Thoracic solitary fibrous tumor: clinical and pathological diversity

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.

Explaining the Invisibility of Asbestos-Related Diseases in the Taiwan Workers' Compensation System

Occupational asbestos exposure was prevalent in Taiwan, but asbestos-related diseases (ARDs) have rarely been recognized. We conducted in-depth face-to-face interviews with 16 patients with ARDs. All of them had worked in industries known for high asbestos exposure. However, only three patients had filed workers' compensation (WC) claims, and of them, only two patients were approved. Reasons for the low compensation rate of ARDs could be divided into institutional barriers related to the flaws of the WC system and non-institutional barriers related to the knowledge status, causal interpretation, and social situations of individual workers. The Labor Occupational Accident Insurance and Protection Act passed in April 2021 has responded to the under-compensation of occupational diseases. However, the new act's effects toward improving the recognition of ARDs remain questionable. Our findings indicated that additional efforts are needed to remove non-institutional barriers hindering workers' ability to ensure their compensation rights.

Targeting-intratumoral-lactic-acidosis transcatheter-arterial-chemoembolization for non-islet cell tumor hypoglycemia secondary to a liver metastatic solitary fibrous tumor: A case report and literature review

Doege-Potter syndrome is a rare paraneoplastic syndrome characterized by non-islet cell tumor hypoglycemia secondary to a solitary fibrous tumor. Doege-Potter syndrome always presents with recurrent fasting hypoglycemia, which can occasionally be life-threatening. The best choice of treatment for Doege-Potter syndrome and solitary fibrous tumor is complete resection. However, when it is unfeasible, local-regional treatment can be used as a palliative therapy. Herein, we report a case of a 46-year-old man with Doege-Potter syndrome that occurred secondary to the liver and pancreatic metastatic solitary fibrous tumors. After he received six rounds of targeting-intratumoral-lactic-acidosis transcatheter-arterial-chemoembolization (TILA-TACE) treatment in our hospital, his hypoglycemia was clinically cured, and the liver metastatic tumor was well controlled. We suggest that TILA-TACE can be considered when curative resection is unfeasible for metastatic liver solitary fibrous tumors to help a patient obtain further surgery opportunities.

Solitary Fibrous Tumors Arising from Bilateral Ovaries: A Case Report and Review of the literature

BACKGROUND

A solitary fibrous tumor (SFT) is a distinct mesenchymal neoplasm. It was originally described as a tumor localized to the pleura but was later reported in several other anatomic sites and exhibited a wide spectrum of histological features. Owing to its rarity, the diagnosis of extrapleural SFT is challenging and requires an integrated approach comprising specific clinical, imaging, histological, and immunohistochemical findings.

CASE PRESENTATION

Herein, we report the imaging findings of a rare case of SFT arising from bilateral ovaries confirmed by surgical excision and histological examination. No adjuvant radiotherapy or chemotherapy was given to the patient, and she was disease-free with no evidence of recurrence or metastasis at the 96-month postoperative follow-up. Although it mostly follows a favorable course, SFT is notoriously difficult for prognostication because of its propensity for late relapse or even metastases in 10-39% of cases.

CONCLUSION

Close follow-up is recommended because of the limited information on its long-term behavior.

Solitary fibrous tumour of mediastinum: an often asymptomatic neoplasm

Solitary fibrous tumours (SFTs) are rare neoplasms derived from mesenchymal cell lines. They are often asymptomatic, follow an indolent growth pattern and are more often benign than malignant. Here, we present a case of a very large, asymptomatic mediastinal SFT in an otherwise healthy man. A 67-year-old Irish man was referred for workup of an asymptomatic murmur. Auscultation of the lung fields revealed diminished breath sounds on the right side. Chest X-ray identified a 20 cm mass localised within the thorax. CT of the thorax confirmed a pleural based, solid lesion with no local invasion. CT-guided core biopsies were reported as consistent with SFT. Primary excision of the lesion was undertaken via median sternotomy. Histological examination confirmed a diagnosis of SFT. The patient remains well at this time. Primary excisive surgery is a safe and effective treatment modality for SFTs.

