Solitary fibrous tumor of the pleura

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.

MR Imaging of Pleural Neoplasms

The pleura may be affected by primary tumors or metastatic spread of intrathoracic or extrathoracic neoplasms. Primary pleural neoplasms represent ∼10% of all pleural tumors, and malignant lesions are more common than benign lesions. The most common primary tumors include malignant pleural mesothelioma and solitary fibrous tumor. Although pleural neoplasms may initially be evaluated with computed tomography (CT) and/or fluorodeoxyglucose positron emission tomography (PET)/CT, magnetic resonance (MR) imaging is complementary to these other imaging modalities for disease staging and evaluation of patients. In this article, we discuss the etiology, clinical presentation, and imaging of pleural neoplasms, with specific attention given to the role of MR imaging.

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 of the Pleura: A Case Report and Review of the Literature

Background

Solitary fibrous tumors of the pleura are rare and slow-growing neoplasms originating from the mesenchymal tissue underlying the mesothelial layer of the pleura. These tumors may have an unpredictable clinical course. Most cases occur in the sixth or seventh decades of life with no gender predilection, and more than 80% of cases are benign. The predominant clinical symptoms and signs are dyspnea, cough, chest pain, finger clubbing and hypoglycemia. However, because many patients are asymptomatic, the incidence rates are affected by the likelihood of its incidental detection, often through medical imaging of the chest. Surgical resection is the treatment of choice and is usually curative, even though local recurrence can occur many years after an adequate resection.

Methods

We reviewed the literature by performing a computerized search of MEDLINE, CANCERLIT and Embase with the terms fibrous tumor, pleura, surgery, immunohistochemical analysis. Articles and abstracts were also identified by back-referencing from other relevant papers.

Results

The clinical, radiological and pathological features of a 48-year-old woman with a primary solitary fibrous tumor of the pleura are reviewed and a literature search for other reported cases has been performed.

Conclusions

Although localized fibrous tumors of the pleura are considered histologically benign, there is a risk of recurrence and malignant transformation. Complete surgical resection is mandatory and long-term clinical and radiological follow-up is indicated in all patients. For malignant cases complete surgical resection may not be adequate and studies are needed to define the role of preoperative and postoperative systemic treatment. Diagnosis is very difficult in limited samples such as fine-needle aspiration or needle-core tissue biopsy, and immunohistochemical analysis may be useful to differentiate solitary fibrous tumor of the pleura from mesothelioma and other similar tumors.

A 39-year-old man with dyspnoea, low forced expiratory volume and a large mass of the left hemithorax

In patients with intrathoracic neoplasms, low forced expiratory volume (FEV₁) can preclude surgical treatment. Here, we present a case of a giant solitary fibroma of the pleura (SFTP) successfully treated by surgical removal in spite of low FEV₁. A 39-year-old male patient was referred to our hospital with dyspnoea and chest distress. Computed tomography (CT) showed a large mass in the left chest. Spirometry showed FEV₁ 1.4 L (39% of the expected value). Computed tomography scan-guided transcutaneous aspiration biopsy was performed on the patient, and microscopic examination of the specimen revealed spindle tumor cells with a background of abundant collagen. Complete surgical resection was accomplished. The tumor was large and encapsulated. It measured 28 cm × 20 cm × 18 cm. The definitive diagnosis obtained by histopathology after resection was benign SFTP. The patient felt no dyspnoea at discharge. Surgical treatment of SFTP should be considered even in patients with a huge tumor and with increased post-operative risk.

Giant solitary fibrous tumor arising from greater omentum

Extrathoracic solitary fibrous tumors (SFTs) have been described at almost every anatomic location of human body, but reports of SFT in the abdominal cavity are rare. We herein present a rare case of SFT originating from greater omentum. Computed tomography revealed a 15.8 cm × 21.0 cm solid mass located at superior aspect of stomach. Open laparotomy confirmed its mesenchymal origin. Microscopically, its tissue was composed of non-organized and spindle-shaped cells exhibiting atypical nuclei, which were divided up by branching vessel and collagen bundles. Immunohistochemical staining showed that this tumor was negative for CD117, CD99, CD68, cytokeratin, calretinin, desmin, epithelial membrane antigen, F8 and S-100, but positive for CD34, bcl-2, α-smooth muscle actin and vimentin. The patient presented no evidence of recurrence during follow-up. SFT arising from abdominal cavity can be diagnosed by histological findings and immunohistochemical markers, especially for CD34 and bcl-2 positive cases.

