Solitary Fibrous Tumors of the Pleura: Surgical Outcome and Clinical Course

Giant intrapulmonary solitary fibrous tumor with signs of malignancy

Solitary fibrous tumor (SFT) is an extremely rare mesenchymal neoplasm usually detected in the pleura, which generally follows a benign course. The localization inside lung parenchyma has more rarely been reported. We present a case of a 51-year-old male with a dry cough, dyspnea, chest pain, and increased perspiration. Radiological images revealed a giant circumscribed mass on the right side of the chest. A transbronchial cryobiopsy of the lung was performed and revealed an SFT. The right upper lobectomy through lateral thoracotomy was performed. The pathological examination confirmed an SFT with a central zone of necrosis that is a sign of malignancy. At a 2-year follow-up, the patient is free of symptoms and with no evidence of recurrence. Although the intrapulmonary localization of an SFT is a rare entity, we should be aware of it as a potential malignant pulmonary neoplasm.

Surgical removal of an unusual huge solitary fibrous tumor in the mediastinum: a case report

BACKGROUND

Intrathoracic Solitary Fibrous Tumors (SFT) mainly arise from the pleura; however, these tumors may also originate from the mediastinum. We present a rare case of posterior SFT extending to several mediastinal sites and with an unusual large size, successfully treated with surgical resection.

CASE PRESENTATION

A 66-year-old female presented with an initial manifestation of ambiguous pain in the chest and dysphagia and later developed pitting edema in both lower extremities and cachexia five months before admission. Chest imaging confirmed a mediastinal mass (17 × 15 × 8 cm) which was surgically removed. Immunohistochemistry confirmed the diagnosis of a solitary fibrous tumor with positive B-cell lymphoma 2, STAT6, and CD99, negative S100 and smooth muscle actin, and low levels of Ki67 (5-7%). The patient's follow-up course was unremarkable.

CONCLUSION

Mediastinal SFTs may grow extremely huge, with the potential to invade multiple adjacent sites. Surgical removal of the tumor remains the mainstay of treatment in these cases.

Surgery for Solitary Fibrous Tumors of the Pleura: A Review of the Available Evidence

Solitary fibrous tumors of the pleura (pSFT) are a relatively rare neoplasms that can arise from either visceral or parietal pleura and may have different aggressive biological behaviors. Surgery is well known to be the cornerstone of the treatment for pSFT. We reviewed the existing literature, focusing on the role of surgery in the management and treatment of pSFT. All English-written literature has been reviewed, focusing on those reporting on the perioperative management and postoperative outcomes. Surgery for pSFT is feasible and safe in all experiences reported in the literature, but surgical approaches and techniques may vary according to the tumor dimensions, localization, and surgeons' skills. Long-term outcomes are good, with a 10-year overall survival rate of more than 70% in most of the reported experiences; on the other hand, recurrence may happen in up to 17% of cases, which occurs mainly in the first two years after surgery, but case reports suggest the need for a longer follow-up to assess the risk of late recurrence. Malignant histology and dimensions are the most recognized risk factors for recurrence. Recurrence might be operated on in select patients. Surgery is the treatment of choice in pSFT, but a radical resection and a careful postoperative follow-up should be carried out.

Multiple solitary fibrous tumors of the pleura with multicentric and unilateral involvement: a case report

BACKGROUND

Solitary fibrous tumor of the pleura (SFTP) is a mesenchymal tumor. Patients with SFTP generally have only one lesion. We herein report an extremely rare case of multiple SFTPs that were multicentric and unilateral.

CASE PRESENTATION

The patient was a 21-year-old asymptomatic young man who was referred to our hospital due to abnormal shadows on a chest X-ray. Computed tomography showed 6 tumors of heterogeneous sizes in the left thoracic cavity. The tumors were suspected to be multiple benign or low-grade malignant thoracic tumors, and tumor resection was performed. The tumors had almost the same appearance, with uniform fibroblastic spindle cell proliferation, and arose from the pleura in microscopy. Immunohistochemical staining revealed that the tumor cells were positive for CD34, CD99, Bcl-2, and STAT6. Based on these findings, the tumors were diagnosed as multiple SFTPs with multicentricity. At 1 year and 6 months after the first surgery, 2 new lesions were found above the diaphragm, and these were resected. These tumors were arose from the pleura with a fibrous capsule structure. Their pathological findings were identical to the initial tumor without evidence of malignant transformation.

CONCLUSION

We experienced an extremely rare case of multiple SFTPs with multicentric and unilateral lesions.

A case report and literature review on primary solitary fibrous tumor of the bladder

RATIONALE

Solitary fibrous tumors (SFT) is a rare mesenchymal tumor originating from a CD34-positive dendritic mesenchymal cell, most of which is benign, the most common sites is pleura and mediastinum, and rarely in the bladder. The clinical manifestations are mainly related to the tumor volume. When the tumor volume is large, it will compress the surrounding tissues or organs and cause corresponding symptoms. Laparoscopic Incision biopsy is effective means for diagnosing SFT.

PATIENT CONCERNS

A 70-year-old female patient was admitted to the hospital with a bladder neoplasm detected by computed tomography scan after experiencing intestinal obstruction 3 days following esophageal cancer surgery. She denied any history of tumor disease.

DIAGNOSES

No abnormality was found in the physical examination and laboratory testing after admission. Ultrasound imaging showed a large solid mass with low echogenicity in the bladder. Urological computed tomography with 3D reconstruction revealed a large cystic-solid mass located on the right wall of the bladder, measuring approximately 6.8 cm × 7.1 cm × 6.5 cm, with uneven density and mild inhomogeneous enhancement after contrast administration. Cystoscopy revealed a large mucosal bulge on the right wall of the bladder and laparoscopic exploration revealed a smooth-surfaced round mass, approximately 7 cm in size.

INTERVENTIONS

Incision biopsy was performed to make a clear diagnosis, and appropriate tissue specimens were obtained for pathological testing.

OUTCOMES

The patient was diagnosed as SFT according to pathology. The patient was followed up for 6 months after surgery, and no recurrence was observed.

LESSONS

SFT occurring in the bladder are extremely rare, and the site is scarcely reported in the relevant literature; thus, it is easy to misdiagnose and laparoscopic incision biopsy may be a good choice.