A Comprehensive Review on Solitary Fibrous Tumor: New Insights for New Horizons

Simple Summary

Solitary fibrous tumor (SFT) is a malignant condition that exhibits different clinical behaviors ranging from low to high aggressive SFT, with dedifferentiated SFT (DD-SFT) being the fastest-growing subtype. Even when surgery alone provides curation rates above 60%, recurrences do occur in a fraction of patients where surgery is unable to provide disease control. Among the systemic therapeutic options, antiangiogenic compounds have shown higher efficacy than chemotherapy by indirect comparisons. Furthermore, rotating different antiangiogenics, at the progression time, has been shown to be effective. The exception is DD-SFT since it is resistant to antiangiogenics but can respond to chemotherapy. This comprehensive review also analyzes the underlying molecular components that play a key role in SFT origin and aggressiveness. The discovery in 2013 of anomalous fusion genes between NAB2 and STAT6 was determinant to increase the knowledge on the molecular drivers in SFT that could be potential targets for future therapies.

Abstract

Solitary fibrous tumor (SFT) is a rare mesenchymal, ubiquitous tumor, with an incidence of 1 new case/million people/year. In the 2020 WHO classification, risk stratification models were recommended as a better tool to determine prognosis in SFT, to the detriment of “typical” or “malignant” classic terms. The risk for metastasis is up to 35–45%, or even greater, in series with a longer follow-up. Over the last few decades, advances in immunohistochemistry and molecular diagnostics identified STAT6 nuclear protein expression and the NAB2–STAT6 fusion gene as more precise tools for SFT diagnosis. Recent evidence taken from retrospective series and from two prospective phase II clinical trials showed that antiangiogenics are active and their sequential use from first line should be considered, except for dedifferentiated SFT for which chemotherapy is the best option. Since the fusion transcript driver’s first description in 2013, new insights have been brought on key molecular events in SFT. This comprehensive review mainly focuses on the superior efficacy of antiangiogenics over chemotherapeutic agents in SFT, provides the current knowledge of key molecules that could co-drive the SFT behavior, and suggests new target candidates that deserve to be explored in preclinical and clinical research in SFT.

Solitary Fibrous Tumors of the Pleura

Solitary fibrous tumors of the pleura (SFTP) are rare neoplasms. We present a case of a 53-year-old female presenting to the pulmonary clinic after an incidental finding of a right-sided chest wall tumor on a chest X-ray. A CT scan of the chest showed a pleural-based right upper lung mass; a biopsy of the mass was consistent with a solitary fibrous tumor.

The Diagnosis of Pleural Tumors Other Than Mesothelioma

CONTEXT

- Pleural pathology has been dominated by discussions relating to the diagnosis, prognosis, etiology, and management of malignant mesothelioma. However, there exists a diverse group of other neoplasms that involve the pleura; the most common by far is metastatic carcinoma, usually of pulmonary origin. Other metastatic tumors of varied histogenesis do occur but are less common. Primary pleural neoplasms other than diffuse malignant mesothelioma are either uncommon or rare and have received less attention.

OBJECTIVE

- To provide a review of those diverse tumors that can involve the pleura other than mesothelioma in order to facilitate their accurate diagnosis.

DATA SOURCES

- Review of relevant literature published via PubMed and other search engines.

CONCLUSIONS

- A wide variety of tumors can involve the pleura. In most cases, the approach of considering the morphologic features with appropriate immunohistochemistry, in the correct clinical context, allows for a confident diagnosis. For a number of those soft tissue tumors that are well recognized in the pleura, such as solitary fibrous tumor, desmoid-type fibromatosis, synovial sarcoma, and epithelioid hemangioendothelioma, novel markers now exist based on an understanding of the individual tumors' molecular characteristics. Primary pleural lymphomas are rare with poor prognosis. They represent localized specific diffuse large B-cell lymphomas, with either post-germinal center B-cell or plasma cell lineage, arising in the context of either immunodeficiency or immune sequestration and with viral infection.

Endoscopic Transnasal Resection of Solitary Fibrous Tumor in the Optic Canal

BACKGROUND

Tumors extending into the optic canal can cause progressive visual impairment because of optic nerve compression. Prompt surgical resection is often necessary. When the tumor is located medially in the optic canal, endoscopic transnasal surgery provides a safer, less invasive alternative to a transcranial approach.

