Solitary fibrous tumor of the orbit: Morphological, cytogenetic and molecular features

Clinician's approach for spectrum of orbital diseases: An overview

Purpose

To study the varied clinical presentation and outcome of management of orbital diseases and to ascertain the concordance of FNAC with histopathology.

Materials and Methods

This is a prospective interventional study wherein each patient's clinical presentation was noted. Outcome of management was evaluated based on symptomatic relief, regression of signs, noting any intraoperative or postsurgical complication, recurrence, and cosmetic result in terms of surgical scar.

Results

Neoplasia was commonest 33/76; (43.42%), followed by infective and inflammatory conditions 21/76; (27.63% cases), thyroid-associated orbitopathy accounting for 12/76 cases (15.78%), whereas cystic lesions and vascular malformations were 4/76 (5.26%) each. Other disorders constituted a mere 2.65%. Proptosis was the commonest mode of presentation. It was seen in seventy out of seventy-six patients (92.1%). In 86.3% of the cases, there was successful surgical outcome. Of 22 surgically managed cases, recurrence was noted in three cases (13.6%). 90% concordance was seen with histopathology in cases where FNAC was done prior to surgery for diagnosing nature of disease.

Conclusions

Majority of orbital and adnexal conditions can be provisionally diagnosed based on imaging; however, an adjunct invasive investigation such as FNAC or biopsy may be required. In the present study, in seven cases (9.2%) FNAC was needed, whereas in two cases (2.63%) biopsy was needed. A definitive diagnosis was confirmed by histopathology in 22 surgically managed cases and by excision biopsy in two. 22/76 (28.94%) of the cases needed surgical treatment, and other cases required conservative or palliative approach.

Fate and Management of Incompletely Excised Solitary Fibrous Tumor of the Orbit: A Case Series and Literature Review

PURPOSE

There is an imperfect correlation between the histology and behavior of solitary fibrous tumor (SFT). In addition, recurrence is common, and dedifferentiation may occur over time. Preferred primary treatment is intact excision, but friable pseudocapsules and tenacious attachments can thwart this goal in the crowded, visually sensitive orbit. This study addresses the fate and appropriate management of incompletely excised orbital SFT.

METHODS

Among a single surgeon's 7-case experience with orbital SFT, 3 cases involved incomplete primary excision, either before (2 cases) or after (1 case) referral. We reviewed the clinicopathologic data in these 3 cases, with follow-up intervals of 18, 21, and 52 years after initial presentation. We reviewed the English-language literature on SFT, with special attention to evolving nomenclature, orbital involvement, recurrence, malignant transformation, and management options.

RESULTS

Benign versus malignant designations of SFT vary with histological and behavioral criteria. Approximately 150 orbital cases have been reported. Published rates of primary malignancy and recurrence across all histologic categories are 6% to 12% and 30% to 37%, respectively. We identified 43 well-documented recurrences (range, 6 months-33 years; median, 3 years) and 10 cases of histological dedifferentiation (range, 14 months-33 years). Because of SFT's rarity and needed follow-up intervals, the value of adjuvant therapy is not yet proven. In follow up of 18, 21, and 52 years after initial presentation, our 3 cases with incomplete excision showed either no recurrence (Case 1) or no morphological dedifferentiation (Cases 2, 3).

CONCLUSION

A treatment algorithm is predicated on the completeness of surgical excision and histological features. However, we recommend case-by-case multidisciplinary decisions in a tumor-board setting.

