Solitary fibrous tumor of the orbit: a clinicopathologic entity that warrants both a heightened awareness and an atraumatic surgical removal technique

PURPOSE

To describe the first confirmed case of solitary fibrous tumor in Saudi Arabia and in the Middle East, and to illustrate a surgical technique for atraumatic complete removal.

METHODS

A retrospective interventional case report that describes the first confirmed case of solitary fibrous tumor in the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia.

RESULTS

The clinical presentation, computed tomography (CT) findings, and histopathological, immunohistochemical and electron microscopic findings to confirm the diagnosis, as well as the cryodissection surgical technique for atraumatic removal of solitary fibrous tumor used, are described.

CONCLUSIONS

Solitary fibrous tumor should be considered in the differential diagnosis when a patient presents with unilateral proptosis and a well-circumscribed, intensely enhancing mass on CT imaging. Because of the risk of malignant transformation, surgical en bloc removal with minimal tissue damage is the treatment of choice. This may be achieved by means of cryo-extraction via a minimally invasive orbitotomy.

Clinicopathological Features of Solitary Fibrous Tumors of the Pleura: a Case Series and Literature Review

We assessed the clinicopathological features of solitary fibrous tumors of the pleura in a case series comprising 30 patients (20 women, 66.6%) with a mean age of 58.39 years. Forty-five percent of the cases were asymptomatic. In 70% of the cases the tumors arose in the visceral pleura. Twenty percent presented multiple tumors, a finding that was associated with intrapulmonary localization and malignant behavior (P<.0001) Histology revealed low cell density in 15% of the cases, moderate density in 50%, and high density in 35%; further findings showed atypia in 45% of the cases, necrosis in 25%, and hemorrhage in 15%. More than 4 mitoses per 10 high-power fields were noted in 30% of the cases. Immunohistochemistry results were positive for vimentin in all cases; cells were CD34+ in 85% of the cases, BCL2+ in 65%, and CD99+ in 40%. Findings for keratin and protein S100 were negative in all cases. Malignant biological behavior (local recurrence and metastasis) was observed in 4 cases, 2 of which were CD34-. Solitary fibrous tumors of the pleura are uncommon neoplasms with unpredictable biological behavior; follow-up should therefore be based on early detection of recurrence or metastasis.

Solitary fibrous tumor of the liver

We report a new case of benign solitary fibrous tumor (SFT) of the liver. A 65-year-old man presented to our unit with upper right abdominal discomfort. On examination abdominal distension was present and palpation showed a large firm mass in the right hypochondrium and epigastrium. The patient's past medical history was not significant and laboratory tests were normal. Ultrasonography and computed tomography showed a large tumor, 20 cm in diameter, in the right lobe of the liver. An extended right hepatectomy was performed. The tumor measured 30 x 28 x 14 cm and weighed 4725 g. Microscopic evaluation showed a benign SFT of the liver with tumor cells typically positive for vimentin and CD34. The postoperative course was uneventful, and the patient is alive 30 months after surgery. This is a rare neoplasm of mesenchymal origin that occasionally involves the liver in adult patients. Most SFTs are benign, but some may have malignant histological features and recur locally or metastasize. Because of their rarity, overall experience has not been significant and little has been published concerning this tumor, Including the present one, 28 cases have been reported in the English literature. Surgery is the mainstay of treatment. Little can be said about the benefits of adjuvant radiochemotherapy in these patients. As SFT of the liver is often a benign neoplasm, chemotherapy or radiotherapy should not be necessary, and should be reserved for when resection is incomplete and/or histological examination reveals features of malignancy. Surgeons must be aware of SFT of the liver, and this neoplasm should be included in the differential diagnosis of a single large hepatic mass.

[Solitary fibrous tumor: a clinico-morphological and immunohistochemical study]

Solitary fibrous tumor is a rare neoplasm which may occur at any site although it is more frequent in the pleura, mediastinum and lung. The study used 4 cases of tumor localization in the pleura and orbit. Three cases presented as a "hemangiopericytic" variety of spindle cells; there were numerous giant cells in orbit tumor. Solitary fibrous tumor revealed enhanced expression of vimentin, CD34, bel-2 and CD99. Expression of S-100, desmine and non-striated muscle actin was found in few cells in some cases. Such features as large size (over 10 cm), necrosis, high cellularity, nuclear polymorphism and high mitotic index (more than 4 mitoses within 4 visual fields, at high magnification) were used as malignancy criteria:. Tumor histological pattern of "hemangiopericytic" variety could be reliably identified thanks to immunohistochemical procedure.

Solitary fibrous tumour of the soft tissue of the face: a case report

INTRODUCTION

Solitary fibrous tumour (SFT) is a rare mesenchymal neoplasm described first in the pleura. Recently, SFTs have been found in various extra-serosal locations, including the head and neck region.

