Head and neck solitary fibrous tumors: a rare and challenging entity

Reconstruction of Midface Defects after Radical Tumor Resection - a Rare Case Report of Solitary Fibrous Tumour of the Hard Palate

Introduction- Spindle cell neoplasm is a variant of squamous cell carcinoma. One of its subtypes is solitary fibrous tumor. Its occurrence in head and neck is very rare and rarer in hard palate. But if occurs, radical excision is the only choice as it has malignant potential but coverage of such large mid face defects imposes a challenge in front of a Plastic Surgeon as it demands both soft tissue coverage and skeletal support. Report of the case- A 33 year male presented to our department with swelling of left side face involving the anterior palate, maxilla, nose, and upper lip. With the help of the surgical oncology team, wide local excision of the neoplasm along with bilateral infrastructure maxillectomy, total rhinectomy, total upper lip resection and total hard palatectomy was done. This created large defect in the mid face which was covered with free anterolateral thigh flap. Biopsy was done which revealed the swelling as a solitary fibrous tumor of hard palate. All the margins were free of tumour. The flap settled well. Nostrils were secured with nasal stents. After 3 months, an expander was placed in forehead of the patient for future nasal reconstruction. After 3 months, nasal reconstruction was done using expanded forehead flap and costal cartilage. After 21 days flap detachment and insetting was done. White roll creation was also done. One more secondary procedure was done for flap thinning as patient had complain of nasal obstruction. After 6 months vascularised free fibula bone graft was introduced to reconstruct maxilla for future dental rehabilitation. The patient is in regular follow up and he is satisfied with the results. Discussion- Mid face defects involving perioral and nasomaxillar areas are very uncommon and require composite reconstruction. In such cases, microvascular free flap coverage is an irreplaceable option. Multiple stages might have to be done for further refinement. Conclusion- Reconstruction after oncological resection is always very demanding. With proper preoperative planning and skilled execution, the patient can be benefited functionally, aesthetically and psychosocially.

Solitary fibrous tumor of the parapharyngeal space: report of 2 cases and a literature review

The solitary fibrous tumor (SFT) is usually described as a lesion arising from the pleura. Rarely, it has been described in the parapharyngeal space (PS). This study aims to report two cases of SFT in the PS and to perform a literature review on this topic. Two patients undergoing surgical resection of a SFT in the PS, were reported. A literature review on SFT of the PS, was also performed. Two patients were analyzed. Both patients underwent surgical resection, followed by adjuvant radiotherapy, for SFT arising from the PS. The postoperative course was uneventful and both patients recovered well after the procedure. No recurrences were diagnosed during the followup. SFT of the PS is an infrequent entity. Surgical resection is the most used treatment, and adjuvant radiation should be considered in patients with recurrence risk factors or distant metastases.

A case report on a nasal and oral cavity involving large solitary fibrous tumor and comprehensive review of case literature

Solitary fibrous tumor (SFT) represents an uncommon spindle cell sarcoma predominantly situated within soft tissue, with a notably infrequent occurrence in the nasal cavity and paranasal sinuses. In this report, we present a case involving a middle-aged male with a sizable solitary fibrous tumor affecting both the nasal and oral cavities.

A review of solitary fibrous tumours of the orbit and ocular adnexa

Solitary fibrous tumour (SFT) is an uncommon spindle cell tumour of mesenchymal origin characterised by NAB2-STAT6 gene fusion. Although it was first described in the pleura, it can occur in connective tissue in any part of the body, but rarely presents in the orbit and ocular adnexa. SFT, which is part of the same disease spectrum as other fibroblastic tumours such as giant cell angiofibroma, haemangiopericytoma and fibrous histiocytoma, usually presents as a painless, slow-growing mass in any age group and generally follows a benign course, with a good prognosis after complete excision. However, malignant forms rarely occur. Even for benign tumours a more aggressive clinical behaviour is possible, with relentless infiltrative local growth, frequent recurrence following surgery, and malignant transformation with the potential for metastatic spread. Careful long-term follow-up is essential. The published literature on SFTs of the orbit and ocular adnexa is reviewed, and the aetiology, clinical presentation, epidemiology, radiological features, histopathology, immunohistochemistry, risk stratification, clinical management, and prognosis are discussed, reflecting on our own experience.

Solitary Fibrous Tumor of Hard Palate: A Case Report and Literature Review

Solitary fibrous tumor (SFT) is a mesenchymal tumor accounting for less than 2% of soft tissue tumors and has variable clinical behavior. It can arise in many anatomical locations of the body and in rare occasions in the oral cavity mostly in buccal mucosa and tongue. To date, a handful of such cases have been reported in the hard palate. We present a case of SFT in the hard palate of a 32-year-old man and describe the tissue morphology, immunohistochemistry workup, and follow-up together with literature review.