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.

[Solitary fibrous tumour of the pleura: about five cases]

BACKGROUND

Pleural solitary fibrous tumour (PSFT) is a rare, usually benign tumour, with unpredictable behaviour.

PATIENTS AND METHODS

Five cases of PSFT were diagnosed in our department over a 12-year period from January 1999 to December 2010. Clinical, radiological, histological, therapeutic and follow-up information were provided in all cases.

RESULTS

Our series comprised four men and one woman. The mean age of the patients at presentation was 55 years. All patients were symptomatic. Radiologic investigations showed a pleural lesion with a mean size of 10.6cm ranging from 3 to 17cm. Histologic diagnosis was made from resected parietal pleura in three cases and visceral pleura in two cases. The histologic features were suggestive of malignancy in two cases and benign in three cases. Immunohistochemical study showed that the tumour cells expressed vimentin, CD34, CD99 and Bcl2. Complete resection was obtained in all patients. The evolution was marked in the two patients with malignant PSFT by the recurrence of the tumour after 6 and 21 months respectively. Both died from the condition. The three patients with a benign form are disease-free after 3, 11 and 2 and half years of follow-up.

CONCLUSIONS

PSFT is rare tumour, the diagnosis of which is based on histologic investigations. These tumours require long-term monitoring due to the possibility of local recurrence and malignant transformation.

Solitary fibrous tumor: an update on the spectrum of extrapleural manifestations

Solitary fibrous tumor (SFT) is a rare tumor initially believed to be a benign localized pleural tumor of mesothelial origin. Over the past few years, the literature on this tumor has grown tremendously. The tumor is now reported in diverse bodily locations, and recognized to have a wider range of clinical and radiological features. The most common extrapleural sites of the tumor are the orbits and the extremities. Tumors are often well-circumscribed masses, and vary in size from 1 cm to over 30 cm. The admixture of histological components in the tumor, namely, fibrous tissue, cellular components, and highly vascularized areas consisting of numerous closely packed small to medium-sized blood vessels, influence the imaging appearances of the tumor. On magnetic resonance imaging (MRI), the diagnosis of solitary fibrous tumor is suggested by a well-circumscribed mass that has smooth margins, and focal or diffuse hypointense signal on T2-weighted imaging due to fibrous content in the tumor. SFTs demonstrate strong focal or diffuse contrast enhancement due to the highly vascularized areas in the tumor.

[Primary malignant solitary fibrous tumor/hemangiopericytoma of the parotid gland]

Solitary fibrous tumor (SFT) was first described in the pleura by Lietaud in 1767; later in 1870, Wagner described the localized nature of this type of tumor and Klemperer and Rabin classified pleural tumors into two types: diffuse mesotheliomas and localized mesotheliomas. Recent years have seen the redefinition of this neoplasm, due to better technology; it is now proven that this neoplasm may have multiple different extrapleural origins including the head and neck regions. This diversity of locations is related to the particular mesenchymal histogenesis of SFT which allows its development from very unusual sites such as the salivary glands (SGs). In this particular site, this neoplasm is very infrequent and most of reported cases refer to benign disease, with just one case informed so far of primary malignant SFT.

Solitary fibrous tumors of the pleura: results of surgical treatment and long-term prognosis

OBJECTIVE

We sought to define the long-term outcome of surgically treated solitary fibrous tumors of the pleura.

METHODS

We performed a retrospective review from December 1972 through December 2002.

RESULTS

There were 84 patients (39 men and 45 women) with a median age of 57 years (range, 34-83 years). Forty-six patients were symptomatic. Surgical resection included pulmonary wedge excision in 62 patients, lobectomy in 4 patients, segmentectomy in 2 patients, chest wall resection in 3 patients, isolated pleural resection in 7 patients, and chest wall resection with pulmonary wedge excision, lobectomy, or pneumonectomy in 3, 2, and 1 patients, respectively. Tumors were polypoid in 57 patients, sessile in 20 patients, and intrapulmonary in 7 patients. Histopathology was benign in 73 and malignant in 11 patients. Nine (82%) patient with malignant tumors and 37 (54%) patients with benign tumors were symptomatic (P = .11). The median tumor diameters for malignant and benign tumors were 12.0 and 4.5 cm, respectively (P = .001). Operative mortality and morbidity occurred in 3 (3.6%) and 7 (8.1%) patients, respectively. Median follow-up in survivors was 146 months (range, 23-387 months). Median survival for patients with benign and malignant tumors was 284 and 55 months, respectively, and 5-year survival was 88.9% and 45.5%, respectively (P = .0005). Eight (9.5%) patients had recurrent solitary fibrous tumors of the pleura. Recurrences were malignant in 6 and benign in 2 patients. Localized chest recurrences occurred in 3 patients, all of whom had reresection, with 2 patients again having recurrence.