Surgical considerations in the resection of solitary fibrous tumors of the pleura

Solitary fibrous tumors (SFTs) are rare mesenchymal pleural neoplasms with an overall good prognosis and low recurrence rate if completely resected and if degree of differentiation is favorable. Within the last decade, advances in research have led to more reliable methods of differentiating SFTs from other soft tissue tumors. Historically, several markers were used to distinguish SFTs from similar tumors, but these markers had poor specificity. Recent evidence showed NAB2-STAT6 fusion gene to be a distinct feature of SFTs with 100% specificity and sensitivity. Surgical resection, with an emphasis on obtaining negative margins, is the mainstay of treatment for SFTs. Preoperative planning with detailed imaging is imperative to delineate the extent of disease and vascular supply. One important radiologic distinction to aid delineation of a pleural-based tumor compared to a pulmonary parenchymal-based tumor is the angle that the tumor forms with the chest wall, which is obtuse for a pleural-based tumor, and acute for tumors of the lung parenchyma. Often, preoperative tissue diagnosis is not available, and surgery is both diagnostic and curative. Intraoperatively, emphasis should be on complete resection with negative margins. SFTs are resected via several approaches: thoracotomy, sternotomy with the option of hemi-clamshell extension, video-assisted thoracoscopic surgery, and robotic approach, which is increasingly being used and is our preference. We recommend a minimally invasive approach for most lesions, and have resected SFTs of the pleura that are up to 12 cm with the robotic approach. However, the current literature often cites 5 cm as the cut off for an open thoracotomy. Nevertheless, even with larger tumors, a minimally invasive robotic approach is our preference and practice. For giant SFTs (> 20 cm), an open approach may be preferable. Multiple thoracotomies and rib resection may be required to gain adequate exposure and ensure complete resection in these tumors. However, it is noteworthy that most of these tumors have a soft consistency and thus, once bagged, can easily be removed minimally invasively, and thus minimally invasive approach should not be completely ruled out. Recurrence in SFTs usually results from incomplete resection and redo surgery may portend a favorable prognosis.

Malignant Solitary Fibrous Tumours of the Pleura Are Not All the Same: Analysis of Long-Term Outcomes and Evaluation of Risk Stratification Models in a Large Single-Centre Series

Introduction: Malignant solitary fibrous tumours of the pleura (mSFTP) are extremely rare diseases (<5% of all pleural neoplasms) with unpredictable behaviour. Surgery remains the standard of care for these tumours; however, estimating patient prognosis and planning follow-up remain challenging. Several risk stratification models have been proposed, but a classification with diagnostic and prognostic potential has not been well standardised yet. The aim of this study was to analyse the clinicopathological data of mSFTP to investigate their prognostic features and to compare the performance of three risk stratification models proposed in the literature. Methods: Observational retrospective cohort study on all proven cases of mSFTP surgically resected with radical intent between 2000 and 2019 in a single centre. Demographic, surgical and pathological data were examined. All patients were risk-stratified by using three prediction models: modified Demicco, De Perrot and Tapias. Overall survival (OS) and disease-free survival (DFS) were analysed. Results: There were 21 men and 13 women (median age, 67 years, range, 23-83 years). Twenty-one patients (62%) were symptomatic. The median follow-up was 111 months (range, 6-258 months). The 5-year OS and DFS were 81.2% and 77.4%, respectively. Nine patients (26.5%) experimented recurrences. At univariate analysis, the presence of necrosis (p = 0.019), nuclear atypia (p = 0.006), dimension greater than 11.5 cm (median value of our cohort) (p = 0.037) and relapse/disease progression (p = 0.001) were independent prognostic factor of worse OS. The administration of adjuvant treatment was a protective independent factor for survival (p = 0.001). Radicality of resection (p = 0.005); tumour dimension (p = 0.013), presence of necrosis (p = 0.041) and nuclear atypia (p = 0.007) and pleural pattern (p = 0.011) were independent prognostic factors of worse DFS. Analysing the three risk stratification models, the Tapias score was revealed as the best index to predict both OS (p = 0.002) and DFS (p = 0.047) in patients with mSFTP. Conclusions: Using the risk stratification model proposed by Tapias, patients with the highest risk of recurrence could be identified at the time of surgery to establish a more frequent imaging surveillance and longer follow-up. The role of adjuvant treatment in mSFTP therapy has not been established yet, but further analysis on patients with a high risk of recurrence, stratified according to risk models, along with biomolecular panels may tailor future post-surgical therapies.

Toward Better Understanding and Management of Solitary Fibrous Tumor

Solitary fibrous tumor (SFT) comprises a histologic spectrum of soft tissue neoplasms that are characterized by the unique NAB2-STAT6 gene fusion. Changes in diagnostic terminology and site-specific classification over the past few decades have resulted in a disjointed literature. Complete surgical excision with preservation of function remains the mainstay of treatment. New risk stratification systems including risk factors such as mitotic rate, age, tumor size, and presence of necrosis, among others, can be used to predict risk of recurrence or metastasis. Long-term follow-up after surgical resection is recommended. The clinical manifestations, diagnosis, management, and prognosis of SFT are reviewed here.

Malignant solitary fibrous tumor of the pleura

Background

Solitary fibrous tumors of the pleura are rare diseases of the thoracic cavity. They frequently grow unnoticed until they exert compressive effects on adjacent organs. Treatment of solitary fibrous tumors of the pleura is surgical resection. Post-operative surveillance is recommended to identify early recurrent disease.

Case presentation

We present a rare case of a 76-year-old female patient with no previous pulmonary history who presented with progressive dyspnea, fatigue, and involuntary weight loss. On chest X-ray and computed chest tomography scan, she was found to have a 16.7 cm × 12.8 cm × 10.1 cm bulky mass occupying the left hemithorax with associated compressive atelectasis of the lung. She underwent a computed tomography guided biopsy that revealed the mass to be a solitary fibrous tumor. The patient underwent left muscle sparing lateral thoracotomy with complete resection of the tumor. Post procedure, the left lung fully expanded. 18 months post-resection, she developed a 3.3 cm × 1.7 cm tumor along the left internal thoracic artery lymph node chain which was histologically identical to the resected tumor. The patient is currently being treated with bevacizumab and temozolomide.

Conclusion

Solitary fibrous tumors are very rare pleural tumors. Surgical resection is the treatment of choice followed by close post-operative surveillance.

Surgical and radiation treatment of a paravertebral malignant solitary fibrous tumor: a case report and literature review

Malignant solitary fibrous tumors (MSFT) are rare neoplasms, and typically exhibit an aggressive course. While complete surgical resection is the primary treatment modality, the role of adjuvant radiation treatment in larger tumors is not well-established. Despite limited reported cases which demonstrated extended disease-free periods with adjuvant radiation, its utilization is conflictingly both recommended or discouraged across the literature due to the absence of high-quality published data. This is a report to add to the slowly growing body of literature to support the use of adjuvant radiation in these tumors. Specifically, a case of a 64-year-old man who developed rash and mild back pain after a total hip arthroplasty. He was found to have a large paravertebral MSFT, and was treated with surgical resection followed by adjuvant radiation due to size and focally positive margins. He has continued to have no evidence of disease 21 months after treatment. This case of successful treatment and continued disease-free interval with resection and adjuvant radiation contributes valuable supporting data to the management of this rare disease entity. Furthermore, a review of available literature on MSFT treatment is conducted to illustrate the inconsistency in post-surgical management, and demonstrate the necessity of additional detailed reports from a radiation treatment perspective.