Solitary Extrapleural Fibrous Tumor in Salivary Glands: Our Experience-Case Series and Literature Review

(1) Background: Extrapleural solitary fibrous tumors (ESFTs) are rare oncological entities occurring in the head and neck, and even more so in the salivary glands. The clinical presentation and histologic features are usually unspecific, resulting in frequent misclassification. As an unusual tumor, ESTFs have an unpredictable clinical behavior. (2) Methods: We present two clinical cases referred to our Maxillofacial Surgery Unit for the onset of a symptomless mass involving, in one case, the parotid gland, and in the other case, the sublingual gland. (3) Results: Solitary fibrous tumors could be considered as neoplasms with intermediate biological behavior that are not entirely predictable on the basis of morphological features, as these are mostly still unknown. However, a few histologic, immunohistochemical, and imaging features, such as a hypodense signal at the T1 sequence in an MRI, or positivity for CD34, bcl2, and CD99, and the NAB2-STATS6 fusion gene, could be useful for an early differential diagnosis of ESTFs. (4) Conclusions: All patients were alive at follow-up with no evidence of disease. Surgical management should always be considered as the first choice for oncological radicality, and clinical behavior should always be defined with the help of the study of radiological and anatomopathological features.

A Large Solitary Fibrous Tumor of the Nasal Cavity and Paranasal Sinuses Involving the Anterior Frontal Fossa: A Case Report and Review of the Literature

The Solitary Fibrous Tumor (SFT) is a rare mesenchymal neoplasm that arises mainly from the pleura. The sinonasal tract is generally not affected by SFT, and less than 100 cases have been reported in the English literature to date. We report an extremely rare SFT of the nasal cavity and paranasal sinuses extending into the anterior frontal fossa through the floor of the anterior skull base. To our knowledge, this case is the fourth SFT of the sinonasal tract involving the anterior frontal fossa in the world. Meanwhile, the tumor, measuring 13 × 6 cm in images, is the largest SFT of the sinonasal tract compared to previously reported cases. Three surgical procedures, including a transcranial one, were performed for the patient to achieve complete removal of the tumor. The diagnosis of SFT was established primarily by immunohistochemical positivity for CD34, STAT6, and negativity for S-100 protein. We emphasize the possibility of recurrence in SFT, and close follow-up is necessary with the help of nasal endoscopy and imaging approaches.

Toward Better Understanding and Management of Solitary Fibrous Tumor

Solitary fibrous tumor (SFT) comprises a histologic spectrum of soft tissue neoplasms that are characterized by the unique NAB2-STAT6 gene fusion. Changes in diagnostic terminology and site-specific classification over the past few decades have resulted in a disjointed literature. Complete surgical excision with preservation of function remains the mainstay of treatment. New risk stratification systems including risk factors such as mitotic rate, age, tumor size, and presence of necrosis, among others, can be used to predict risk of recurrence or metastasis. Long-term follow-up after surgical resection is recommended. The clinical manifestations, diagnosis, management, and prognosis of SFT are reviewed here.

Solitary Fibrous Tumors of the Head and Neck: A Single-Institution Study of 52 Patients

Objective

To evaluate the clinicopathologic characteristics of head and neck solitary fibrous tumors and features that may predict tumor recurrence.

Study Design

Retrospective review.

Setting

University of California–Los Angeles Medical Center.

Methods

A single-center retrospective study was conducted on pathologically confirmed cases of head and neck solitary fibrous tumors between 1996 and 2021. Patient demographics, clinical course, and histopathologic features were evaluated. Recurrence-free survival was estimated via Kaplan-Meier analysis.

Results

A total of 52 patients were reviewed. The average patient age was 54.7 years (range, 15-89). The most common subsite was the orbit (53.8%, n = 28), but other involved areas included the nasopharynx, paranasal sinuses, and scalp. The median tumor size was 2.95 cm (range, 1.3-11.2). Strong STAT6 (100%) and CD34 (97.9%) expression was observed on immunohistochemistry. Almost all patients were initially managed with wide local excision; 82% of patients (n = 14) had positive margins on pathologic review; and 15% (n = 4) had recurrence at a median 28.5 months (range, 10-113). White patient race was the only significant predictor of tumor recurrence. Patient age (≥55 years), tumor size (≥4), high mitotic rate, and disease subsite were not associated with recurrence.

Conclusion

Head and neck solitary fibrous tumors demonstrate a significantly larger local recurrence rate as compared with their rate of metastasis. They can recur many years following initial therapy, warranting long-term surveillance and follow-up to assess for tumor recurrence.