Orbit Solitary Fibrous Tumor: A Proposed Risk Prediction Model Based on a Case Series and Comprehensive Literature Review

Solitary fibrous tumors (SFTs) of the orbit are rare. In order to further characterize the clinical and pathologic features of solitary fibrous tumor arising at this anatomic site, 12 cases of orbital SFTs were analyzed in conjunction with a review of 263 cases reported from the English literature in order to develop a risk prediction model. SFTs of the orbit were equally distributed between males (n = 5) and females (n = 7) with a mean patient age of 46.8 years (median 44.5 years; range 18-76 years) at initial diagnosis. The patients typically presented with swelling or mass around the orbit, with proptosis (n = 10), ptosis (n = 5), and visual changes (n = 6). Tumors were orbital (n = 10) or upper eyelid (n = 2). Mean tumor size was 2.5 cm (median 2.6 cm). Microscopically, the tumors were characterized by cytologically bland spindle cells with patternless growth, hypocellular and hypercellular areas, variable amounts of collagen, and ectatic, branching blood vessels. By immunohistochemistry, all cases had a strong nuclear STAT6 expression. All patients were initially managed with excision or biopsy, three with presurgical embolization. The two patients with biopsy only had persistent disease (mean 37.2 months), but a third patient developed distant bone metastasis at 86.9 months. Overall mean follow-up was 73.1 months: 9 patients are alive or dead without disease (mean 77.9 months), two patients with persistent disease, and one patient with metastatic disease at last follow-up (102 months). Incorporating cases sufficiently reported in the literature, a risk prediction model based on age > 45 years, tumor size > 3 cm, tumor necrosis, mitoses of > 4/2 mm², moderate to high cellularity, and moderate to severe pleomorphism allows for risk stratification for the development of local recurrence and distant metastasis. In conclusion, orbital SFTs are rare, but can be reliably diagnosed based on the presence of characteristic morphologic features and STAT6 immunohistochemistry. Orbital tumors tend to show a higher frequency of local recurrence than distant metastasis, which can be predicted by a risk stratification model unique to orbital tumors. With late disease common, long term clinical follow-up is recommended.

Solitary fibrous tumor involving urinary bladder: a case report and literature review

Solitary fibrous tumor (SFT) is a rare fibroblast stroma tumor involving the mediastinum and pleura. We herein describe an SFT of bladder which is extremely rare and review 29 similar cases in the last decades. We present a case of a 52-year-old male patient who suffered from urinary urgency and frequency for 12 months. Non-contrast computed tomography (CT) showed a slightly high density calcified mass with 70 mm × 61 mm in diameter. Contrast-enhanced CT demonstrated the mass was slightly enhanced. Cystoscopy revealed a huge mass with flat surface. Histopathological review of the biopsy specimens could not confirm the diagnosis. Partial cystectomy was then performed and the diagnosis of SFT was confirmed by immunohistochemistry. The patient is doing well at 12 months follow-up without recurrence and metastasis. In conclusion, the diagnosis of SFT involving bladder should combine clinical presentation and imaging features. Complete surgical resection is the primary method and long-term follow-up is necessary.

Role of Fine Needle Aspiration Cytology as a Diagnostic Tool in Orbital and Adnexal Lesions

Purpose:

To evaluate the role of fine needle aspiration (FNAC) as a diagnostic tool in cases of orbital and ocular adnexal masses. Cytological findings were correlated with histopathological diagnosis wherever possible.

Methods:

FNAC was performed in 29 patients of different age groups presenting with orbital and ocular adnexal masses. Patients were evaluated clinically and investigated by non-invasive techniques before fine needle aspiration of the masses. Smears were analyzed by a cytologist in all cases. Further, results of cytology were compared with the histopathological diagnosis.

Results:

The age of patients ranged from 1 to 68 years (mean: 29.79±19.29). There were 14 males and 15 females with a male to female ratio of 0.93:1. Out of 29 cases, 26 aspirates were cellular. Cellularity was insufficient in three (10.34%) aspirates. Out of 26 cellular aspirates, 11 were non-neoplastic while 15 were neoplastic on cytology. Subsequent histopathologic examination was done in 21/26 cases. Concordance rate of FNAC in orbital and ocular adnexal mass lesions with respect to the precise histologic diagnosis was 90%.