[Monstrous Solitary Fibrous Tumor of the Pleura - A Case Report and Review of the Literature]

Localized solitary fibrous tumors are a rare entity and are mostly found in the thorax, but can also occur in the liver, skin, meninges, peritoneum, and pericardium. Making the diagnosis is often difficult because of the various micromorphologic outlooks. The histopathological assessment with differentiated immunohistochemistry is decisive. Surgical resection of the localized solitary fibrous tumors is the therapy of choice. The recurrence and metastasis rates depend on the histological dignity and are in total very low. Therefore, continuous follow-up examinations are indicated. We report on a 76-year-old female patient with a monstrous solitary fibrous tumor of the pleura who complained of exertional dyspnea and sharp pain in the right thoracic region for several weeks. Computed tomography showed a massive, heterogeneous pulmonary mass 22 cm in diameter in the middle and lower field of the right lung with compression of the diaphragm and mediastinum. The tumor was completely resected through a double thoracotomy in the 5th and 8th ICR. Intraoperatively, the tumor was stalked to the middle lobe. In order to completely remove the tumor, a wedge resection was also performed from the middle lobe. The tumor weighed 2.4 kg. The diagnosis of a solitary fibrous tumor of the pleura was made histologically and immunohistochemically. Postoperatively, the lung has fully expanded. There was no evidence of a relapse at the 3-month follow-up examination. The clinical symptoms, diagnosis, treatment options, risk of recurrence and the prognosis of these tumors are shown and discussed in accordance with the literature.

Recurrent solitary fibrous tumor of the pleura with malignant transformation: a case report

We report a rare case of recurrent solitary fibrous tumor (SFT) of the pleura with suspicious malignant transformation. A 78-year-old man had undergone prior surgical resection of the primary and recurrent SFT tumors at 11 and 2 years before the current presentation. Although his primary tumor had a round shape and did not show invasive growth, the current recurrent tumor extended through the neural foramen and had an osteoclastic progression into the thoracic spine. A computed tomography (CT) guided needle biopsy was performed and the pathological diagnosis of the tumor was confirmed as the recurrence of SFT. Immunohistochemically, the MIB-1 proliferation index (Ki-67) of the primary tumor and the current tumor was 1.74 and 30.00%, respectively. These clinical and immunohistochemical findings were strongly suspected the malignant transformation of SFT from benign. He was treated with radiotherapy, and a response was observed.

Recurrence rates of surgically resected solitary fibrous tumours of the pleura: a systematic review and meta-analysis

OBJECTIVES

Recurrence rates of solitary fibrous tumours of the pleura (SFTP) after surgical resection vary widely in the published literature. Our objective was to systematically review the existing literature to determine an accurate estimate of SFTP recurrence rates after surgical resection and to determine risk factors associated with recurrence.

METHODS

PubMed, EMBASE and the Cochrane library were systematically searched for randomized controlled trials and observational studies (prospective or retrospective) through 20 June 2020 that reported the recurrence rates after surgical resection. The outcome of interest was recurrence.

RESULTS

Of the 23 included studies comparing 1262 patients, the overall recurrence of SFTP in patients who underwent surgical resection was 9% [95% confidence interval (CI) 7-12%; I2 = 52%]. In addition, pooled benign and malignant recurrence rates were 3% (95% CI 2-5%; I2 = 8%) and 22% (95% CI 15-32%; I2 = 52%), respectively. A benign SFTP was associated with a significantly lower recurrence rate than a malignant SFTP [odds ratio (OR) 0.11; 95% CI 0.06-0.20; I2 = 0%]. There was no significant difference in the recurrence rates between lesions originating from parietal versus visceral pleura (OR 1.30; 95% CI 0.28-6.02; I2 = 59%). Female sex was associated with increased recurrence (OR 5.29; 95% CI 1.66-16.92; I2 = 0%).

CONCLUSIONS

Collectively, this systematic review demonstrated a 9% SFTP post-resection recurrence rate. Furthermore, the recurrence rates for benign and malignant SFTP were 3% and 22%, respectively. Histological malignancy and female sex were associated with higher risk.

Solitary fibrous tumor of the greater omentum: case report and review of literature

Background

Solitary fibrous tumor (SFT) is a rare neoplasm of mesenchymal origin occurring most often in the visceral pleura, however, it has been described in almost every anatomic location of the human body. While most SFTs have a benign behavior, they can potentially be locally aggressive and demonstrate a malignant behavior.

Case presentation

A 63 year-old male patient presented with lower abdominal pain and nausea and was noted on CT to have a large, heterogeneous lower abdominal mass with no evidence of metastatic disease. A surgical resection was performed and the mass appeared to be connected to the greater omentum with a vascular pedicle. It was not invading any intra-abdominal or pelvic organs. Pathology revealed an SFT of omental origin. The mitotic count was less than 4 per 10 high-power fields and all pathologic characteristics did not meet the criteria for a malignant SFT.

Conclusions

We report an extremely rare case of SFT originating from the greater omentum. A multidisciplinary team approach was followed to plan the patient’s management strategy.

Solitary Fibrous Tumor of the Pleura: A Simple Solution with a Simple Technique

Surgery has been the mainstay of treatment in managing patients with lung or pleural tumors. Surgery can be either a video-assisted or an open technique. Pre-operative investigation such as computed tomography (CT) scan of the thorax has been an important tool of assessment in deciding the approach of surgery. Traditionally, a tumor of more than 6 cm would necessitate an open approach. Herein, we would like to report a patient with a large solitary fibrous tumor of the pleura which was thoracoscopically excised and evacuated in an unconventional approach. Keywords: Solitary fibrous tumor, VATS, Pleura

Solitary fibrous tumor of the lesser omentum mimicking stomach gastrointestinal stromal tumor

Solitary fibrous tumor (SFT) is a mesenchymal tumor that rarely occurs in the abdomen. We report a very rare case of an abdominal SFT in the lesser omentum. A 39-year-old Korean man was referred to our center for management of a 9 cm incidental mass in the abdominal space found on a chest computed tomography (CT) during a routine medical examination. He had no symptoms, and there were no specific findings on physical examination. A contrast enhancement CT was performed, and an extraluminal gastrointestinal stromal tumor in the stomach or a pancreatic origin mass was suspected. Surgery was performed and an enclosed mass in the lesser omentum was observed, which was resected completely. The postoperative course was uneventful. Based on microscopy, the omental tumor was diagnosed as SFT.

