Management of solitary fibrous tumours of the pleura: a systematic review and meta-analysis

Nonmesothelial Spindle Cell Tumors of Pleura and Pericardium

Spindle cell lesions of the pleura and pericardium are rare. Distinction from sarcomatoid mesothelioma, which has a range of morphologic patterns, can be difficult, but accurate diagnosis matters. This article provides practical guidance for the diagnosis of pleural spindle cell neoplasms, focusing on primary lesions.

Solitary pleural fibroma causing IGF-2-mediated hypoglycaemia in a non-diabetic patient

A patient without a diagnosis of diabetes mellitus presented to the hospital due to a fall and hypoglycaemia on admission. The patient was found to have recurrent nocturnal fasting hypoglycaemia. CT revealed a large lung mass consistent with a solitary pleural fibroma, a rare tumour associated with insulin-like growth factor 2 (IGF-2) production. This case is an important reminder that potential causes of hypoglycaemia should be considered in non-diabetic patients.

Risk factors for recurrent disease after resection of solitary fibrous tumor: a systematic review

Introduction

Solitary fibrous tumor (SFT) is a rare soft tissue tumor found at any site of the body. The treatment of choice is surgical resection, though 10%-30% of patients experience recurrent disease. Multiple risk factors and risk stratification systems have been investigated to predict which patients are at risk of recurrence. The main goal of this systematic review is to create an up-to-date systematic overview of risk factors and risk stratification systems predicting recurrence for patients with surgically resected SFT within torso and extremities.

Method

We prepared the review following the updated Prisma guidelines for systematic reviews (PRISMA-P). Pubmed, Embase, Cochrane Library, WHO international trial registry platform and ClinicalTrials.gov were systematically searched up to December 2022. All English studies describing risk factors for recurrence after resected SFT were included. We excluded SFT in the central nervous system and the oto-rhino-laryngology region.

Results

Eighty-one retrospective studies were identified. Different risk factors including age, symptoms, sex, resection margins, anatomic location, mitotic index, pleomorphism, hypercellularity, necrosis, size, dedifferentiation, CD-34 expression, Ki67 index and TP53-expression, APAF1-inactivation, TERT promoter mutation and NAB2::STAT6 fusion variants were investigated in a narrative manner. We found that high mitotic index, Ki67 index and presence of necrosis increased the risk of recurrence after surgically resected SFT, whereas other factors had more varying prognostic value. We also summarized the currently available different risk stratification systems, and found eight different systems with a varying degree of ability to stratify patients into low, intermediate or high recurrence risk.

Conclusion

Mitotic index, necrosis and Ki67 index are the most solid risk factors for recurrence. TERT promoter mutation seems a promising component in future risk stratification models. The Demicco risk stratification system is the most validated and widely used, however the G-score model may appear to be superior due to longer follow-up time.

Systematic Review Registration

CRD42023421358.

Intrapulmonary solitary fibrous tumor with malignant potential: A case report

Intrapulmonary solitary fibrous tumor is rare, and its clinical course has not been sufficiently reported. We presented a case of an 80-year-old male non-smoker and discussed the surgical procedure selection and the recurrence risk assessment. A solid nodule, 1.1 cm in diameter, was identified in the left lower lobe on chest computed tomography and showed no accumulation on positron emission tomography. A wedge resection with a sufficient surgical margin under video-assisted thoracoscopic surgery was performed. Based on histological morphology and immunohistochemical examination, this case was considered an intrapulmonary solitary fibrous tumor with malignancy potential, requiring cautious follow-up observation.

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.

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.

Solitary fibrous tumour of the pleura: a rare cause of digital clubbing

A woman in her early 70s was found to have incidental finger clubbing at a fracture clinic consultation for an unrelated problem. She reported no associated respiratory symptoms and was referred back to her General Practitioner for further investigation. A chest radiograph revealed a large left-sided mass. This was characterised as a pleural-based mass on CT, resulting in localised atelectasis and mediastinal shift. A CT guided biopsy revealed histology consistent with a solitary fibrous tumour of the pleura and the patient was referred for thoracotomy and resection.

