor growth and malignant transformation of SFTP, respectively. Further studies have to address the potential use of miRNA-125b as a biomarker or therapeutic target in SFTP.