Solitary fibrous tumor of the pleura with marked cystic degeneration: a case report

Background

Solitary fibrous tumor of the pleura (SFTP) is a mesenchymal tumor, and computed tomography typically shows SFTPs as well-defined lobulated masses. We herein report a case of SFTP with cystic degeneration of the entire tumor.

Case presentation

The patient was a 67-year-old Japanese man who was referred to our hospital for an abnormal shadow on a chest X-ray. Computed tomography showed a 9-cm cystic tumor in the lower left lobe, with small nodules aggregated in the cyst. Pulmonary aspergillosis was suspected, and left basal segmentectomy was performed. A pedunculated cystic tumor was connected to the pleura with a stalk, and white polypoidal masses were found within the cystic tumor. Microscopy revealed uniform fibroblastic spindle cell proliferation and marked cystic degeneration, the cyst walls were formed of the same tumor cells. Immunohistochemical staining revealed that the tumor cells were positive for CD34, CD99, and BCL2. Based on these findings, the tumor was diagnosed as SFTP with cystic degeneration.

Conclusion

We experienced an extremely rare case of atypical SFTP with cystic degeneration.

Solitary fibrous pleural tumor. A rare and challenging case

INTRODUCTION

Solitary fibrous tumor of the pleura (SFTP) is a rare tumor originating from mesenchymal tissue underlying the mesothelial pleural layer with only a limited number of reported cases. Benign and malignant SFTP usually appear as a well-defined, homogeneous, and rounded mass on imaging. Complete en bloc is usually the treatment of choice.

CASE PRESENTATION

44 years old gentleman presented with the unintentional weight loss and chest discomfort for 6 months. A CT scan of chest showed a 30 × 20 × 20 cm heterogeneously enhancing soft tissue mass involving the entire right hemithorax. PET scan showed a localized disease. Therefore, a complete right upper lobectomy and complete removal of mass was done, that resulted in complete expansion of the middle and lower lobe. The patient remains stable till date. Biopsy revealed a fibrous pleural tumor.

CONCLUSION

Complete surgical resection of the tumor is usually sufficient, but there are reported cases with recurrence. Wedge resection for complete excision can be carried out for tumors arising from visceral pleura. Extra pleural excision can be done without chest wall resection in tumors arising from the parietal pleura.

Predictors of behaviour in solitary fibrous tumours of the pleura surgically resected: Analysis of 107 patients

OBJECTIVES

Gold standard therapy for solitary fibrous tumour of the pleura is complete surgical resection. Aims of this retrospective study are to evaluate oncological and surgical outcomes and to verify the clinical reliability of prognostic scores presented in literature.

METHODS

Study population: 107 patients surgically treated between 1972 and 2018. Male/female ratio: 1/2.45; median age at surgery: 60 years (range, 19-80); peduncle lesions 69.8%; visceral pleura origin 72.9%; benign histology 73.8%; median diameter 8 cm (range 1 to 35, 27 cases giant [≥15 cm]).

RESULTS

After a median follow up of 7 years, 12 patients had recurrence. By multivariate analysis, malignant histology (P = .03; HR, 4.17; 95% CI, 1.15-15.06), origin from parietal pleura (P  = .03; HR, 3.90; 95% CI, 1.08-14.09), England (P = .002; HR, 1.98; 95% CI, 1.28-3.07), Diebold (P = .008; HR, 1.96; 95% CI, 1.20-3.22) and Tapias (P = .003; HR, 1.75; 95% CI, 1.20-2.53) scores were found independent significant predictors of relapse. Giant tumours were associated with open surgery (P = .003), origin from parietal pleura (P = .011) and intraoperative bleeding (P > .001). Overall 10-year disease-free survival (DFS) rate was 81%. Predictors of worst DFS were parietal pleura origin (P = .002), malignant histology (P = .006) and all the prognostic scores.

CONCLUSIONS

Malignant histology and origin from parietal pleura were significant predictors of tumour recurrence and worst DFS. The use of current scoring systems can help to predict clinical behaviour. Patients with higher risk of relapse can benefit from closer follow up, prolonged over 10 years.

Recurrence of multiple metastases after surgical removal of a primary malignant solitary fibrous tumor from the main bronchus: A case report

RATIONALE

Limited knowledge is available regarding solitary fibrous tumors (SFTs), about 15% of which are malignant. In particular, the long-term survival of patients with malignant SFTs (mSFTs), the disease course, and the potential for recurrence of second primary tumors or distant metastases are largely undetermined.

PATIENT CONCERNS

We report a rare case in which an mSFT was found at the main bronchus of the right lung of a 37-year-old man.

DIAGNOSIS

The tumor cells of mSFT were spindle-shaped and expressed antigen Ki-67, B-cell lymphoma 2, cluster of differentiation 31, and vimentin.

INTERVENTIONS

A total pneumonectomy was performed.

OUTCOMES

The patient developed fibrosarcoma of the small intestine at 6 months, as well as extensive pleural and peritoneal metastases at 1 year, after removal of the primary mSFT from the right main bronchus.

LESSONS

From these findings, we expect that patients with primary mSFT, especially of the lung, have a high potential to develop second tumors or distant metastases. Close monitoring after surgery is necessary to improve the outcomes of these patients.

Solitary fibrous tumor

Solitary fibrous tumor (SFT) is a rare tumor of mesenchymal origin that account for less than 2% of all soft tissue masses. Initially identified in the pleura, SFT has been identified in multiple anatomic locations and can arise anywhere in the body. The varying histologic features along with non-specific means of identification have led SFT to be associated with several different names. Over the last several decades, sustained advances through research and technology have led to more reliable methods for differentiating this distinct soft tissue tumor. Advances specifically in immunohistochemistry and molecular diagnostics have identified CD34 as the most consistent marker in SFT, however even this lacks specificity to conclusively narrow down the broad differential for exact identification. More recently the discovery of the NAB2-STAT6 fusion gene has led to more precise diagnosis of SFT. Like many other soft tissue tumors, surgical management is the mainstay of treatment for SFT with emphasis on obtaining tumor-negative margins. Radiation therapy and chemotherapy regimens have not demonstrated global effectiveness, and thus no standardized treatments have been identified. Given the rarity of SFT and current supportive evidence for therapies, management should be focused on tumor extirpation. Nonetheless, individualized therapy, determined within a multidisciplinary setting should be considered.