Rare Case of Solitary Nasal Fibrous Tumor Eroding Skull-Base

Solitary fibrous tumor (SFT) is a spindle cell lesion, classified under mesothelial tumors. Involvement of the nasal cavity, paranasal sinuses, and nasopharynx is rare. We present an extremely rare case of SFT of nasal origin eroding the anterior skull base. Complete local excision is the treatment of choice in the head and neck SFT, and we successfully excised the tumor by endoscopic approach only. The patient followed an uneventful course without any evidence of recurrence on 8-months follow-up.

Solitary Fibrous tumor of Nasal cavity: A case report and review of literature

Introduction and importance

Solitary fibrous tumors (SFTs) involving the nasal cavity are extremely rare with few cases reported in the literature.

Case presentation

We present a case of SFT in a 90 year-old male complaining of a slow-growing mass prolapsing through left nostril. Nasal endoscopy and imaging exams revealed a mass occupying the entire left nasal cavity, pushing the nasal septum to the opposite side and extending up to the nasopharynx. Biopsy specimen examination reported sarcoma. The patient underwent complete surgical resection of the mass through left para-latero-nasal approach. Immuno-histochemical analyses confirmed the diagnosis of SFT. The patient has remained free of tumor 2 years after surgery.

Clinical discussion

Clinical and imaging features of SFTs of nasal cavity are not specific. A broad of differential diagnosis is associated with histopathologic features of SFTs. Therefore, immuno-histochemical analyses are crucial to confirm the diagnosis. Complete resection of the mass with clear margins is mandatory to minimize local recurrence.

Conclusion

SFTs of nasal cavity are very rare neoplasms which continue to pose challenges to practitioner. Pathological examination and mainly immunohistochemical studies are important to establish the diagnosis. Complete resection of the tumor is the key for good outcome.

•

Solitary fibrous tumors of nasal cavity are very uncommon neoplasms.

•

Clinical and imaging features are not specific.

•

Diagnosis is based on immunohistochemical analyses.

•

Malignant behavior cannot be predicted even in the absence of atypical histologic features.

•

Complete resection of the tumor with clear margins and long term surveillance after surgery are mandatory.

Profile of sphingolipid-related genes and its association with prognosis highlights sphingolipid metabolism in oral cancer

BACKGROUND

Sphingolipids are bioactive lipids that play a role in cancer development. However, the clinical role of sphingolipid (SPL)-related genes in oral cancer (OC) remains not fully understood.

OBJECTIVE

This study, aimed to examine the mRNA expression of 14 sphingolipid-related genes in oral cancer patients and their implication with clinicopathological features and prognosis.

METHODS

qPCR analysis was performed in 50 OC tissues and their matched surgical margins. Next, Kaplan-Meier, Cox regression, and Receiver operating characteristics (ROC) analysis were applied to evaluate the impact of sphingolipid-related genes expression on the prognosis of OC.

RESULTS

The genes SET, ACER3, SK1 and S1PR5 were predominantly up-regulated, while ABCG2, S1PR1, ABCB1 and SPNS2 were down-regulated in OC patients. Analyzing the Cancer Genome Atlas Head-Neck Squamous Cell Carcinoma (TCGA-HNSC) data, which are predominantly composed of OC samples, these genes displayed a similar profile. In OC patients, high levels of SK1 were associated with lymph node metastasis, extracapsular invasion, desmoplasia, locoregional relapse, and disease status. Low levels of SPNS2 were associated with lymph node metastasis, perineural invasion, and disease status. Furthermore, OC and HNSC patients with higher SK1 expression demonstrated shorter disease-free survival (p= 0.0037; p= 0.0087), whereas those with lower SPNS2 expression exhibited shorter overall survival (p= 0.051; p= 0.0012). High levels of ACER3 and low levels of S1PR1 were associated with shorter disease-free and overall survival in HNSC patients.

CONCLUSION

Several sphingolipid-related genes are deregulated in OC at the mRNA level and are associated with clinicopathological features and presented potencial for the prediction of poor prognosis in OC patients.

Recurrent fibrous solitary tumor of the parotid gland with satellite location: imaging, clinical and histological findings of rare entity

Fibrous Solitary Tumors are infrequent neoplasms originating from mesenchymal tissues, most commonly arising from the visceral pleura and frequently exhibiting a benign behavior. Extra-pleural localization is unusual and the site of origin of these tumors from the parenchyma of the parotid gland is considered extremely rare. We report the case of a 66-years old woman with non-painful slow-growing left latero-cervical mass, who underwent a gadolinium-enhanced Magnetic Resonance Imaging showing a mass originating from the deep lobe of the parotid gland extending into the retro-pharyngeal space. After a total parotidectomy with tumor excision, a diagnosis of histologically proven fibrous solitary tumor of the parotid gland was made. Two years later, CT scan showed post-operative recurrence and further satellite localization in the neck, distant from the initial mass. We performed a literature review of the published similar cases, in order to clinicopathological and imaging features of this rare entity.