CASE DESCRIPTION

We recently encountered a case of small solitary fibrous tumor in the optic canal causing rapid visual deterioration. The radiographic findings of preoperative imaging studies were compatible with those of meningioma; however, unlike meningioma, bleeding from the tumor was profuse during the operation. The endoscopic transnasal approach was effective for handling the highly vascularized tumor in this delicate region, and gross total removal was achieved with postoperative gradual improvement in his visual function. Nevertheless, the tumor recurred after 6 months, and re-resection was performed using the same surgical corridor, followed by adjuvant radiotherapy.

CONCLUSIONS

Endoscopic transnasal surgery is a valuable option for aggressive lesions in the optic canal. Although the efficacy of radiotherapy for solitary fibrous tumor remains controversial, it should be considered when the tumor shows progressive features.

Primary intrapulmonary solitary fibrous tumours

Due to the extreme rarity of primary intrapulmonary solitary fibrous tumours (SFTs), their clinical course, imaging characteristics, diagnosis, treatment and prognosis are poorly understood. The present study therefore assessed the diagnosis and management of primary intrapulmonary SFTs and systematically reviewed previously reported cases in the literature. A total of 5 patients who underwent resection for primary intrapulmonary SFTs were enrolled in the present study and their clinical course, tumour characteristics, management and survival were assessed in this retrospective study. Relevant studies regarding primary intrapulmonary SFTs were searched using PubMed and tumour characteristics, clinicopathologic features, therapeutic strategy and survival outcomes were reviewed. Of the 5 cases, all were males, with a mean age of 57.6 years (range, 37-68 years). All patients were asymptomatic and were identified incidentally on routine computed tomography examination. A total of 3 patients underwent thoracotomy and 2 patients underwent video-assisted thoracoscopic surgery. All tumours were completely resected. Postoperative haemorrhage occurred in 1 patient and he received surgical intervention for haemostasis. The average hospital stay was 15 (4-22) days, and no mortality occurred. The mean length of the postoperative follow-up was 37.6 (1-67) months. One patient was lost to follow-up, and 4 patients were asymptomatic. A total of 19 studies were identified from database searches. They included a total of 45 patients: Twenty-three males and 22 females (mean age, 59.4 years; range, 7-81 years). A total of 12 patients were asymptomatic, and pain and coughing were the major symptoms. Five, one, two, four, and 17 tumours occurred in the right upper lobe, right middle lobe, right lower lobe, left upper lobe and left lower lobe, respectively. A total of 39 patients underwent surgery, 1 patient underwent radiotherapy, and 1 patient underwent radiofrequency ablation. A total of 22 patients were followed up and the mean length of the postoperative follow-up was 48 (1-168) months. One patient was diagnosed with chest wall metastases, and 5 patients succumbed to mortality. To conclude, primary intrapulmonary SFTs are extremely rare and typically identified incidentally. The present findings indicated that the left lower lobe was the most common site location and complete surgical resection is a safe and effective treatment.

Solitary fibrous tumor of the lung: a case report

Solitary fibrous tumors (SFTs) are relatively rare neoplasms that commonly occur in the pleura. The pathological feature of SFTs is a proliferation of spindle-shaped cells in interlacing or storiform fascicles. SFTs appear to derived from pluripotential submesothelial cells, but not the covering mesothelium. SFTs distinctively show diffuse staining for CD34 but lack staining for smooth muscle markers. We herein report a relatively rare case of a 68-year-old male patient without symptoms, who underwent resection for what was considered to be SFT.

An unusual pathology with an undefined etiology:solitary fibrous tumors of the pleura

BACKGROUND/AIM

The aim of the present study was to evaluate the etiology and clinical and pathological behavior of solitary fibrous tumors of the pleura (SFTPs), as well as the most appropriate surgical approach and the results of long-term follow-up of this condition.

MATERIALS AND METHODS

Clinical and long-term follow-up records of 14 patients who had surgery for SFTP between 2001 and 2014 were reviewed retrospectively. Etiological factors, diagnostic procedures, and clinical courses and outcomes for these patients were studied.

RESULTS

Of the 14 patients, 8 were male (57%) and 6 were female (43%) patients. The mean age was 54.14 ± 10.35 (41-75) years. There was no remarkable common etiological factor. Preoperative diagnosis was achieved only in 2 patients. Predominant symptoms were cough and chest pain. Complete resection was achieved in all patients. Video-assisted thoracic surgery (VATS) was performed in 8 patients. All but one patient were classified as having benign SFTP. The mean follow-up was 58.5 ± 41.4 (10-132) months and no recurrence was noted in the follow-up.