Solitary fibrous tumors of the pleura: A single center experience at National Cancer Center, China

BACKGROUND

This study explored the clinicopathological features, predictive factors of malignancy, effectiveness of video assisted thoracic surgery (VATS), and prognosis of solitary fibrous tumor of the pleura (SFTP).

METHODS

A single-center retrospective study of the data of 82 patients with SFTP who were surgically treated in our department between January 2003 and December 2015 was conducted.

RESULTS

A total of 82 SFTPs (70 benign, 12 malignant) were included and all patients underwent complete en bloc resection. SFTPs originated from the visceral pleura in 47 (57%) and the parietal pleura in 35 (43%) patients. In our cohort, malignant tumors were often symptomatically large, and the patients with malignant SFTPs (mSFTPs) often had a family history of neoplasms. Patients in the VATS group (n = 22) had tumors with significantly smaller diameters, required a shorter surgical duration and shorter hospital stay, and experienced less intraoperative blood loss and less postoperative chest tube drainage compared to the thoracotomy group (n = 60). No tumor recurrence was found in benign SFTP (bSFTP) patients. The long term survival and disease-free survival rates of mSFTP patients were 76% and 53%, respectively.

CONCLUSION

Larger tumor diameter and a family history of neoplasm may be predictive factors for mSFTP; however, this conclusion needs to be verified in large cohort. VATS is safe and reliable for treating selected SFTP patients. Local recurrence is associated with mSFTP patient death, thus close follow-up of such patients is crucial.

Giant solitary fibrous tumor of the pleura

Introduction: Solitary fibrous tumors of the pleura (SFTP) are rare mesenchymal tumors representing <5% of all tumors of the pleura. Literature reveals only two case series and a few solitary reports. Case report: A 68-year-old male presented to our hospital after experiencing exertional dyspnea. A chest CT revealed a giant heterogeneous mass. CT-guided transthoracic core needle biopsy demonstrated SFTP. The well-circumscribed, encapsulated resected mass was measured to be 30 cm × 21 cm × 15 cm and weighed 6900 g. Discussion: SFTP are a rare pathology of the pleural cavity, which most of the time develop from submesothelial fibroblasts of the visceral pleura. Due to their non-characteristic clinical picture, SFTP are usually diagnosed in the later stages of the development. A significant issue in the management of giant SFTP is radical resection of the tumor to relieve compression of the lung parenchyma and other mediastinal structures. Conclusion: SFTP are rare neoplasms that fortunately are benign 80% of the time. Only a few cases of giant SFTP that cover almost the entire pleural space are described in the literature. This report represents one of the largest resected SFTP reports in the literature.

Surgical therapy and next-generation sequencing-based genetic alteration analysis of malignant solitary fibrous tumor of the pleura

Background

Solitary fibrous tumor of the pleura (SFTP) is a rare pleural neoplasm arising from mesenchymal cells, accounting for <5% of pleural neoplasms. Approximately 10% of cases of SFTP demonstrate malignant potential, leading to local recurrence after radical surgery and subsequent metastasis.

Methods

A large malignant-like mass was found in the left thoracic cavity of a 61-year-old woman. Following radical resection of the mass, the patient was diagnosed with malignant SFTP by histologic and immunohistochemical analyses. In addition, a next-generation sequencing-based mutation test was used to reveal the mutational profile of the tumor. The genetic alteration panel was analyzed with reference to public data on the ClinVar and COSMIC databases, after which the public SFTP data were analyzed for frequency of altered genes. Finally, through overlay of the abovementioned two sets, the genetic alteration accounting for SFTP initiation was anticipated to be identified.

Results

In the mutation panel of our malignant SFTP group, kinase insert domain receptor (KDR) and fms-related tyrosine kinase 1 (FLT1) scored high in pathogenesis but had only a medium frequency; the NAB2–STAT6 fusion appeared to be the dominant genetic alteration in public SFTP samples.

Conclusion

The high frequency of NAB2–STAT6 fusion indicates its prominent role in SFTP, while somatic mutations such as FLT1-R593W and KDR-V297I may also contribute to the malignant angiogenic phenotype. The present study affirmed the heterogeneity of SFTP, and more sophisticated classification methods will be needed to explore its underlying mechanisms.

Summary

We believe that improvement in the prognosis of SFTP relies on early diagnosis, margin-free resection, and long-term follow-up. Through genetic analysis, it appears that both NAB2–STAT6 fusion and somatic mutations such as FLT1-R593W and KDR-V297I contribute to SFTP development.

A large solitary fibrous tumour of the pleura: a case report and review of the literature

We report a clinical case of a solitary fibrous tumour of the pleura (SFTP) in a 67-year-old female patient complaining of chest pain for 2 months. A localized large mass was found in the left inferior hemithorax by computed tomography scan. The patient underwent a thoracotomy at the left side with endotracheal anaesthesia. During surgical resection, the tumour was located in the left inferior hemithorax and was attached to the inferior lobe of the left lung and diaphragmatic pleura by a fibrous pedicle. A wedge resection of the left lower lobe was undertaken to completely remove the tumour. Diagnosis of the SFTP was confirmed by the surgical findings and subsequent histological and immunohistochemical examinations. At the 6-month follow-up, no signs of local tumour recurrence or metastasis were documented. After a 3-year follow-up, this patient remains in good health.

CT diagnosis and differentiation of benign and malignant varieties of solitary fibrous tumor of the pleura

To investigate computed tomography (CT) characteristics of benign and malignant solitary fibrous tumors of the pleura (SFTPs).Preoperative CTs for 60 SFTP cases (49 benign and 11 malignant) with subsequently confirmed diagnoses were retrospectively analyzed.Tumor morphologies included mounded or mushroom umbrella-shape (19 cases, 31.7%), quasi-circular or oval-shape (30 cases, 50%), and growth resembling a casting mould (12 cases, 20%). Maximum tumor diameters were 1.1 to 18.9 cm (average: 6.4 ± 4.8 cm). Fifty-seven cases had clear boundaries, and 3 had partially coarse boundaries. Twenty-seven cases showed homogeneous density; 33, "geographic"-patterned inhomogeneous density; 6, calcifications; 12, intratumor blood vessels; and 3, thick nourishing peritumoral blood vessels. Pleural thickening (regular and irregular) was found adjacent to tumors in 4, compression of adjacent ribs with absorption and cortical sclerosis in 2, and location adjacent to ribs with bony destruction in 1. Four cases had a small amount of lung tissue enfolded along the boundary, 2 had multiple peritumoral pulmonary bullae, and 9 had small ipsilateral pleural effusions. Compared with benign and malignant SFTPs were larger (P < .001), had inhomogeneous density, and were more commonly associated with intratumor blood vessels and pleural effusions (P < .01).CT revealed characteristic patterns in SFTPs, including casting mould-like growth, rich blood supply, and "geographic"-patterned enhancement. In addition, larger tumor size, inhomogeneous intensities, abundant intratumor blood vessels, and pleural effusions were more common with malignancy. Lastly, multislice CT angiography can reveal feeding arteries and help guide surgical management.