Conclusion:

When properly used in well-indicated patients (in cases where a diagnosis cannot be made by clinical and imaging findings alone), FNAC of orbital and periorbital lesions is an invaluable and suitable adjunct diagnostic technique that necessitates close cooperation between the ophthalmologist and cytologist. However, nondiagnostic aspirates may sometimes be obtained, and an inconclusive FNAC should not always be ignored.

Ocular adnexal (orbital) solitary fibrous tumor: nuclear STAT6 expression and literature review

PURPOSE

To report the clinico-pathological features of solitary fibrous tumor occurring in the ocular adnexa (OA) in a single center. To assess the presence of NAB2-STAT6 genes fusion in OA solitary fibrous tumor detected by nuclear overexpression of STAT6.

METHODS

Retrospective study including orbital and OA solitary fibrous tumors treated between 2006 and 2014 in our center. The clinical, radiological, and histopathological findings were evaluated. STAT6 expression was assessed by immunohistochemistry.

RESULTS

Five patients were identified and presented with a chronic OA mass. The tumors were radiologically well delimited, highly vascularized and without bone erosion. All the patients underwent complete surgical excision. Pathological examination confirmed solitary fibrous tumor in all cases. All tumors demonstrated a nuclear expression of STAT6. There were no recurrences, with a mean follow-up of 5 years after surgery. Our review demonstrated that proptosis was the most common presentation occurring in 60 % of the cases. In the ocular adnexa, adverse histological criteria were found in 19.7 % of the tumors, and recurrences were observed in 48 % of these cases. Thirty-six percent of patients presented at least one local recurrence, and metastastic spread was found in 2.4 % of the cases. Tumor-related death was described in two cases.

CONCLUSION

Ocular adnexal SFT are rare and usually present as a chronic orbital mass with proptosis. In the OA, solitary fibrous tumor demonstrates STAT6 nuclear expression, as documented in other locations. Recurrences are unusual and metastasis exceptional. Initial surgical resection should be complete in order to avoid recurrence.

STAT6 rabbit monoclonal antibody is a robust diagnostic tool for the distinction of solitary fibrous tumour from its mimics

Recurrent NAB2-STAT6 gene fusions have recently been identified in solitary fibrous tumour by next generation sequencing. Our aim was to examine the sensitivity and specificity of STAT6 immunohistochemistry for solitary fibrous tumour versus other morphologically similar soft tissue tumours. STAT6 expression was evaluated in 54 solitary fibrous tumours of various sites and 99 soft tissue tumours in the histological differential diagnosis. We used a rabbit monoclonal STAT6 antibody (1:100), which has not been reported by others, on formalin fixed, paraffin embedded whole sections and tissue microarray slides. Only nuclear staining of STAT6 was considered positive. Distribution of staining was scored as: 0 (no staining), 1+ (1-25%), 2+ (26-50%), 3+ (>50%). Intensity was scored as weak, moderate or strong. Nuclear STAT6 staining was present in all SFT cases tested (54/54, sensitivity 100%), regardless of histology, anatomical site or CD34 status. The majority of cases showed 3+ and strong staining. All tested cases of cellular angiofibroma (0/9), myofibroblastoma (0/10), spindle cell lipoma (0/10), benign fibrous histiocytoma (0/13), dermatofibrosarcoma protruberans (0/9), low-grade fibromyxoid sarcoma (0/7), schwannoma (0/8), desmoid-type fibromatosis (0/8), monophasic synovial sarcoma (0/11), malignant peripheral nerve sheath tumour (0/7), and mesenchymal chondrosarcoma (0/7) were negative for STAT6 (specificity 100%). Our study further supports the utility of STAT6 immunohistochemistry as an adjunct in the diagnosis of solitary fibrous tumour.

Endoscopic endonasal resection of medial orbital lesions with intraoperative MRI

BACKGROUND

Various approaches have been described and used for operating on lesions in the orbit. The approach selection is based on the pathology in the orbit and its exact location. This study was performed to evaluate the endoscopic endonasal approach (EEA) for orbital lesions and application of intraoperative MRI (iMRI).