A female with solitary fibrous tumor pleura mimicking pulmonary sclerosing pneumocytoma in low resource setting: A case report

Background

Solitary fibrous tumor of pleura (SFTP) is a rare condition. Clinical symptoms and non-specific radiological features in both tumors make preoperative diagnosis difficult to establish.

Case presentation

A Javanese 47-year-old female complained of chest pain and shortness of breath which an X-ray and CT-Scan of the thorax showed giant cell metastases in the lung. Signs and symptoms indicate pulmonary sclerosing pneumocytoma (PSP) and the patient underwent thoracic surgery which was first performed with angiographic embolization. Furthermore, an anatomical pathology analysis was performed with suspected SFTP, supported by the IHC test, which found CD34 (+), EMA (−), and S100 (−). Thoracic surgery followed by radiotherapy and chemotherapy is recommended in SFTP patients.

Discussion

The SFTP and PSP have non-specific clinical symptoms and radiological features. Anatomic pathology and IHC test are definitive diagnostic tools from SFTP and PSP. Establishing a preoperative diagnosis of SFTP and PSP is quite difficult. Surgical resection is the treatment of choice for both.

Conclusion

The comparison of SFTP and PSP can be seen results of the anatomical pathology analysis and IHC test.

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Solitary fibrous tumor of pleura (SFTP) and pulmonary sclerosing pneumocytoma (PSP) are difficult to distinguish in a low-resource setting.

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SFTP and PSP can be differentiated using an immunohistopathology test (cluster of differentiation 34/CD54 was positive).

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Management of SFTP and PSP are both similar to surgery (thoracotomy with a subcostal incision).

18F-FDG PET/CT characteristics of solitary fibrous tumour of the pleura: single institution experience

BACKGROUND

To date, published studies have shown that ¹⁸F-FDG PET/CT and CT have limited value in differentiating benign and malignant solitary fibrous tumours of the pleura (SFTP). This study aimed to determine whether the metabolic and morphological characteristics of ¹⁸F-FDG PET/CT can be a valuable addition to diagnostic tools for SFTPs.

METHODS

From January 2016 to November 2021, we performed a retrospective review in 32 SFTPs patients who underwent ¹⁸F-FDG PET/CT scan. All the SFTP diagnoses were confirmed by surgical resection or biopsy samples. The metabolic parameters (including SUVmax, SUVmean, MTV, TLG, and SULmax) were obtained from ¹⁸F-FDG PET/CT images.

RESULTS

Thirty-two patients with SFTP were consecutively identified. The malignant SFTPs have higher Ki-67 expression (P = 0.005). The study observed that tumour heterogeneity without contrast injection (P = 0.001) and intratumor blood vessels (P = 0.047) were morphological features associated with malignant SFTP. Malignant SFTP was more frequently observed with higher SUVmax values (P = 0.001), higher SUVmean values (P = 0.001), higher TLG values (P = 0.006), and higher SULmax values (P < 0.001). For predicting malignant SFTP, the AUC values of SUVmax, SUVmean, TLG, and SULmax obtained by the area under curve analysis were 0.970 (95% CI 0.907-1.000; P = 0.001), 0.874 (95% CI 0.675-1.000; P = 0.009), 0.807 (95% CI 0.654-0.961; P = 0.031), and 0.911 (95% CI 0.747-1.000; P = 0.004), respectively.

CONCLUSION

The study showed that metabolic and morphological features were useful for distinguishing malignant from benign SFTPs.

Pleural nodule with osteal protrusion anterior to the rib tubercle: a case report

Pleural soft tissue density nodules with osteal protrusions are often detected at their characteristic site, the anterior portion of the rib tubercle. Herein, we report a pathologically proven case of this lesion. A 65-year-old man underwent surgery for primary lung cancer in the right middle lobe. Preoperative computed tomography showed a 10-mm pleural soft tissue density nodule with osteal protrusion anterior to the tubercle of the right sixth rib, and this lesion was concomitantly resected. Intraoperative findings showed that this pleural lesion originated from the parietal pleura and was pathologically diagnosed as a benign fibrous tissue. We can avoid unnecessary invasive examinations such as biopsies by recognizing these benign fibrous lesions.