Giant solitary fibrous tumour of the pleura an unpredictable entity: case series and literature review

A small proportion of tumours can undergo malignant transformation. We report a case series of five patients diagnosed with giant solitary fibrous tumours of the pleura. These cases highlight the unpredictable nature of this disease process, with significant variability in clinical course observed, from indolence to aggressive progression. Three patients were found to have malignant disease on explant, with two of these having preoperative imaging and histology suggesting benign pathology. This finding emphasises that accurately differentiating between benign and malignant disease on imaging and/or biopsy has low specificity and sensitivity and cannot be relied upon in guiding the management of these tumours. Patients with solitary fibrous tumours of the pleura should be managed cautiously, owing to the unpredictable and potentially aggressive clinical course. We would advocate the position that all patients with solitary fibrous tumours of the pleura should be managed as if they have malignant disease. Prolonged follow-up is required due to the risk of disease recurrence, even in patients with benign disease.

Uncommon presentation of a rare tumour - incidental finding in an asymptomatic patient: case report and comprehensive review of the literature on intrapericardial solitary fibrous tumours

Background

A solitary fibrous tumour is a rare, mainly benign spindle cell mesenchymal tumour most commonly originating from the pleura. An intrapericardial location of a solitary fibrous tumour is extremely unusual. We present a case of an asymptomatic patient with a slow-growing massive benign cardiac solitary fibrous tumour.

Case presentation

A 37-year-old asymptomatic female patient was referred to our hospital with an enlarged cardiac silhouette found on her screening chest X-ray. The echocardiographic examination revealed pericardial effusion and an inhomogeneous mobile mass located in the pericardial sac around the left ventricle. Cardiac magnetic resonance (MRI) examination showed an intrapericardial, semilunar-shaped mass attached to the pulmonary trunk with an intermediate signal intensity on proton density-weighted images and high signal intensity on T2-weighted spectral fat saturation inversion recovery images. First-pass perfusion and early and late gadolinium-enhanced images showed a vascularized mass with septated, patchy, inhomogeneous late enhancement. Coronary computed tomography angiography revealed no invasion of the coronaries. Based on the retrospectively analysed screening chest X-rays, the mass had started to form at least 7 years earlier. Complete resection of the tumour with partial resection of the pulmonary trunk was performed. Histological evaluation of the septated, cystic mass revealed tumour cells forming an irregular patternless pattern; immunohistochemically, the cells tested positive for vimentin, CD34, CD99 and STAT6 but negative for keratin (AE1-AE3), CD31 and S100. Thus, the diagnosis of an intrapericardial solitary fibrous tumour was established. There has been no recurrence for 3 years based on the regular MRI follow-up.

Conclusion

Intrapericardial SFTs, showing slow growth dynamics, can present with massive extent even in completely asymptomatic patients. MRI is exceedingly useful for characterizing intrapericardial masses, allowing precise surgical planning, and is reliable for long-term follow up.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3574-0) contains supplementary material, which is available to authorized users.

Solitary Fibrous Tumor of the Pleura

BACKGROUND

The solitary fibrous tumor of the pleura (SFTP) is a rare primary tumor arising from mesenchymal cells in the areolar tissue subjacent to the mesothelial-lined pleura. Only about 800 cases have been reported in the medical literature. The tumor appears to be unrelated to malignant pleural mesothelioma, the most common primary tumor of the pleura.

METHODS

In just over half of these cases, the neoplasm presents as an asymptomatic mass, is often quite large, and is benign in 78% to 88% of patients. The initial evaluation and diagnosis, tumor classification, surgical treatment, results of therapy, and long-term prognosis are reviewed, based on a selective review of the literature from MEDLINE beginning 1980.

RESULTS

Complete en bloc surgical resection is the preferred treatment of benign and malignant varieties of the tumor. The pedunculated tumors attached to the visceral pleura can be effectively treated with a wedge resection of lung. Sessile tumors arising on the lung require a larger lung resection. Sessile tumors on the chest wall require wide local excision, often with chest wall resection because of their propensity for local recurrence. Adjuvant therapy remains controversial in SFTP.

CONCLUSIONS

Benign SFTP has a high cure rate and an 8% local recurrence rate that is usually amenable to curative re-excision. Malignant SFTP, especially the more common sessile type, has a 63% recurrence rate even with complete resection. The majority of patients with recurrent disease die of the tumor within 2 years. Nevertheless, the overall long-term cure rate for all patients is 88% to 92%.

Doege-potter syndrome: a report of a histologically benign but clinically malignant case

Background

Solitary fibrous tumors of the pleura (SFTPs) are relatively rare tumors that originate from mesenchymal cells of submesothelial tissue of the pleura. Most patients with SFTPs are asymptomatic; however, pleuritic chest pain, cough, and dyspnea can develop. If hypoglycemia is associated with a solitary fibrous tumor, it is referred to as the Doege-Potter syndrome.

Case presentation

A 70-year-old man had visited our hospital with a chief complaint of dyspnea, and he was diagnosed as having a solitary fibrous tumor. A few years later, he developed hypoglycemia, and he underwent excision of the mass.

Conclusion

Occasionally, SFTPs induce several paraneoplastic events, such as hypertrophic osteoarthropathy. We described here a patient with an SFTP with Doege-Potter syndrome who was successfully treated with complete resection. Although lesions can be histologically benign, they can clinically present with malignant features.

Solitary fibrous tumour: a rare tumour of the pleural cavity

Solitary fibrous tumours are a rare group of tumours that originate from connective tissues such as the pleura and mediastinum. When growing within the thoracic cavity these tumours exert pressure on vital organs and large vessels. We have successfully operated on two patients with large solitary fibrous tumours and managed the pathophysiological changes manifested as superior vena cava syndrome resulting from these tumours.