Cytopathology of solitary fibrous tumor: a series of 34 cases

INTRODUCTION

Solitary fibrous tumor (SFT), a fibroblastic neoplasm characterized by a specific genetic alteration (NAB2-STAT6 fusion) and relatively specific immunohistochemical profile (STAT6/CD34 positivity), is seldom the subject of cytopathology data. We report our experience with scrape smears and fine-needle aspiration (FNA) biopsies of SFT in a large patient cohort.

MATERIALS AND METHODS

A search was made of our cytopathology and surgical pathology databases for cases diagnosed as solitary fibrous tumor (SFT). FNA biopsy smears, imprint smears, and cell blocks were performed and examined using standard technique.

RESULTS

Thirty-four cases from 30 patients (M:F = 1.1:1; age range: 24-86 years, x = 58 years) met inclusion criteria for this study. All patients had prior or subsequent tissue confirmation of SFT. Twenty-seven (79%) specimens were FNAs, and 7 (21%) were scrape smears. Most cases (29, 85%) represented primary tumors, 4 (12%) were metastatic deposits, and 1 (3.5%) was a locally recurrent neoplasm. Sites included: pleura/lung 9 (26%), head/neck 8 (24%), lower extremity 7 (21%), trunk 4 (12%), intra-abdominal 3 (9%), upper extremity 2 (7%), and mediastinum 1 (4%). Mean tumor size was 7.2 cm (range: 1.5-19 cm). Three (9%) cases were diagnosed specifically as SFT. Remaining diagnoses were spindle cell neoplasm/proliferation 14 (41%), nondiagnostic 5 (15%), specific type of sarcoma 3 (9%), malignant round cell tumor 2 (6%), sarcoma 2 (6%), malignant tumor 2 (6%) and single cases of melanoma, pleomorphic adenoma, and mesenchymal tumor. Immunohistochemical (IHC) testing was performed in 7 of 27 (26%) cell blocks.

CONCLUSION

SFT FNA cytopathology is morphologically ambiguous, overlapping with a broad array of other spindle cell proliferations. A specific diagnosis is only possible with added staining of STAT6 coupled with a set of other IHC markers.

[Sonography of the head and neck area - Part 1: Endosonography]

Sonography of the head and neck area plays a major role in both outpatient and inpatient ear, nose and throat medicine. Transcervical ultrasound is an important imaging method, especially in lymph node and tumor diagnostics. Its advantage is the ubiquitous availability and the excellent combinability with endoscopy and palpation. Despite decades of experience with sonography in the head and neck area, in contrast to the transcutaneous application, the transoral or endosonographic approach has so far not been widely used. Here it is often not due to the technical capabilities of the examiner, but rather to the unusual approach within the scope of the investigation. In this context, endosonography may be used primarily in tumor diagnostics in order to establish a complete sonographic examination from in- and outside.

Rare Diseases of the Nose, the Paranasal Sinuses, and the Anterior Skull Base

Due to their low incidence and thus resulting limited diagnostic criteria as well as therapeutic options, rare diseases of the nose, the paranasal sinuses, and the anterior skull base are a significant challenge. The value as of which a disease has to be considered as rare amounts to a maximum of 5 patients per 10 000 people. Within these diseases, however, there are extreme differences. Some rare or orphan diseases like for example the inverted papilloma belong to regularly diagnosed and treated diseases of larger departments of oto-rhino-laryngology whereas other rare diseases and malformations have only been described in less than 100 case reports worldwide. This fact emphasizes the necessity of bundling the available experience of diagnostics and therapy. The present article gives an overview about rare diseases of the nose, the paranasal sinuses, and the anterior skull base from the field of diseases/syndromes of the olfactory system, malformations of the nose and paranasal sinuses, ventilation and functional disorders as well as benign and malignant tumors. The classification and data on diagnostic and therapeutic options were established based on the current literature.

Histopathological findings and immunohistochemical expression of the stem cell markers CD44, ALDH1, Bmi-1, and Nanog in oral solitary fibrous tumors

OBJECTIVES

The aim of this study was to evaluate the histomorphologic presentation and the expression of stem cell-related markers in a series of oral solitary fibrous tumors (SFTs).