CONCLUSION

These rarely seen tumors of the pleura are usually benign and asymptomatic and their preoperative diagnosis is difficult. Clinical and pathological behavior is still unpredictable and the treatment consists of complete resection. Minimally invasive techniques such as VATS are recommended for surgery if the tumor size is appropriate.

Solitary Fibrous Tumors of the Pleura of the Thorax: CT and FDG PET Characteristics in a Tertiary Referral Center

This study was conducted to describe the characteristics of a solitary fibrous tumor of the pleura (SFTP) on chest CT, and FDG PET. Furthermore, we analyze the prognosis of SFTP using large data confirmed in a tertiary referral hospital. From January 1997 to March 2012, 41 patients (21 males and 20 females; median age: 59 yr; age range: 27-85 yr) who were pathologically diagnosed with SFTP were consecutively examined. The CT findings, including the size, shape, homogeneity, and anatomic location (chest wall, intrapulmonary/fissure space, diaphragm, and mediastinum) of the SFTP, the F-fluorodeoxyglucose positron emission tomography (FDG PET) findings, and the histopathology findings were evaluated. Most of the patients had a mass-type (70.7%), oval/elliptical (80.5%), and homogeneous (70.7%) SFTP with a median diameter of 6.0 cm (range: 1-17). The most common anatomic location was the chest wall (43.9%), followed by the intrapulmonary/fissure space (22.0%), diaphragm (22.0%), and mediastinum (12.3%). For all the 9 patients, the mean maxSUV was 2.9 (SD = 1.16; range: 1.2-4.9) on FDG PET. The malignant SFTP (median: 3.6, range: 2.5-4.9) showed more hypermetabolic than benign SFTP (median: 2.0, range: 1.2-3.1) (P = 0.049). Through familiarity with the various features of the SFTP with regard to its size and location on the preoperative CT and FDG PET, we can add this rare pleural neoplasm to the differential diagnosis of other more common conditions. Moreover, an appropriate treatment choice can be made.

Extrathoracic location and "borderline" histology are associated with recurrence of solitary fibrous tumors after surgical resection

BACKGROUND

Most solitary fibrous tumors (SFTs) are cured by complete resection, but many recurrent and metastatic SFTs do not respond to treatment and are fatal. Malignant histology, defined by England's pathologic criteria, is strongly associated with recurrence, but some benign SFTs still behave aggressively. Several studies have suggested that extrathoracic SFTs have a worse prognosis. We reviewed thoracic and extrathoracic SFTs from our institution to determine if extrathoracic location is associated with recurrence, independent of malignant histology.

METHODS

With IRB approval, we retrieved patient pathology reports from the Johns Hopkins Surgical Pathology database between 1991 and 2011 and included 83 SFT patients in our analysis. Patient history and outcomes were obtained from the medical record and primary care physicians. Predictors of recurrence were analyzed by univariate and multivariate analysis and survival determined by the Kaplan-Meier method.

RESULTS

Of the 83 patients, 59 had extrathoracic SFTs in neurologic (n = 24), extremity or head/neck (n = 13), or visceral/intraabdominal (n = 22) sites. A total of 74 SFTs were classified benign and 9 as malignant. Of the 14 recurrences, 13 occurred in extrathoracic SFTs; only 7 were classified as malignant. Multivariate analysis confirmed that malignant histology had the strongest association with recurrence, but extrathoracic location also independently predicted recurrence. A total of 20 benign SFTs possessed 1 or more of England's criteria but to an insufficient degree for malignant classification. These "borderline" SFTs were more likely to recur than benign SFTs without these features.

CONCLUSIONS

Extrathoracic and "borderline" SFTs with any of England's criteria have a higher risk of recurrence.

Immunohistochemical endothelial markers: a review

A relatively large number of new endothelial markers that can assist in the diagnosis and classification of endothelial and vascular neoplasms have become available over the past few years. The expression of these markers, however, differs considerably among the various tumors. A selection of markers that have potential diagnostic utility or are of current interest among pathologists are reviewed and compared with some of the more traditional markers that have been employed in diagnostic pathology.