Mediastinal Solitary Fibrous Tumor Diagnosed by Endobronchial Ultrasound-Directed Biopsy

BACKGROUND Solitary fibrous tumors of the middle mediastinal space are uncommon and often not discovered until symptoms secondary to compression of adjacent structures occur. Diagnosis requires surgical biopsy and histological tissue analysis. We describe the ECHO appearance of the solitary fibrous tumor and successful non-invasive EBUS diagnosis. This method of diagnosis allowed for surgical planning for resection and allowed us to exclude non-surgical diseases, such as small cell carcinoma. CASE REPORT A 32-year-old man presented to his primary care physician with worsening intermittent chronic chest pain with recent progressive dysphagia, cough, and dyspnea. Physical examination and routine laboratory work-up were unrevealing. Chest radiograph and computed tomography (CT) of the chest revealed a middle mediastinal mass. Flexible bronchoscopy confirmed extrinsic compression of right and left bronchial trees. Endobronchial ultrasound (EBUS) was used to biopsy the mass and the diagnosis of solitary fibrous tumor was confirmed. The patient underwent successful tumor resection and was discharged home after an uneventful postoperative period. CONCLUSIONS Endobronchial ultrasound-directed tissue biopsy is an appropriate modality for suspected solitary fibrous tumors of the mediastinum. To our knowledge, this is only the second reported case of SFT diagnosed by EBUS-TBNA. Our case uniquely demonstrates the advantages of pre-surgical diagnosis of mediastinal masses with EBUS-TBNA when the diagnosis SFT is suggested on CT and US imaging.

Solitary Fibrous Tumor of the Pleura With Abdominal Aortic Blood Supply

A solitary fibrous tumor of the pleura (SFTP) presenting with an aberrant arterial supply from the abdominal aorta is extremely rare, and it may be difficult to distinguish from intralobar sequestration (ILS). We report the case of a 38-year-old woman who presented with acute chest pain and was subsequently found to have a 17.5-cm intrathoracic mass. After preoperative arterial embolization of its feeding vessel, this presumed ILS was resected. However, the intraoperative findings revealed a benign SFTP. Here we discuss a unique presentation of a large SFTP radiographically mimicking an ILS, and we propose a safe management strategy for this entity.

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.

Solitary Fibrous Tumors of Chest: Another Look with the Oncologic Perspective

Solitary fibrous tumors are mesenchymal lesions that arise at a variety of sites, most commonly the pleura. Most patients are asymptomatic at diagnosis, with lesions being detected incidentally. Nevertheless, some patients present due to symptoms from local tumor compression (eg. of the airways and pulmonary parenchyma). Furthermore, radiological methods are not always conclusive in making a diagnosis, and thus, pathological analysis is often required. In the past three decades, immunohistochemical techniques have provided a gold standard in solitary fibrous tumor diagnosis. The signature marker of solitary fibrous tumor is the presence of the NAB2-STAT6 fusion that can be reliably detected with a STAT6 antibody. While solitary fibrous tumors are most often benign, they can be malignant in 10-20% of the cases. Unfortunately, histological parameters are not always predictive of benign vs malignant solitary fibrous tumors. As solitary fibrous tumors are generally regarded as relatively chemoresistant tumors; treatment is often limited to localized treatment modalities. The optimal treatment of solitary fibrous tumors appears to be complete surgical resection for both primary and local recurrent disease. However, in cases of suboptimal resection, large disease burden, or advanced recurrence, a multidisciplinary approach may be preferable. Specifically, radiotherapy for inoperable local disease can provide palliation/shrinkage. Given their sometimes -unpredictable and often- protracted clinical course, long-term follow-up post-resection is recommended.

Challenges in diagnosis and management of giant solitary fibrous tumour of pleura: a case report

Background

Majority of patients with solitary fibrous tumours of the pleura (SFTP) are asymptomatic. Acute presentation with symptoms resulting from mass effect due to rapid expansion of tumour size has not been reported before.

Case presentation

This report chronicles the case of a giant SFTP in a 76-year-old lady who presented with acute onset of haemoptysis, left-sided pleuritic chest pain and hoarseness of voice. Her chest radiograph showed a large left upper hemithorax mass with an ipsilateral effusion. Computed tomography (CT) scan of the thorax confirmed the presence of a pleural-based mass lesion in the left apex measuring 9.7 cm with close apposition to the aortic arch. The mass demonstrated neovascularization and there was also presence of a moderate-sized heterogeneous-appearing left pleural effusion. Thoracocentesis yielded deeply haemoserous pleural fluid with a pleural aspirate hematocrit closely approaching that of peripheral blood hematocrit and alongside a 2 unit decrease in haemoglobin, was indicative of a haemothorax. Repeat CT 10 days from initial presentation showed reduction in size of the left apical mass as well as resolution of the left effusion. This was consistent with the occurrence of an intra-tumoural bleed resulting in rapid increase in the size of the SFTP, causing rupture of superficial blood vessels on the tumour surface (haemothorax) and consequential compression of the lung parenchyma (haemoptysis) and left recurrent laryngeal nerve (hoarseness of voice). The patient eventually underwent an uneventful surgical resection.

Conclusion

A benign SFTP can present acutely with compressive symptoms as a result of spontaneous intra-tumoural bleed causing sudden increase in its size. It is important to allow temporal regression of these acute changes before deciding on surgical resectability.

Solitary Fibrous Tumor of the Pleura: A Rare Cause of Pleural Mass

BACKGROUND

A solitary fibrous tumor of the pleura is a rare but usually benign mesenchymal tumor arising from the pleura. Patients are often asymptomatic, resulting in the majority of tumors being detected incidentally on chest imaging. We present a case of a large solitary pleural tumor and review the typical radiographic and pathologic findings associated with this finding.

CASE REPORT

A 63-year-old white man with chronic obstructive pulmonary disease (COPD) was found to have a large pleural mass on chest radiography during a pre-operative assessment. The tumor was biopsied and findings were consistent with solitary fibrous tumor of the pleura.

CONCLUSIONS

SFTPs are generally considered benign tumors although there is a risk of malignant transformation and recurrence. Imaging studies play an important role in identifying the tumor and planes of resection, and histologic diagnosis is critical in differentiating SFTP from other type of pleural masses. Surgical resection is main therapy of choice.

Giant solitary fibrous tumour of the pleura. Case report and review of the literature

Background

Solitary fibrous tumours of the pleura (SFTP) are rare tumours. They are mostly benign. Only around 12% of them are malign ant. In the initial stage they are mostly asymptomatic and by growing they cause chest pain, irritating cough and dyspnoea on account of the pressure created on the surrounding structures. Rare giant tumours have compression symptoms on the mediastinal structures. The condition requires tiered diagnostic radiology. Preoperative biopsy is not successful in most cases. The therapy of choice is radical surgical tumour removal. Malignant or non-radically removed benign solitary fibrous tumours of the pleura additionally require neoadjuvant therapy.

Case report

A 68-year old patient was hospitalized for giant solitary fibrous tumour of the pleura in the right pleural cavity. With its expansive growth the tumour caused the shift of the mediastinum by compressing the lower vena cava, right cardiac auricle as well as the intermediate and lower lobe bronchus. Due to cardiac inflow obstruction and right lung collapse, the patient’s life was endangered with signs of cardio-respiratory failure. After preoperative diagnostic radiology, the tumour was surgically removed. Postoperatively, the patient’s condition improved. No disease recurrence was diagnosed after a year.