STUDY DESIGN

Histopathological variables and the expression of the standard stem cell markers CD34 and CD99, used for SFT diagnosis, as well as STAT6 were evaluated in 13 oral SFTs. The expression of the cancer stem cell markers CD44, ALDH1, Bmi-1, and Nanog and the tumor suppressor gene p16^Ink4a were also investigated.

RESULTS

The majority of oral SFTs were circumscribed and characterized by a proliferation of spindle cells arranged in a hyalinized stroma. Only 2 oral SFTs showed >4 mitoses/10 high-power fields. Hypercellularity as well as nuclear and cellular pleomorphism were classified as low and moderate in most of the oral SFTs. All oral SFTs were positive for CD34, STAT6, CD44, ALDH1, Bmi-1, and p16^Ink4a. CD99 and Nanog expression was observed in 11 and 10 oral SFT cases, respectively.

CONCLUSION

We suggest that STAT6 and ALDH1 have relevant diagnostic value. The expression of CD44, ALDH1, Bmi-1, and Nanog, which is observed in cancer stem cells, may confer advantages to oral SFT cells.

Factors for postoperative recurrence of orbital solitary fibrous tumor: an analysis of long-term clinical follow-up results from a Chinese tertiary hospital

BACKGROUND

This study analyzed the clinical features, imaging manifestations, histopathology, immunohistochemistry, and surgical approaches of the orbital solitary fibrous tumor (OSFT), as well as the factors for postoperative recurrence of such disease.

METHODS

The clinical data of 16 patients with OSFT treated in our center from 2003 to 2020 were analyzed retrospectively, and the clinical symptoms, treatment methods, and follow-up results were recorded.

RESULTS

Of the 16 patients, 8 were females (50.0 %) and 8 were males (50.0 %); the average age of treatment was 37 ± 7 years and the median follow-up time was 74 (8, 228) months. Sixteen patients with OSFT underwent a total of 29 operations, of which 12 were transorbital approach operations and 17 were transfronto-orbital approach operations. Ten patients (10/16, 62.5 %) had recurrence. The recurrence rate of transorbital approach operations was 83.3 % (10/12), and the recurrence rate of transfronto-orbital approach operations was 17.6 % (3/17). No patients had treatment-related complications.

CONCLUSIONS

The main pathological feature of OSFT is a benign tumor. OSFT has a tendency to grow toward the cranio-orbital junction. The postoperative recurrence rate of OSFT is relatively high, so complete tumor resection is very important for prognosis. Inappropriate surgical approaches can lead to incomplete removal of the tumor and cause recurrence. Choosing the correct operation approach according to the position of the OSFT in the orbit and complete removal of the dura mater and bone affected by the tumor is crucial for the prognosis. Nevertheless, regular long-term follow-up after complete resection is necessary.

Preoperative Embolization of a Solitary Fibrous Tumor Originating from External Auditory Meatus: A Case Report with Literature Review

Solitary fibrous tumors (SFTs) are mesenchymal, fibroblastic tumors with mostly favorable, but still unpredictable prognosis. Their rarity and occurrence at a variety of locations coupled with variable histological appearance make the diagnosis a challenge. This can be resolved by histological and immunohistochemical analysis on the histologic material eventually coupled with demonstration of NAB2-STAT6 gene fusion by next generation sequencing (NGS) analysis. Tumor removal with clear surgical margins is sufficient for complete cure in most cases. Percutaneous transcatheter embolization in well-vascularized lesions may minimize the risk of bleeding during subsequent removal. In this article we present a rare case of SFT arising from the external auditory canal and treated with preoperative endovascular arterial embolization. A literature review with focus on diagnostics and treatment of this entity in the head and neck region is following.

Endoscopic resection of solitary fibrous tumor of the ethmoid: Case report review of the literature

INTRODUCTION

Solitary fibrous tumour (SFT), as are benign neoplasms of fibroblastic cells. Nasosinusal localisation is exremely rare, difficult to diagnose and to manage.

CASE REPORT

We report a rare case of Solitary fibrous tumour in the nasal cavity in a 47-year-old- woman, with complete surgical resection.

DISCUSSION

SFTs are of mesenchymal origin, mainly from serous membranes. The head and neck region is affected with a percentage ranging from 5 to 27%. On the other hand, LTS unusually affects the nasal tract (NTS). Because of this rarity and its variable morphological appearance, it is difficult to distinguish TNS from other mesenchymal lesions.

CONCLUSION

Although there are no standard clinical guidelines, the preferred treatment for FLS is radical surgical resection.