Thoracic malignant solitary fibrous tumors: A population-based study of survival

INTRODUCTION

This study characterizes the overall survival (OS) and cause specific survival (CSS) of patients with thoracic malignant solitary fibrous tumors.

METHODS

Eighty-two patients with malignant solitary fibrous tumors of the lung, pleura or mediastinum, diagnosed from 2001-2007, were retrospectively analyzed using the population-based Surveillance, Epidemiology, and End Results database.

RESULTS

Among 77 patients with available staging information, 42% (n=32) had localized disease, 31% (n=24) had regional disease extension (without nodal involvement) and 27% had regional-nodal (n=2) or distant (n=19) metastases. Cancer-directed surgery was performed in 85%; radiation was performed in 16%. The 1-year, 5-year and median OS were 87%, 49% and 4.6 years respectively. The 1-year, 5-year and median CSS were 89%, 61% and 5.7 years respectively. Less advanced stage and undergoing cancer-directed surgery were favorable prognostic factors. For localized, regional and distant stage the median OS was: not reached at 6.3 years, 4.4 years and 2.0 years respectively (P=0.021); the median CSS was not reached at 6.3 years, 5.0 years and 2.4 years (P=0.068). For patients undergoing versus not undergoing surgery, the median OS was 4.9 vs 0.9 years (P=0.053) and median CSS was 5.7 vs 0.9 years (P=0.011). Tumor size was not significant.

CONCLUSIONS

From a population-based analysis of patients with thoracic malignant solitary fibrous tumors, stage and cancer-directed surgery had the greatest impact on OS and CSS. While being amenable to surgery likely reflects more indolent disease and/or better performance status and cardiopulmonary function, the significantly favorable impact of surgery also likely reflects a therapeutic benefit.

A case of the large retroperitoneal solitary fibrous tumor

A rare autopsy case of the extremely large retroperitoneal solitary fibrous tumor is reported. A 52-year-old female with a huge abdominal distention was found dead at home. She showed remarkable emaciation. The autopsy revealed a huge retroperitoneal tumor weighing 11.9kg (36×30×20cm in size), which occupied the entire intraperitoneal cavity. Histologically, the tumor consisted of spindle parenchymal cells with fibrous tissues. Immunohistochemically, CD34 was positively stained, whereas S-100, smooth muscle actin, and factor VIII were negative. Her cause of death was diagnosed as emaciation due to the compression of the entire intestine by the tumor. This is a rare case of the extremely large retroperitoneal solitary fibrous tumor, which caused the occasional intestinal obstruction. This disease should be considered in the differential diagnosis of retroperitoneal large tumors that cause accidental deaths in forensic autopsies.

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.

Intrapulmonary solitary fibrous tumor

Solitary pulmonary nodules are sometimes detected by routine chest radiography. Although many of them are suspected to be benign tumors following noninvasive examinations including computed tomography and positron emission tomography, it is difficult to diagnose them accurately. This report presents a rare case of a solitary fibrous tumor located in the lung that could not be diagnosed preoperatively. More information must be accumulated concerning such rare cases of intrapulmonary solitary fibrous tumors.

Surgically cured hypoglycemia secondary to pleural solitary fibrous tumour: case report and update review on the Doege-Potter syndrome

The association of paraneoplastic hypoglycemia [Doege-Potter syndrome] and finger clubbing [Pierre-Marie-Bamberg syndrome] with pleural solitary fibrous tumour is rare. We present a previously unpublished but typical example of this rare occurrence together with a detailed updated literature review of previously published cases of pleural SFT discussing the histopathology of SFT; pathophysiology of the hypoglycemia and finger clubbing; treatment and outcome of pleural SFT. The patient, a 57-year-old African male was admitted at our hospital with recurrent episodes of hypoglycemia. He was found to have digital clubbing and decreased breath sounds in the right lower chest but no other significant clinical findings. His insulin level measured during an episode of hypoglycemia was undetectable. Chest radiograph and CT-scan revealed a lobulated mass in the right chest which was diagnosed to be SFT on histology. Surgical excision of the mass resulted in cure of the hypoglycemic episodes and rapid regression of the clubbing. Less than 65 cases of pleural SFT manifesting with hypoglycemia with or without finger-clubbing have been published in the English literature. The mean diameter of these tumours manifesting with hypoglycemia is 20 cm, 54% being benign while 42% were malignant. They predominantly present in the 6th-8th decade, average age of 64 years and a slight male preponderance at 58%. Complete surgical resection remains the most important predictor of clinical outcome in terms of recurrence and metastases, while providing instant cure for the hypoglycemia and rapid resolution of the finger clubbing.