Conclusions

Giant solitary fibrous tumour of the pleura may cause serious and life-threatening conditions by causing compression of the pleural cavity with its expansive growth. Early diagnosis of the condition enables less aggressive as well as video-assisted thoracic surgery in patients with significantly better state of health. Large tumour surgeries in cardio-respiratory affected patients are highly risk-associated procedures.

Solitary fibrous tumor of the pleura - analysis of 18 cases

Introduction

Solitary fibrous tumors of the pleura (SFTP) are primary tumors arising from mesenchymal cells. Immunohistochemical studies have demonstrated that the origin of these tumors is mesenchymal rather than mesothelial. The aim of this study is to present our experience with diagnosing and treating patients with SFTP.

Material and methods

We analyzed 18 patients treated at the Department of Thoracic Surgery of the Medical University of Lodz. The patients’ medical histories and the results of postoperative histopathological investigation of the tumors were analyzed. Postoperative histopathological samples were evaluated with regard to the current criteria of malignancy.

Results

In 17 patients, the tumors were surgically removed. Benign and small lesions (less than 3 cm in size) were removed by video-assisted thoracoscopic surgery (VATS). In 5 cases, malignant tumors were found in the postoperative material.

Conclusions

Solitary fibrous tumors of the pleura is a tumor with frequently asymptomatic clinical course. Treatment consists in resection which includes the adjacent structures, especially if the tumor is malignant.

Importance of NAB2-STAT6 Fusion in the Diagnosis of Pancreatic Solitary Fibrous Tumor with Hamartoma-Like Features: A Case Report and Review of the Literature

We report a case of pancreatic hamartoma-like solitary fibrous tumor which was differentiated from pancreatic hamartoma with the detection of NAB2-STAT6 fusion, a specific mutation for solitary fibrous tumors. A pancreatic well-demarcated solid nodule, 21 × 17 mm, of 82-year-old man was surgically enucleated. Microscopic findings were close to a pancreatic hamartoma that consisted of sparsely distributed pancreatic ducts and acini in heavily collagenized fibrous stroma. Neither islet nor peripheral nerve existed in the tumor. The fibroblastic cells in the stroma were immune-positive for CD34, CD99, and bcl-2. But these expressions were not decisive in the differentiation between solitary fibrous tumor and pancreatic hamartoma, because CD34 was positive for both tumors, and CD99 and bcl-2 expressions were not elucidated in the previous cases of pancreatic hamartomas. Thus, we evaluated NAB2-STAT6 fusion. The fibroblastic cells were positive for STAT6 and sequencing analysis revealed the gene fusion between NAB2 exon 4 and STAT6 exon 2, with which the final diagnos is of solitary fibrous tumor was achieved. In conclusion, detection of NAB2-STAT6 fusion has a great diagnostic value for pancreatic solitary fibrous tumors with hamartoma-like features.

Solitary fibrous tumors of the pleura: review of literature with up-to-date observations

Solitary fibrous tumors of the pleura (SFTP) are rare mesenchymal tumors with unpredictable biologic characteristics. Attempts have been made to standardize prognostic criteria without improvement in predicting prognosis or recurrence. The infrequent nature of this tumor contributes to the paucity of data that are used to make useful observations. Here, we present a comprehensive review of contemporary literature to summarize important clinical management aspects of patients with SFTP, focusing on surgical treatment, the role for adjuvant therapies, the potential impact of new prognostic models and the management of recurrences. SFTP remains poorly understood; therefore, new information such as a detailed molecular characterization may improve current prognostic models and lead to new treatment strategies.

Solitary fibrous tumor of the pleura: morphogenesis and progression. A report of 36 cases

PURPOSE

We attempted to identify the exact point of tumor eruption of a solitary fibrous tumor of the pleura (SFTP).

METHODS

We morphologically classified 36 SFTPs into 5 categories. Type A showed a connection that included a bloodstream with the pleura on both sides. Type B only showed a connection that included a bloodstream with the visceral pleura, and had a non-bloodstream connection with the parietal pleura. Type C only showed a connection that included a bloodstream with the visceral pleura, and had no connection with the parietal pleura. Type D showed a non-bloodstream connection with the visceral pleura, and only showed a connection that included a bloodstream with the parietal pleura. Finally, type E had no connection with the visceral pleura, and only showed a connection that included a bloodstream with the parietal pleura. The clinicopathological profiles of the tumors were investigated according to their type.

RESULTS

The distribution of the 36 SFTPs was as follows: A (19 %), B (6 %), C (67 %), D (0 %) and E (8 %). The tumors categorized as type A tended to be large in size.

CONCLUSIONS

SFTPs commonly arise from the visceral pleura and in accordance with tumor progression they will form a non-bloodstream connection with the parietal pleura. Finally, a vascular pedicle will arise with the parietal pleura.

Validation of a scoring system to predict recurrence of resected solitary fibrous tumors of the pleura

BACKGROUND

Solitary fibrous tumors of the pleura (SFTPs) are infrequent neoplasms with no standardized criteria to predict risk of recurrence after curative surgery. The aim of the present study is to validate a recently proposed recurrence score in a large European cohort of patients with SFTP.

METHODS

Validation of a previously published scoring system was assessed in a population of 113 patients who underwent complete resection of SFTPs. Patients were scored according to the pleural origin, morphology, size, hypercellularity, presence of necrosis or hemorrhage, and number of mitoses in their SFTPs. Receiver operating characteristic curves were plotted for the score. Time to recurrence analysis was performed using the Kaplan-Meier and Cox proportional hazards methods.

RESULTS

After a mean follow-up of 13.2 ± 7.3 years, there were nine recurrences (8.0%). Score performance to predict recurrence was as follows: sensitivity = 78%, specificity = 74%, positive likelihood ratio = 3.0, and negative likelihood ratio = 0.3. A cutoff of 3 points was used to classify 79 patients (69.9%) at low risk and 34 patients (30.1%) at high risk for recurrence. A high-risk classification was significantly associated with more recurrences during follow-up (P = .004), worse overall survival (P = .0008), more extensive lung resections (P = .001), and the use of adjuvant therapies (P = .009). The present score outperformed England's criteria (P = .049) and de Perrot classification (P < .001) when predicting SFTP recurrence.

CONCLUSIONS

The proposed scoring system, which combines common clinical and histologic features of resected SFTPs, remains predictive of recurrence in a separate patient population. The simple score may guide the postoperative surveillance of this uncommon tumor.