Giant Cell-Rich Solitary Fibrous Tumor in the Nasopharynx: Case Report and Literature Review

Solitary fibrous tumors (SFTs) can occur in several locations outside the pleura, but rarely in the sinonasal tract, and particularly not in the nasopharynx. Herein, we describe an unusual case of giant cell-rich SFT (GCRSFT) occurring in the nasopharynx. A 64-year-old man experienced dizziness and headache for more than 10 years with no obvious cause. Computed tomography (CT) scan showed a 3.9 cm × 2 cm tumor on the posterior lateral wall of the left nasopharynx, and angiography revealed a hypervascular tumor fed by branches of the left carotid artery. Hence, preoperative embolization was performed, and then the tumor was endoscopically resected. The symptoms were relieved after the resection, and postoperative head CT and video laryngoscopy showed that the tumor was completely resected. We next characterized the specific pathological characteristics of the resected tumor. Histologically, the tumor was characterized by varying cellular proliferation of cytologically bland spindle cells within a collagenous stroma, with prominent interspersed branching vessels. Mitotic activity was low (2/50HPF), and there was no evidence of pleomorphism or tumor necrosis. Moreover, multinucleated giant cells with deep nuclear staining and distributed in pseudovascular spaces were found within the tumor. We ruled out the possibility that our case was giant cell fibroblastoma (GCF) by immunohistochemical analysis, showing that the tumor cells were positive for CD34, CD99, STAT6, and BCL-2, and that the Ki-67 labeling index was 3%, indicating that our case was SFT and not GCF. The patient's condition is generally good after a 14-month follow-up. This report serves to broaden the morphologic spectrum of GCRSFT and will help clinicians and pathologists better understand this entity to prevent misdiagnosis.

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.

Orbital solitary fibrous tumors: a multi-centered histopathological and immunohistochemical analysis with radiological description

BACKGROUND

Solitary fibrous tumors (SFT), formerly called hemangiopericytoma, are rare tumors derived from mesenchymal cells originally described in the pleura, but these tumors may affect extraserosal tissues including the lacrimal gland and orbit.

OBJECTIVE

Conduct a multi-centered clinical, radiological and histopathological analysis of 17 orbital SFT cases.

DESIGN

A retrospective case series.

SETTING

Three eye centers in two countries.

PATIENTS AND METHODS

The data collected from the charts of 17 adult patients presenting with tissue diagnosis of orbital hemangiopericytoma or SFT from January 2003 to December 2018 included demographics, clinical imaging and histopathological information including immunohistochemical (IHC) characteristics.

MAIN OUTCOME MEASURES

The demographic characteristics, clinical presentation, and histopathological patterns or variants of SFT were analyzed.

SAMPLE SIZE

17 adult patients.

RESULTS

Mean age was 45 years (range 23-80 years). Male to female ratio was 3:1. The right eye was affected in 12 (70.5%) patients. Commonest presentation was proptosis in 13/17 (76% of patients). Other symptoms were impaired motility (29%) and ptosis (11%). Lesions mostly affected the medial orbit (35%), then orbital apex in 11%. The histopathological classic pattern-less variant was the commonest. One case with aggressive behavior, multiple recurrences and atypical features was encountered. Immunohistochemical (IHC) markers used included CD34 expression in all cases, Bcl-2 expression in 10/11, CD99 in 9/9 and Vimentin in 4/4. STAT6 was used in 2 cases.

CONCLUSIONS

SFTs are rare tumors affecting the orbit in both genders equally in their mid-forties, but showed male predominance in our analysis with a predominant classic histopathological pattern. Tissue diagnosis is essential and requires IHC studies for confirmation.

LIMITATIONS

Sample size is relatively small owing to the rarity of this tumor in the orbit.

CONFLICT OF INTEREST

None.

Solitary Fibrous Tumor Arising in the Buccal Space

A 39-year-old Japanese woman presented to the Department of Oral and Maxillofacial Surgery, Okayama University Hospital, with the complaint of a slowly growing buccal mass. The mass was well defined, had rounded margins, and was free from skin and muscles. A color Doppler echographic examination indicated high flow velocity of the blood surrounding the mass. Contrast-enhanced images on CT and contrast-enhanced T1-weighted images on MRI displayed a homogeneous enhanced mass with a well-defined margin. A fine-needle aspiration biopsy and histological examination were performed. On immunohistochemistry, spindle cells were strongly positive for CD34, STAT6, and vimentin and negative for EMA, S100, and α-SMA. The tumor was removed with extracapsular dissection. The tumor was composed of bland spindle cells proliferating in a patternless arrangement with a collagenous background. Most of the tumor mass consisted of hypocellular areas including ectatic blood vessels. A prominent branching vascular pattern was observed. Immunohistochemistry demonstrated that the tumor cells were positive for CD34, STAT6, vimentin, and Bcl-2, and negative for α-SMA, S100, and EMA. Three mitotic cells were observed per 10 high-power fields, and the Ki-67 index was 5.7%. The morphological and immunohistochemical features were consistent with a diagnosis of solitary fibrous tumor.