Primary pleural neoplasia: entities other than diffuse malignant mesothelioma

CONTEXT

Overwhelmingly, the most common neoplasm involving the pleura is metastatic carcinoma. In contrast, diffuse malignant mesothelioma occurs relatively rarely; however, it is nonetheless the most common neoplasm primary to the pleura. Metastatic carcinoma and diffuse malignant mesothelioma each have their own prognostic and therapeutic characteristics. Other primary pleural neoplasms occur uncommonly or rarely, with their own prognostic and therapeutic characteristics.

OBJECTIVE

To review primary pleural neoplasms other than diffuse malignant mesothelioma, to better ensure correct diagnosis and optimal assessment of prognosis and treatment.

DATA SOURCES

Literature review and primary material from the authors' institutions.

CONCLUSIONS

A nonexhaustive group of uncommon to rare benign and malignant primary pleural neoplasms--other than diffuse malignant mesothelioma--are presented, of which one must be aware in order to maintain an appropriate index of suspicion to include them in the differential diagnosis of a pleural tumor.

Large Solitary Fibrous Tumour of the Pleura: Analysis of Six Cases

BACKGROUND

A large solitary fibrous tumour of the pleura (SFTP) is a very rare occurrence. The aim of this study was to retrospectively review the clinical characteristics, surgical treatment and outcome of patients with a large SFTP operated on in our General Thoracic Surgery Unit.

METHODS

We conducted a retrospective analysis of the clinical records of six patients who underwent surgery for a huge SFTP between 1998 and 2004.

RESULTS

Six patients (four men and two women, mean age 73.3 years) with a large SFTP (mean diameter 20.3 and mean weight 1265 g) underwent surgery during this period with full excision of the tumour. Five tumours were excised together with the implantation basis, and in one case extended resection with pneumonectomy was performed. The presentation symptoms resolved in all cases after surgery.

CONCLUSIONS

Despite the huge size of these tumours (giant SFTP), surgical resection is an acceptable method of treatment in elderly patients with low morbidity and mortality rates.

Intrapulmonary Solitary Fibrous Tumor Diagnosed by Immunohistochemical and Genetic Approaches: Report of a Case

Although solitary fibrous tumors (SFTs) of the pleura are not uncommon, intrapulmonary SFTs are extremely rare. A 72-year-old woman was admitted to our hospital for an investigation of an enlarging intrapulmonary tumor. Because a definitive diagnosis could not be readily established, a pulmonary wedge resection under video-assisted thoracic surgery was performed. Grossly, the tumor was white, well circumscribed, and separate from the pleural surface. Histologically, it consisted of spindle cells proliferating in a vague fascicular pattern, with many dilated capillaries, and intermingled glandular components. These findings suggested a differential diagnosis that included SFT and nonchondromatous pulmonary hamartoma. On immunohistochemical analysis, the spindle cells showed a strong positive reaction to the CD34 antigen. Interphase fluorescent in situ hybridization revealed an absence of HMGA-1 and -2 translocations. These results supported a diagnosis of SFT. A genetic approach may therefore be useful in the differentiation of SFT from nonchondromatous hamartoma.

[Solitary fibrous tumor of the visceral pleura of the right lung base]

Solitary fibrous tumors are relatively frequent. They may occur throughout the body. About 20% of tumors develop in the thorax, out of which vast majority is localized on its wall. Within thorax, they usually originate from pleura, most frequently the visceral one. Authors present a 67- year old male in whom the tumor was diagnosed during the investigation for dyspnea. During operation, solitary, well circumscribed, firm, ruber-like tumour, 11 x 10 x 9 cm in diameter, covered with serosa, arising from the visceral pleura of the base of the right lung was easily excised. The classical histological and immunohistochemical examinations confirmed the diagnosis of benign fibrous tumor. Postoperative recovery was uneventful. Preoperative symptoms disappeared.