CONCLUSION

Resection of benign solitary fibrous tumors of the pleura carries an excellent prognosis. Larger tumors are more likely to be malignant. Both benign and malignant tumors can recur. Although prolonged survival after resection of malignant tumors is possible, recurrence is common.

[Solitary fibrous tumour of the pleura: five cases]

Solitary fibrous tumours are unusual mesenchymatous tumours, most often found on the pleura. The authors report five cases hospitalised between 1998 and 2003. With the greatest occurrence in the fifth decade, they are often accidentally found but sometimes associated with a paraneoplastic syndrome such as refractory hypoglycaemia. The diagnosis is based on computed tomography and complete surgical resection is the best treatment. Adjuvant therapy is proposed for the histologically aggressive forms. Because of the possibility of local or distant recurrence and malignant transformation, long-term monitoring is strongly recommended.

Solitary fibrous tumor of the pleura: an analysis of 13 cases

BACKGROUND

Solitary fibrous tumor of the pleura is a rare soft-tissue tumor. In search of appropriate diagnosis and treatment methods, we present our experience with 13 patients.

METHODS

The medical charts of 13 patients treated during the last 5 years were reviewed, as well as pathological records, including immunohistochemical stains. Follow-up data were obtained. In addition, a literature review with regard to treatment and clinical outcome was performed.

RESULTS

Our series consisted of four men and nine women with a mean age of 47 years. Two were diagnosed before operation with ultrasonography-guided core needle biopsy. All patients underwent primary surgical treatment, and four of them were resected by video-assisted thoracic surgery. Seven tumors were malignant and the other six were benign. Immunohistochemical staining showed nestin was positive in three malignant solitary fibrous tumors of pleura (3/7), which were negative for CD34. Except for one, all patients were followed-up for 3 to 35 (mean, 14.5) months. Among them, one patient experienced a recurrence and one patient died of brain metastasis.

CONCLUSION

Ultrasonography-guided core needle biopsy combined with immunohistochemical analysis might be a safe and rapid method to provide a confirmatory diagnosis before resection. For smaller, pedunculated tumors, video-assisted thoracic surgery could be a powerful and useful approach. We speculate that CD34-negative and nestin-positive might be a malignant marker for solitary fibrous tumor of pleura.

Dedifferentiated liposarcoma of the pleura mimicking a malignant solitary fibrous tumor and associated with dedifferentiated liposarcoma of the mediastinum: usefulness of cytogenetic and molecular genetic analyses

Dedifferentiated liposarcoma of the pleura is an extremely rare malignancy mimicking a variety of tumors, such as other sarcomas, mesothelioma, and malignant solitary fibrous tumor of the pleura. Liposarcoma of the pleura can be combined with mediastinal involvement, and in most cases it may be impossible to be certain where the primary tumor originated. In this report, we describe a very rare occurence of a dedifferentiated liposarcoma of the pleura in a 76-year-old woman associated with a distinct second dedifferentiated liposarcoma of the mediastinum. Histologically, the pleural tumor demonstrated spindle cells arranged in a fascicular pattern, whereas the mediastinal tumor was mostly adipocytic with small areas of spindle cells. Vimentin and protein S100 were focally expressed by the tumor cells. The differential diagnosis of the pleural mass included malignant solitary fibrous tumor. Cytogenetic analysis showed supernumerary ring chromosomes in the pleural tumor, as well as strong amplification of MDM2 and CDK4 genes in both tumors. Array comparative genomic hybridization showed amplifications of chromosome arms 6q, 12q, and 15q, shared by both tumors and strongly pointing to a common origin.