Diagnosis of solitary fibrous tumor in the submandibular gland: Case report and literature review

Solitary fibrous tumors (SFTs) rarely occur in the head and neck area. Imaging findings are nonspecific, and immunohistochemical (IHC) analysis is necessary for a definitive diagnosis. We report the case of a patient with a mass in the submandibular region that was initially diagnosed as basal cell adenoma. After excision and IHC examinations, a SFT was diagnosed.

Solitary Fibrous Tumors in the Head and Neck: Comprehensive Review and Analysis

Solitary fibrous tumors (SFT) arising in the head and neck region are uncommon yet well-recognized entities. Their biologic behavior and management still need to be elucidated. Systematically reviewing all published cases of SFT involving the head and neck region since 1991, a pooled meta-analysis was conducted to evaluate various demographic and tumor characteristics. 587 SFT in the head and neck have been reported; 343 met pooled analysis inclusion criteria. 61% of cases presented as a new mass; 89% were painless. Median onset of symptoms prior to evaluation was 8 months. Pre-operative local invasion and malignant histological features (hemorrhage, necrosis, mitoses > 4/10 hpf) were not statistically associated with decreased recurrence-free survival. Positive surgical margins was the only factor associated with shorter recurrence-free survival (p < 0.001). The evidence presented herein reveals novel associations between clinical presentation and tumor characteristics that provide otolaryngologists with new insight into SFT tumor behavior, thus prompting further investigations.

Solitary fibrous tumour of the parotid gland: a case report and a 15-year literature review

Solitary fibrous tumour (SFT) is uncommonly found in the salivary glands and is a rare group of spindle-cell tumours. A review of literature revealed only 40 reported cases of SFT of major salivary glands over a 15-year period from 2004 to 2018. SFTs of the salivary glands are usually benign, although rarely, can be aggressive and may sometimes recur after initial resection. Histology and Immunohistochemistry are the most important criteria to distinguish SFT from other head and neck tumours. SFTs strongly stain for CD34 and hence is the most frequently used stain for diagnosis. All reported SFT cases with available information on immunohistochemical stains were positive for CD34. Recently, immunohistochemistry for STAT6 has been introduced as a surrogate diagnostic marker for SFT that is highly sensitive and specific. We report a case of a 51-year-old Chinese gentleman who presents with a 3-month history of a left parotid tumour that required a subtotal parotidectomy for complete excision. It was diagnosed as SFT based on histology and immunohistochemical features. He was followed-up for 3 months post-operatively with no clinical evidence of recurrence. This case proposes that, although rare, SFT should be considered in the differential diagnosis of soft-tissue tumors in the major salivary glands. An awareness of this rare entity will help clinicians and pathologists better manage similar patients in the future.

Thyroid Gland Solitary Fibrous Tumor: Report of 3 Cases and a Comprehensive Review of the Literature

Solitary fibrous tumors of the thyroid gland are exceptionally rare. In order to further characterize the clinical and pathologic features of solitary fibrous tumor arising at this anatomic site, three cases of thyroid gland solitary fibrous tumor were analyzed in conjunction with 35 cases compiled from the English literature. Thyroid gland solitary fibrous tumors showed an equal sex distribution with a mean age at presentation of 54.4 years (range, 28-88 years). The patients typically presented with an asymptomatic, slow growing neck mass. 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. Two previous reported tumors were considered to be histologically malignant on the basis of increased mitotic activity, profound pleomorphism and tumor necrosis. Immunohistochemically, the tumor cells are variably positive with CD34, bcl-2, and CD99. STAT6 immunohistochemistry, performed on the current cases, demonstrated a strong, diffuse nuclear expression in all tumors. Among 26 patients with available follow up data (mean 47.3 months), one developed local recurrence and distant metastasis. Solitary fibrous tumors occurring in the thyroid gland are uncommon, but can be reliably diagnosed based on the presence of characteristic morphologic features as well as immunohistochemical expression of STAT6 and CD34. The majority of thyroid gland solitary fibrous tumors have exhibited an indolent clinical course, however experience is limited. The rare potential for aggressive clinical behavior requires clinical surveillance.