Tumor to tumor metastasis: report of two cases and review of the literature

Tumor-to-tumor metastases are uncommon. The most frequent donor tumor is lung cancer, while renal cell carcinoma (RCC) is by far the most common recipient. In this report, a carcinoma of the uterine cervix metastasizing to an RCC and a urothelial carcinoma of the urinary bladder metastasizing to a solitary fibrous tumor of the pleura are described. No similar cases have been found in the accessible literature. These cases are discussed and the findings are correlated with the data of the literature.

Solitary fibrous tumors of the pleura

Solitary fibrous tumor of the pleura is a mesenchymal tumor that has been increasingly recognized over the past few years. The tumor was initially described in the pleura, but it has been reported in many other sites lately. Although the majority of these tumors have a benign course, the malignant form still remains enigmatic. Indeed, the behavior of these tumors is often unpredictable and does not always correlate with histologic findings. In addition, benign tumors may remain unproblematic for several years before changing into a malignant form. In order to define more precisely the clinical behavior of solitary fibrous tumors of the pleura, we reviewed the literature with particular attention to the clinical presentation, histopathologic characteristics, and cytogenetic differentiation of these tumors. A staging system and an algorithm for the management and follow-up of these patients are proposed.

Solitary fibrous tumours of the meninges: case series and literature review

We report four new cases of meningeal Solitary Fibrous Tumour (SFT). Two patients presented with raised intracranial pressure from posterior fossa SFT, and the third developed hemiparesis and dysphasia due to a large lesion that originated in the left middle cranial fossa. These were successfully excised and the patients remain well at follow-up of between 1 and 3 years. The fourth patient, a 71-year-old man, suffered an intracerebral haemorrhage and later died from a malignant SFT that had invaded the falx cerebri, superior sagittal sinus, and brain. This is the first description of a locally aggressive meningeal SFT with multiple atypical histological features. The 31 previously reported cases of meningeal SFT are reviewed. They occur at all ages and may be relatively more common in the posterior fossa and spine. Intracranial SFT originate from the dura and are probably indistinguishable from meningiomas on imaging and at surgery. In contrast, approximately two-thirds of spinal SFT have no dural attachment. Histologically, SFT are spindle-cell neoplasms with a characteristic immunohistochemical profile of CD34, vimentin, and bcl-2 positivity. Data on outcome for patients with meningeal SFT are limited. At other sites, however, extent of resection is the most important prognostic factor, and invasion or metastasis can occur with histologically benign SFT. Meningeal SFT should, therefore, be excised as completely as possible and followed carefully in the long-term.

Malignant solitary fibrous tumor of the pleura with liposarcomatous differentiation

Pleural solitary fibrous tumors (SFTs) are uncommon tumors. Although these tumors have been well characterized, malignant pleural SFTs with liposarcomatous differentiation have not been reported. We report an unusual malignant pleural SFT intermixed with foci of well-differentiated liposarcoma. The patient was a 66-year-old, white man with a large, solid right pleural mass that measured 13.5 x 10.3 x 8.5 cm. The tumor was composed of spindle-shaped and plump cells embedded in dense collagenous stroma. The tumor cells were arranged in interlacing fascicles or in a patternless pattern. Marked nuclear atypia, a high mitotic rate (21 mitoses per 10 high-power fields), and areas of prominent necrosis were evident. In addition, numerous adipocytes mixed with typical lipoblasts were seen scattered throughout portions of the tumor. Immunohistochemistry revealed the tumor cells were strongly positive for CD34 and vimentin and negative for cytokeratin, desmin, smooth muscle actin (IA4), and S100. To the best of our knowledge, this case represents the first example of a malignant SFT with liposarcomatous differentiation.

Benign solitary fibrous tumor of the parietal pleura which invaded the intercostal muscle

A 29-year-old woman who underwent evaluation for a 3-month history of left-sided back pain proved to have a left pleural tumor accompanied by a bloody pleural effusion (cytological class II). Three years previously, a chest roentgenogram had been normal. The tumor originated from the parietal pleura at the level of the first three intercostal muscles and was excised completely in continuity with these muscles, including a margin of normal muscle. The tumor measured 15x12 cm and the pathologic diagnosis was benign solitary fibrous tumor; while the tumor invaded the intercostal muscles, no histologically malignant features were present. Long-term follow-up is planned because a possibility of local recurrence exists.