METHODS

Since 2006, the present authors have performed 614 endoscopic endonasal procedures. iMRI was used in 409 of these cases. Three orbital lesions approached via the endonasal route with a minimum follow-up of 1 year were analysed.

RESULTS

EEA was used in one case of intraconal cavernoma, one extraconal cavernoma and one solitary fibrous tumour in the orbit. The lesion was located medially to the optic nerve in all cases. Radical resection was achieved and the patient's vision was improved in two cases with a preoperative visual field deficit. iMRI was useful in two cases. In one case intraoperative MRI helped to find an intraconal lesion; in the other case iMRI led to evacuation of haemostatic material and blood, which was causing compression in the orbit.

CONCLUSIONS

The EEA should be considered whenever a lesion in the orbit is located medially to the optic nerve. Excellent results were achieved. iMRI proved useful in selected cases.

Value of MR imaging in differentiation between solitary fibrous tumor and schwannoma in the orbit

BACKGROUND AND PURPOSE

Orbital SFT is a rare tumor, often misdiagnosed as orbital schwannoma preoperatively but with different prognosis and treatment. Our aim was to evaluate MR imaging features that might distinguish orbital SFT from schwannoma.

MATERIALS AND METHODS

MR imaging including DCE scanning was performed in 9 patients with SFT and 22 patients with schwannoma in the orbit confirmed by pathology. Location, shape, margin, signal intensity, homogeneity, enhancement pattern, ER, and TIC of the tumors were retrospectively evaluated.

RESULTS

There was a statistically significant difference between SFT and schwannoma in location and T2 signal intensity (P < .05). A statistically significant difference was also found regarding the enhancement pattern of the very high-signal-intensity areas shown on T2-weighted imaging and the type of TICs (P < .01).

CONCLUSIONS

MR imaging is useful in differentiating orbital SFT and schwannoma. The enhancement pattern of the very high-signal-intensity areas shown on T2-weighted imaging and the type of TICs on DCE MR imaging played an important role in differentiating orbital SFT from schwannoma.

Molecular biology of unreresectable meningiomas: implications for new treatments and review of the literature

Even though meningiomas are most often benign tumors, they can be locally invasive and can develop in locations that prevent surgical treatment. The molecular and biologic factors underlying meningioma development are only now beginning to be understood. Genetic factors such as mutations in the neurofibromatosis-2 gene and in chromosomes 1, 9, and 10 play important roles in meningioma development and may be responsible for atypical tumors in some cases. Cellular factors such as telomerase activation and tyrosine kinase receptor mutations may also play an important role. Finally, autocrine and paracrine factors including epidermal growth factor receptor, platelet-derived growth factor-1, and fibroblast growth factor have been implicated in the development of some tumors. Although the relationship between the various factors implicated in tumor development is unknown, understanding these factors will be critical in the treatment of malignant or surgically inaccessible tumors.

Solitary fibrous tumor of the head and neck

OBJECTIVE

The aim of this study was to review the reported cases of solitary fibrous tumor (SFT) in the head and neck and to evaluate this tumor regarding histologic features, treatment, and recurrence. SFT has been described in many extrapleural sites, including the head and neck. Uniform overexpression of CD34 differentiates SFT from other spindle cell neoplasms. SFT is a slow-growing neoplasm that can be successfully treated by complete excision. A rare malignant counterpart has also been described.

STUDY DESIGN

In this case series and review of published cases from English-language journals in the National Library of Medicine, we reviewed 142 cases of SFT reported in English-language literature and add 11 new cases. We compared the features reported in the previous publications of SFT from the head and neck with our series, including cases described as malignant or atypical SFT.

RESULTS

Four out of 9 cases with positive margins recurred, whereas only 1 out of 10 cases with atypical or malignant features recurred.