CASE PRESENTATION

We report a case of SFT originating from the periorbital region of the face. Preoperative cytological examination by fine needle aspiration biopsy diagnosed a mesenchymal tumour. The patient underwent surgical resection. The mass was completely resected. Definitive histopathologic and immunohistologic examination confirmed the diagnosis of SFT.

DISCUSSION

The rare localisation in extrapleural sites and the multiplicity of histological patterns can explain the difficulty in arriving at a definitive diagnosis in SFT. Usually, SFT is a benign tumour, although malignant variants exist. Clinical behaviour is unpredictable and recurrence or malignant transformation can also occur, especially in cases with macroscopically or microscopically invaded margins. Complete surgical excision and long follow-up is therefore always recommended. The recent increase in reports of extrapleural SFT indicates that this rare tumour should be included in the differential diagnosis of soft tissue head and neck tumours.

Myxoid solitary fibrous tumour of the axilla

Mostly occurring in pleura, solitary fibrous tumour is an unusual soft tissue neoplasm. Solitary Fibrous Tumour with abundant myxoid stroma represents a rare morphologic subtype of the already uncommon tumour. We report a myxoid solitary fibrous tumour of the soft tissue in a 42-year-old man. The patient presented with a large, movable, nontender mass at the right axilla. The MRI showed a well-defined tumour with increased signal after gadolinium injection. During surgery, the mass was found to be closely associated with the axillary vein. The tumour was completely excised. Pathological and immunohistochemical examinations identified the mass as a myxoid solitary fibrous tumour. The patient was free of tumour recurrence at 18-month follow-up. The rare tumour in an uncommon location makes the diagnosis difficult. Complete excision and long-term follow up are recommended.

[Solitary fibrous retroperitoneal tumour: report of two cases]

Solitary fibrous tumours are benign tumours, described for the first time by Klemperer and Rabin in 1931. They are mesenchymal tumours which usually arise in the pleura, while retroperitoneal sites have been rarely described. The authors report two cases of very large retroperitoneal tumours in two men aged 58 and 47 years, respectively, who consulted for abdominopelvic vaulting associated with gastrointestinal and urinary disorders. Ultrasound-guided biopsy suggested the diagnosis preoperatively in one case. In the light of these cases, the authors present a review of the main extrapleural sites described to date, as well as the most characteristic radiological, histological and immunohistochemical features in order to facilitate the diagnosis.

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.

Microvessel density and HIF-1alpha expression correlate with malignant potential in fibrohistiocytic tumors

Angiogenesis is a central process in the growth of solid tumors. Hypoxia-inducible factor-1alpha (HIF-1alpha) is an oxygen-dependent transcriptional activator, which plays a crucial role in tumor angiogenesis. However, involvement of HIF-1alpha has never been studied in so-called fibrohistiocytic tumors, such as dermatofibroma (DF), dermatofibrosarcoma protuberans (DFSP) and malignant fibrous histiocytoma (MFH). We analyzed the extents of angiogenesis in relation to the expression levels of HIF-1alpha in 26 DF, 13 DFSP and 23 MFH cases. MFH showed significantly higher microvessel density (MVD) compared with DF and DFSP. Immunohistochemically, HIF-1alpha-positive cases constituted 31%, 15% and 98% of DF, DFSP and MFH, respectively, indicating significantly higher HIF-1alpha expression in MFH compared with DF and DFSP. Furthermore, MFH cases expressing high levels of HIF-1alpha showed significantly higher MVD than those with low levels of HIF-1alpha. Thus, higher levels of angiogenesis and HIF-1alpha expression are both closely associated with the malignant potential in so-called fibrohistiocytic tumors, and HIF-1alpha is possibly involved in angiogenesis in MFH.

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.

Recurrence and increased proliferation rate of a solitary fibrous tumor in the central nervous system--case report and review of the literature

Meningeal solitary fibrous tumors (SFTs) were at first estimated as rare benign tumors which can be cured by total resection. To date, only 37 patients with intracranial SFTs have been reported. Therefore, the natural history of this tumor entity needs more enlightenment. The authors report a case of a 77-year-old female in whom a SFT with infiltration of the transversal sinus was subtotally resected. After a short time, interval tumor recurrence was seen, 2 years and 6 months later second surgery was performed. Immunohistologically, in both specimens typical features for SFT with positivity for CD34, vimentin and BCL-2 and negative for epithelial membrane antigen was seen. No signs for malignancy occurred in the second resection. Notably the MIB-1 index increased from 1 to 5%. In conclusion, consequent long-time follow-up for SFTs are necessary, especially after incomplete tumor resection.