Obstructive jaundice caused by secondary pancreatic tumor from malignant solitary fibrous tumor of pleura: A case report

A 77-year-old man on systemic chemotherapy against postoperative bilateral multiple lung metastases of malignant solitary fibrous tumor of the pleura suffered from pruritus and jaundice. Blood examination showed elevated levels of hepatobiliary enzymes. Abdominal computed tomography showed a tumor with peripheral enhancement in the pancreatic head, accompanied with the dilatation of intra- and extra-hepatic bile ducts. He was diagnosed as having obstructive jaundice caused by a pancreatic head tumor. The pancreatic head tumor was presumably diagnosed as the metastasis of malignant solitary fibrous tumor of the pleura, because the findings on the pancreatic head tumor on abdominal CT were similar to those on the primary lung lesion of malignant solitary fibrous tumor of the pleura. The pancreatic tumor grew rapidly after the implantation of metallic stent in the inferior part of the common bile duct. The patient died of lymphangitis carcinomatosa of the lungs. Autopsy revealed a tumor that spread from the pancreatic head to the hepatic hilum. Microscopically, spindle-shaped cells exhibiting nuclear atypicality or division together with collagen deposition were observed. Immunohistochemically the pancreatic head tumor cells were negative for staining of α-smooth muscle actin (α-SMA) or CD117, but positive for vimentin, CD34 and CD99. These findings are consistent with those on malignant solitary fibrous tumor of the pleura. We report the first case of obstructive jaundice caused by a secondary pancreatic tumor from malignant solitary fibrous tumor of the pleura.

Localized fibrous tumors (LFTs) of the pleura: clinical data, asbestos burden, and syntactic structure analysis applied to newly defined angiogenic/growth-regulatory effectors

This study was performed to add clinical data, to introduce new markers, and to perform syntactic structural analysis on localized fibrous tumors (LFTs) of the pleura. The material comprised clinical data and processed sections obtained from 36 patients. The results achieved from quantitative imaging techniques and syntactic structure analysis were correlated with clinical data, including patients' habits (smoking), asbestos exposure, survival, and tumor recurrence. The disease caused increasing chest pain and dyspnea in 47% of patients. Exposure to asbestos was noted in 13 out of 36 patients, whereas smoking posed no major risk factor. Two patients developed a recurrent tumor after 8 and 42 months, respectively; none of the other patients died of this tumor disease within the follow-up period of maximal 212 months. The cases were clearly discriminated from mesotheliomas by the marker profile. Frequent expression of accessible ligands for endogenous lectins galectins-1 and -3, the expression of the angiogenic macrophage migration inhibitory factor (MIF), and the dense vascularization intimate a functional relationship. The proliferation index (Nv) was computed to be 1.6% in line with the balance of galectin expression. Abnormal p53 was expressed in only 19.4% of the cases. The diagnosis of LFT can be aided by quantitative assessment of vimentin, CD34, MIF, vascularization, and proliferation. Considering the galectin network, differential expression was noted with preference to effectors limiting growth and aggressiveness.

Patterns of Recurrence and Long-Term Survival After Curative Resection of Localized Fibrous Tumors of the Pleura

BACKGROUND

Localized fibrous tumors of the pleura (LFTPs) are uncommon thoracic neoplasms with variable malignant potential that were previously classified as benign presentation of mesothelioma. We investigate the clinical presentation, recurrence patterns, and long-term survival of patients undergoing curative resection of LFTPs.

PATIENTS AND METHODS

Thirty-four patients underwent resection of LFTPs in the present study. There were 20 women and 14 men with a median age of 59 years (range, 35-81 years). The malignant potential of the tumor was estimated through histologic assessment of the degree of cellularity, mitotic activity, and nuclear pleomorphism. Patients' clinical outcomes were correlated to pathologic findings.

RESULTS

Seventeen patients (50%) were symptomatic, and 7 tumors (21%) were considered malignant by histologic characteristics. Ipsilateral pleural recurrence remote to the original tumor site occurred in 6 of these patients with malignant microscopic characteristics at a mean of 9 months after resection. Repeated resection was accomplished in 3 of these patients (range, 3-8 repeat operations). There have been no recurrences among the other 27 patients with benign histologic features, and 31 patients remain alive at a median follow-up of 34.5 months.

CONCLUSION

Histologic characteristics are helpful in estimating the risk of recurrence among patients with LFTPs. Close surveillance is recommended for patients with malignant histologic characteristics. Local recurrence is common without evidence of systemic spread among such patients. Surgical resection is definitive therapy; however, patients with tumors with histologic atypia require close postoperative observation because of the frequency of locoregional recurrence.