[(18)F]-FDG PET and localized fibrous mesothelioma

[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.

Solitary fibrous tumor arising from pelvic retroperitoneum: A report of two cases and a review of the literature

Solitary fibrous tumors (SFT) rarely arise in the pelvis. Here, we report two cases of SFT arising from the pelvic retroperitoneum. The first case involves a 64-year-old woman diagnosed with a 5-cm pelvic mass. Magnetic resonance imaging revealed a solid and cystic mass with marked enhancement, but limited water restriction. During surgery, intraligamental tumor arising near the round ligament was resected. Pathologically, the tumor comprised dilated vessels and spindle-shaped cells positive for STAT6 and CD34. The second case involves a 53-year-old woman diagnosed with a 4.5-cm pelvic mass through computed tomography. Magnetic resonance imaging demonstrated a solid mass with multiple cysts with strong enhancement and slight water restriction. During surgery, the tumor was found in the retroperitoneum. Pathologically, spindle-shaped tumor cells positive for STAT6 and CD34 had proliferated around the prominent hyalinized vessels. Although rare in the pelvis, SFT should be suspected when a mass with strong enhancement is found.

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.

Solitary fibrous tumour of the mesentery: a case report

We present the case of a male with an asymptomatic abdominal mass, where imaging-guided biopsy confirmed the lesion as a solitary fibrous tumour arising from the mesentery. This is a notably rare location for solitary fibrous tumours with only a few reported cases in the literature.

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%.

Solitary Fibrous Tumors: 2016 Imaging Update

Optimal management of solitary fibrous tumor requires a multidisciplinary approach with proper histopathological mapping and use of various imaging modalities for exact delineation of primary tumor and metastatic disease if present. In this article, the authors present a comprehensive review of the spectrum of imaging findings of solitary fibrous tumors involving various organ systems and discuss the role of molecular targeted therapies in the management of metastatic disease.

Solitary fibrous tumors of the pleura

PURPOSE OF REVIEW

Solitary fibrous tumor of the pleura (SFTP) is a rare neoplasm of the pleura. Although an increasing number of case series have been reported in recent years, so far clinical behavior is still unpredictable. The following article presents a detailed review of the recent larger series of SFTP with particular attention to the clinical presentation, pathologic characteristics and surgical features in order to define more precisely the long-term outcome after treatment of this rare entity.

RECENT FINDINGS

Usually, after a complete surgical resection a very long survival could be expected in almost all cases. However, the preoperative detection and management of malignant SFTPs are still challenging issues.

SUMMARY

SFTP remains an enigmatic tumor. Clinical and radiological assessment is often unsatisfactory to obtain a definitive diagnosis. Benign SFTPs are almost always cured with complete surgical resection, and in cases of recurrence the re-do resection of benign recurrences is usually curative. Long-term survivals are also possible for malignant SFTPs, although a higher recurrence rate and higher tumor-related mortality can be expected in these cases. Histologic characteristics distinguishing benign from malignant variants are crucial in estimating the risk of recurrence and planning adjuvant therapies.

Imaging of benign solitary fibrous tumor of the pleura: a pictorial essay

Solitary fibrous tumor of the pleura (SFTP) is a mesenchymal tumor that tends to involve the pleura, and is also described in other thoracic and extrathoracic sites. SFTP usually presents as a peripheral mass abutting the pleural surface, to which it is attached by a broad base or by a pedicle that allows it to be mobile. SFTPs exist in benign and malignant forms. A precise pre-operative diagnosis can be arrived at with a cutting-needle biopsy, although most cases are diagnosed with postoperative histology and immunohistochemical analysis. In this pictorial essay, we review a large series of cases, with emphasis on the radiographic appearance of these lesions and their findings from computed tomography, magnetic resonance imaging, ultrasonography and positron emission tomography.

Diagnosis, treatment and long-term outcome of solitary fibrous tumours of the pleura

OBJECTIVE

Solitary fibrous tumours of the pleura (SFTP) are rare and can histologically be differentiated into benign and malignant forms. The aim of this study is to present new cases, and discuss up-to-date preoperative examinations, the role of video-assisted thoracic surgery and long-term outcome.

METHODS

Between 1993 and 2006, 27 SFTPs were diagnosed (14 females, mean age+/-SD, 62.3+/-9.6 years) at our institution. Medical records were reviewed, and follow-up was obtained by repeated examinations or contact with general practitioners.

RESULTS

SFTPs were associated with symptoms in 63% of all cases. In the six patients in which positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) was performed preoperatively, malignant lesions were all found to be positive. Complete resection was achieved by video-assisted thoracic surgery in 15 and anterolateral thoracotomy in 12 patients. Mean hospital stay was shorter for patients operated by video-assisted thoracic surgery compared to thoracotomy, 4.5 (range 3-6) versus 7.5 (range 4-25) days, respectively (p<0.01). Histology revealed 17 benign and 10 malignant SFTP. Mean+/-SD tumour diameter of malignant SFTPs was larger than in benign forms, 11.9+/-7.1 versus 6.1+/-3.5 cm, respectively (p<0.01). Tumour recurrence was recognised in four patients with malignant SFTPs at a median time interval after surgery of 38 (range 6-122) months, two late deaths occurred resulting from tumour recurrences.

CONCLUSIONS

SFTPs can be treated minimally invasively by video-assisted thoracic surgery with short hospital stay. Large SFTPs with increased FDG-uptake have a high likelihood for malignancy. Long-term follow-up is mandatory in malignant SFTPs because of late recurrences associated with death.

[18-Fluoro-deoxy-glucose (15FDG) positon emission tomography (PET) for the evaluation of malignant pleural disease]

Use of 18FDG-PET for malignant tumors of the pleura raises certain technical difficulties because of the small size of the tumors and their diffuse distribution, but hybrid PET/CT machines offer a better localization of FDG uptake. FDG-PET can discriminate between malignant and benign pleural tumors FDG uptake in the pleura is the best diagnostic criteria of malignancy. The presence of FDG uptake in pleural effusion is less discriminate between benign and malignant disease. For mesotheliomas, FDG-PET can difference malignant tumors from benign tumors of the pleura on the basis of the SUV value (<or > 2). It does not enable detection of mediastinal node involvement and regional extension but is effective in detecting extra-thoracic regional spread not identified with other imaging methods. FDG-PET can thus affect the therapeutic strategy. The intensity of uptake has prognostic value. SUV<4 associated with an epithelial tumor is a sign of good prognosis at three years. SUV > 4 associated with a non-epithelial tumor is a sign of poor prognosis. For mesotheliomas, FDG uptake can be used to assess the effect of chemotherapy and determine whether patients are good responders or not.

Localized Fibrous Tumors of the Pleura: Experience With 7 Recent Cases

OBJECTIVE

Localized fibrous tumors of the pleura are rare. We report 7 cases and review the literature in order to define the range of clinical characteristics of these tumors, treatment options, and prognosis.

METHODS

A retrospective review of 7 cases treated between 1997 and 2003, focusing on clinical presentation, diagnostic tests, and treatment. The tumor was removed surgically in all cases, by thoracotomy in 6 cases and by video-assisted thoracoscopic surgery in 1 patient.

RESULTS

All patients recovered fully after surgery, with no postoperative complications. One patient experienced recurrence twice, 33 and 67 months after the initial resection. All are alive at the time of writing, after a mean follow up period of 19 months (range 1 month to 5 years and 10 months).

CONCLUSIONS

The treatment of choice for a fibrous tumor of the pleura is full resection and follow-up to detect possible late recurrence.