Solitary fibrous tumour of the oral cavity with histological features of aggressiveness

We operated on a 65-year-old woman and removed a solitary fibrous tumour from her oral mucosa. Microscopically we found marked atypia, abundant necrosis, increased number of mitotic figures (>4 in 10 high-power fields) and hypercellularity. The tumour cells were strongly stained for CD34. There has been no recurrence after 18 months.

Recurrent solitary fibrous tumour in the cerebellopontine angle

Solitary fibrous tumours (SFT) of the central nervous system are rare. They resemble meningioma in clinical presentation, imaging features and appearance at surgery. Schwannoma, hemangiopericytoma and other spindle cell mesenchymal neoplasms should also be considered in the differential diagnosis. Although the histogenesis of this tumour is still debated, strong CD34 reactivity of the tumour cells suggests that SFT is mesenchymal. We present the clinical, radiological, and pathological features of an SFT located in the cerebellopontine angle (CPA). A 55-year-old female presented with 6 months of headache. The MRI scan showed a contrast enhancing ovoid mass in the left CPA. At craniotomy, the tumour was completely resected. Histolopathological diagnosis was of meningioma. Three years later, the symptoms recurred and an MRI scan demonstrated tumour recurrence. A repeat craniotomy was performed and the lesion was again completely excised. Tumour morphology on histopathology and immunoreactivity for CD34 of the tumour cells supported the diagnosis of SFT. Review of the original tumour also disclosed immunoreactivity for CD34. Ki67 labeling indices were less than 1% in both tumours.

Benign solitary fibrous tumour of the pleura: a clinical review and report of six cases

Primary tumours of the pleura are commonly divided into two major categories: diffuse and localised. Whereas the diffuse variant is known for its association with asbestos and its poor outcome, the localised one is rare and remains a subject of controversy. Electron microscopy and immunohistochemistry have recently demonstrated that these tumours are of mesenchymal rather than mesothelial origin, and therefore the term "localised mesothelioma" was abandoned. Such tumours are now called solitary fibrous tumours of the pleura (SFTP). The Authors describe a series of 6 cases of benign solitary fibrous tumours of the pleura, surgically treated over the period 1982-2000.

[Paratesticular fibrous pseudotumours]

Paratesticular fibrous pseudotumours are a rare form of benign tumour with a slow course and a difficult preoperative diagnosis. The objective of treatment is to ensure optimal testis conservation, which is possible when the diagnosis is made on intraoperative frozen section examination. The authors report a case of diffuse fibrous pseudotumour in a 23-year-old man. In the light of this case and a review of the literature, they discuss the diagnostic and therapeutic aspects of these tumours.

Spinal Solitary Fibrous Tumors: A Series of Four Patients: Case Report

OBJECTIVE AND IMPORTANCE:

Intraspinal solitary fibrous tumors, which are rare mesenchymal tumors, have previously been reported as case reports. We review our experience and, to our knowledge, the first small institutional series with respect to clinical presentation, diagnosis, surgical management, pathohistological analysis, progression-free survival, and long-term outcome.

CLINICAL PRESENTATION:

In this retrospective review, four patients (three male and one female) ranging in age from 17 to 59 years (mean, 38.5 yr) had spinal solitary fibromas located throughout the spinal canal. Three tumors were located in the thoracic region and one in the cervical spine. All patients presented with pain and paresthesia. Two patients had an associated spinal deformity. All had gross total resection as confirmed by postoperative imaging studies.

INTERVENTION:

All four patients underwent surgical treatment for spinal solitary fibromas. None of these patients underwent irradiation or chemotherapy after surgery at our center; therefore, outcome was attributed to surgery alone. There were no surgical deaths, and the 5-year actuarial survival rate was 100%. At the most recent follow-up examination, neurological function was stable or improved in 90% of patients.

CONCLUSION:

Patients with solitary fibrous tumors have a long survival. These tumors have an indolent course, and radiotherapy or chemotherapy seems to be unnecessary.

Ultrastructural spectrum of solitary fibrous tumor: a unique perivascular tumor with alternative lines of differentiation