CONCLUSIONS

An important finding in SFT of the head and neck is that recurrence appears more related to incomplete excision than to microscopic grade.

New insights into the regulation of the actin cytoskeleton by tropomyosin

The actin cytoskeleton is regulated by a variety of actin-binding proteins including those constituting the tropomyosin family. Tropomyosins are coiled-coil dimers that bind along the length of actin filaments. In muscles, tropomyosin regulates the interaction of actin-containing thin filaments with myosin-containing thick filaments to allow contraction. In nonmuscle cells where multiple tropomyosin isoforms are expressed, tropomyosins participate in a number of cellular events involving the cytoskeleton. This chapter reviews the current state of the literature regarding tropomyosin structure and function and discusses the evidence that tropomyosins play a role in regulating actin assembly.

Oral solitary fibrous tumor: a cytogenetic analysis of tumor cells in culture with literature review

Solitary fibrous tumor (SFT) is an uncommon spindle-cell neoplasm of mesenchymal origin. Because the pathogenetic background of SFT is still controversial, cytogenetic analysis could help in tumor diagnosis and prognosis. In this study, cultured SFT cells from a lower lip lesion that presented characteristic immunopositivity for CD34, vimentin, CD99, and BCL2 showed a unique cytogenetic finding: 46,XX,inv(2)(p21q35),t(3;12)(q25;q15). To our knowledge, this is the third report of cytogenetic result of a case involving the oral cavity. The SFT cells in culture that maintained their immunohistochemical expression of diagnostic molecules, showed unique chromosomal changes previously unreported when compared with already documented ones. Our data suggest that the complicated pathogenetic nature of SFT is possibly tumor- or organ-related.

Orbital solitary fibrous tumor. Another rare case from Africa

Solitary fibrous tumor (SFT) of the orbit, initially thought to be rare, is being increasingly documented in the medical literature. We here present the case of a 37-year-old Nigerian man who presented with left sided painless, vision-sparing proptosis. Cranial computed tomography scan showed a globular, left medial, orbital extraconal mass. The mass was excised, en bloc, via a medial orbitotomy procedure aided by left ethmoidectomy. Surgery was uncomplicated and histology of the excised tissue was reported as compatible with SFT. There was also a strong and diffuse immunostaining with CD 34. At 6-month follow-up, the left-sided proptosis has completely regressed. To the best of our knowledge, this is the second case of orbital SFT to be reported in an African.

[Solitary fibrous tumor in the orbit. Case report and review of the literature]

BACKGROUND

Solitary fibrous tumor (SFT) is a mesenchymal neoplasm with a benign growth behavior. It was initially described in the pleura and has since been found in extrathoracic locations. In the orbital cavity, SFT is rare.

CASE REPORT

We report on a 94-year-old female patient with a large intraorbital SFT on the left side. Tumor growth over 7 years led to a severe exophthalmos with loss of vision. Imaging studies revealed a clearly delineated mass measuring 3x3.3x2.2 cm. Via an anterior orbitotomy approach, we performed an in toto resection. Histological examination, including immunohistochemical detection of CD34 antigen, confirmed the presence of SFT.

CONCLUSION

SFT is a rare differential diagnosis of orbital lesions and can be appropriately treated by surgical resection. When left untreated, complications such as loss of vision can occur.

Atypical presentation of a case of solitary fibrous tumor of the orbit

PURPOSE

To describe a rare case of solitary fibrous tumor of the orbit in a child, clinically misdiagnosed as arterious hemangioma.

METHODS

A nine-year-old child presented a hard-elastic palpable mass located in the right inferotemporal orbit. Computed tomography, orbital pulsed-wave Doppler and internal carotid artery angiography consented diagnosis of high-vascularization mass probably related to arterious hemangioma with feeder vessel arising from a branch of ophthalmic artery. The orbital mass was surgically removed.

RESULTS

The histological examination showed mesenchimal tumor, CD34 positive, related to solitary fibrous tumor of the orbit.

CONCLUSIONS

Solitary fibrous tumor of the orbit should be considered in the differential diagnosis of arterious hemangioma.

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.

Solitary fibrous tumor of the orbit: CT and MR imaging findings

BACKGROUND AND PURPOSE

Solitary fibrous tumor (SFT) is a rare spindle-cell neoplasm originating from mesenchymal fibroblast-like cells. The purpose of this study was to describe the CT and MR imaging features of SFTs in the orbit.

MATERIALS AND METHODS

We retrospectively reviewed CT and MR images in 6 patients (2 men and 4 women), aged 18 to 51 years, with SFT proved on histologic examination located in and around the orbit. All patients underwent CT (including dual-phase CT in 3), and MR imaging was obtained in 3. We evaluated the imaging findings with emphasis on the location, size, margin, internal architecture, and pattern of enhancement of the lesion.

RESULTS

All 6 lesions were found as a solitary, well-defined mass, ranging in size from 18 to 30 mm (mean, 24 mm). Three were located in the postseptal orbit, 2 in the lacrimal sac, and 1 on the lower eyelid. Compared with the cerebral cortex, all 3 lesions examined by MR imaging showed homogeneous isointense signal intensity on T1-weighted images and heterogeneous mixed isointense and hyperintense signal intensity on T2-weighted images. On visual inspection, all 6 lesions showed marked homogeneous (n = 4) or heterogeneous (n = 2) enhancement on postcontrast CT and MR images. In 3 patients examined with dual-phase CT, all lesions demonstrated rapid enhancement with early washout of contrast material.

CONCLUSION

SFT might be included in the differential diagnosis of soft tissue masses in the orbit, if one sees a markedly enhancing mass showing the similar characteristics to those of the internal carotid artery on postcontrast CT or MR images.

Caldesmon and the regulation of cytoskeletal functions

Caldesmon (CaD) is an extraordinary actin-binding protein, because in addition to actin, it also bindsmyosin, calmodulin and tropomyosin. As a component of the smoothmuscle and nonmuscle contractile apparatus CaD inhibits the actomyosin ATPase activity and its inhibitory action is modulated by both Ca2+ and phosphorylation. The multiplicity of binding partners and diverse biochemical properties suggest CaD is a potent and versatile regulatory protein both in contractility and cell motility. However, after decades ofinvestigation in numerous laboratories, hard evidence is still lacking to unequivocally identify its in vivo functions, although indirect evidence is mounting to support an important role in connection with the actin cytoskeleton. This chapter reviews the highlights of the past findings and summarizes the current views on this protein, with emphasis of its interaction with tropomyosin.

Solitary fibrous tumor of the oral cavity: the need for an extensive sampling for a correct diagnosis

BACKGROUND

Solitary fibrous tumor (SFT) is an uncommon but well-characterized soft tissue tumor that was first described as a pleural lesion and now is considered ubiquitous, having been detected at many extra-pleural sites (abdominal cavity, orbit, upper respiratory tract, and oral cavity). Histologically, SFT may show wide morphological variability of both its cellular and stromal components, which may lead to incorrect diagnosis especially when dealing with small incisional biopsies.

MATERIALS

We report on the clinical, morphological and immunohistochemical features of eight SFT occurring in the oral cavity.

RESULTS

Microscopically all eight tumors showed widely variable morphological features in terms of cellular density and stromal architecture, thus simulating benign fibrous histiocytoma, schwannoma, hemangiopericytoma or low-grade sarcoma in distinct areas of the same lesion. Among these eight cases, five had been diagnosed as SFT, two as benign fibrous histiocytoma and one as low-grade sarcoma.

CONCLUSIONS

In consideration of the heterogeneous morphological appearance of SFT, inaccurate sampling of the mass may lead to misdiagnosis and inappropriate treatment. Therefore, an accurate histological examination of multiple tissue sections is advised, along with the use of appropriate immunostains.