Eight tumors diagnosed as solitary fibrous tumor (SFT) of the oral cavity were studied. Histologic spectrum was entirely comparable with the extrapleural SFT of other sites. One tumor had glomus tumor-like foci. Immunohistochemical results confirmed most of the previous observations, indicating characteristic expression of vimentin, CD34, bcl-2, and CD99. Factor XIIIa and alpha-smooth muscle actin were less commonly reactive and a very few cells were faintly positive for factor VIII-related antigen and Ulex europaeus agglutinin 1. All were essentially negative for S-100 protein, desmin, CD31, and CD68. In stark contrast to the conclusive immunoprofile, ultrastructural investigation of six tumors demonstrated considerable cellular heterogeneity. Other than fibroblasts, perivascular undifferentiated cells and pericytes predominated, but endothelial cells were regularly present. There was a distinctive proliferation of pericytic cells in four tumors, one of which had glomoid foci of myopericytes. The extreme increase in number of Weibel-Palade bodies occurred in voluminous capillary endothelium. Occasional single and clustered cells with consistent features of endothelium showed intracytoplasmic lumen formation. Such composite cells constituted an integral segment of richly vascularized SFT. Myofibroblastic form smooth muscle differentiation was present in only a minority of cells. From phenotypic analysis by electron microscopy, SFT may originate from a unique, perivascular multipotent mesenchyme sharing with its lineage with pericytes, fibroblasts, and infrequently, endothelium. Consequently, morphological features of SFT may become diversely varied by whether predominantly constituent cells are undifferentiated, pericytic or fibroblastic in nature.

Solitary fibrous tumor of the orbit: a case report

Solitary fibrous tumor is a very rare neoplasm affecting the head and neck. We present a case located in the orbit in which clinical, pathological and surgical features are reviewed.

Solitary fibrous tumor: report of a case with an unusual presentation as a spindle cell parotid neoplasm

BACKGROUND

Initially described as a pleural tumor, solitaryfibrous tumor of the parotid gland (SFT) is rare and has been reported at a wide range ofanatomic sites. Although cases of SFT arising in the parotid gland have been previously described, a review of the literature failed to reveal cytology-based reports of this entity.

CASE

A 42-year-old man presented with a right parotid mass that had gradually enlarged over 3 years. He was otherwise asymptomatic. Fine needle aspiration biopsy of the mass showed a hypercellular smear composed of spindle cells in both clusters and isolated forms, with ovoid nuclei, evenly distributed chromatin, inconspicuous nucleoli and scant to moderate cytoplasm with focally wispy, collagenous, intercellular material. The background was hemorrhagic, without chondromyxoid matrix or inflammatory cells. There was no evidence of a myoepithelial component. A diagnosis of spindle cell neoplasm was rendered. Histologic examination of the total parotidectomy specimen revealed a SFT arising in the parotid gland. The diagnosis was supported by immunohistochemical studies.

CONCLUSION

SFT is a well-circumscribed neoplasm composed of short, spindled, plump cells with scanty cytoplasm growing in a haphazard or "patternless" pattern. Tumor cells are intimately admixed with collagenous stroma. Hemangiopericytomalike vessels are frequently seen. Although SFT rarely occurs in the salivary gland and a definitive diagnosis based on cytologic preparations alone is difficult, the diagnosis of SFT can be considered when cytologic examination reveals a hypercellular smear composed of isolated, cohesive clusters of spindled, fibroblastlike cells associated with a collagenous component in ahemorrhagic background. The preoperative magnetic esonance image findings of a highly vascular neoplasm support the diagnosis.

Fibroblast phenotype plasticity: relevance for understanding heterogeneity in "fibroblastic" tumors

Cellular transformations, reflecting phenotypic plasticity, characterize embryonic life, would-repair, physiological adaptation, and neoplasia. Fibroblastic tumors show a range of cellular differentiation, which can be rationalized in terms of phenotypic plasticity of the "normal" fibroblast. In this paper, the various kinds of fibroblast transformation are discussed, and some insights provided into the molecular mechanisms involved. Comparable molecular events may take place in neoplastic fibroblasts to produce the heterogeneous tumors nevertheless identified as fibroblastic. The following transformations are discussed: histiocytic, and fibrohistiocytic tumors; adipocytic, and lipogenic tumors; myofibroblastic, and myofibroblastic tumors. A definition of the fibroblast is required. This consists of spindle-cell morphology, vimentin-staining, and abundant rough endoplasmic reticulum. Transformation to histiocytic, lipogenic and myofibroblastic phenotypes requires the development of lysosomes, lipid droplets and lamina, and peripheral myofilaments and fibronexuses respectively. These occur in non-malignant transforming (transdifferentiating) fibroblasts, and also in tumors identified as fibrohistiocytic, lipogenic and myofibroblastic. The molecular basis of the myofibroblast transformation is probably the best studied. It is driven primarily by transforming growth factor beta. Investigations into the mechanisms of differentiation in normal fibrobiasts could prove fertile ground for defining comparable differentiation in tumors. In this respect, there are very few publications on the presence of growth factors in tumors or tumor-like lesions. There is, however, increasing investigation into gene expression and gene products in tumors, which bear on the differentiation process. Ultimately, our understanding of the molecular events controlling differentiation in cancer will lead to control, cure and prevention.