Ear and Temporal Bone Pathology: Neural, Sclerosing and Myofibroblastic Lesions

Neural, sclerosing, and myofibroblastic lesions of the ear and temporal bone present diagnostic challenges for both clinicians and pathologists due to significant overlap in their clinical presentations, histologic appearances, and immunohistochemical profiles. While some of these lesions, such as schwannomas, are relatively common, others are rendered even more difficult because they are encountered very rarely in routine surgical pathology practice. This review is intended to provide an update on the pathology of some of the most commonly encountered primary diagnostic entities for the ear and temporal bone, and includes the following neural lesions: schwannoma, meningioma, and encephalocele/meningocele. Sclerosing lesions that will be discussed include spindle cell and sclerosing rhabdomyosarcoma, sclerosing epithelioid fibrosarcoma, and sclerosing paraganglioma. Finally, myofibroblastic lesions that will be reviewed are nodular fasciitis, IgG4-related disease, and solitary fibrous tumor. For each of these lesions, the differential diagnosis and useful ancillary tests will be discussed in the context of a broad range of additional primary and secondary lesions.

Orbital solitary fibrous tumor: a clinicopathologic study from a Chinese tertiary hospital with a literature review

Purpose

To report the clinical features, imaging manifestations, histopathology, and immunohistochemical features of several cases of orbital solitary fibrous tumors (SFTs) in a Chinese tertiary hospital, and to undertake a literature review of this rare disease.

Methods

A non-comparative retrospective review of clinical presentations, imaging manifestations, histopathology, and immunohistochemical features as well as the management and disease outcomes of patients with orbital SFT was conducted along with a review of orbital SFT cases in the literature.

Results

This study includes two male and two female patients, with an average age of 53 years. Common presentations among these patients included a palpable subcutaneous mass, swelling of the eyelid, proptosis, diplopia, and vision disturbance. Three patients (cases 2–4) underwent imaging scans. All patients had complete surgical excisions and the tissue was subjected to pathological analysis. One patient (Case 4) experienced a recurrence with malignant transformation and received a re-excision surgery and postoperative radiotherapy. All patients remain alive and well after a minimum follow-up of 12 months (range 12–34 months).

Conclusion

Despite its rare occurrence, we suggest that the possibility of orbital SFTs needs to be considered when a painless, slowly growing orbital mass is identified. Typical characteristic magnetic resonance imaging features of orbital SFTs are iso- or hypointense signals on T1 and T2-weighted images, with marked enhancement. A positive cluster of differentiation 34 (CD34) staining is an important diagnostic clue favoring SFT. Some orbital SFTs are infiltrating, aggressive, or recur with malignant transformation. Therefore, regular long-term follow-up after complete excision is mandatory.

Sinonasal Tract Solitary Fibrous Tumor: A Clinicopathologic Study of Six Cases with a Comprehensive Review of the Literature

Solitary fibrous tumors (SFTs) are well recognized in the head and neck region, but rarely arise in the sinonasal tract (SNT). Six primary SNT SFTs were identified in the files of Southern California Permanente Medical Group between 2006 and 2017. The patients included five males and one female ranging in age from 33 to 72 years (mean 52 years), most of whom presented clinically with nasal obstruction. Three tumors involved the nasal cavity alone, one involved the paranasal sinuses, and two involved both the nasal cavity and paranasal sinuses. Histologically, the tumors were characterized by a variably cellular proliferation of cytologically bland spindle cells within a collagenous stroma with prominent interspersed branching vessels. Mitotic activity was low (range 0-2 per 10 high power fields) and there was no evidence of pleomorphism or tumor necrosis. Surface ulceration was noted. By immunohistochemistry, the lesional cells were positive for CD34, STAT6 and bcl-2. Clinical follow up information was available for all patients (range 32-102 months; mean 72 months). There were no recurrences or metastases and all were alive with no evidence of disease at last follow-up. SFTs rarely affect the SNT, but should be considered in the differential diagnosis of SNT mesenchymal lesions. Immunohistochemical expression of STAT6 can aid in diagnosis and separation of SFT from other spindle cell lesions occurring at this anatomic site. In combination with cases reported in the literature, primary SNT SFT behave in an indolent manner with conservative treatment.

Solitary Fibrous Tumors of the Head and Neck: A Multi-Institutional Clinicopathologic Study

Solitary fibrous tumors (SFTs) of the head and neck are uncommon. Lesions previously diagnosed in the head and neck as hemangiopericytomas (HPCs), giant cell angiofibromas (GCAs), and orbital fibrous histiocytomas (OFHs) are now recognized as within the expanded spectrum of SFTs. To better understand the clinicopathologic profile of head and neck SFTs, we performed a multi-institutional study of 88 examples. There was no sex predilection (F:M ratio 1.2), and the median patient age was 52 years (range: 15 to above 89 y). The sinonasal tract and orbit were the most common sites involved (30% and 25%), followed by the oral cavity and salivary glands (15% and 14%). Original diagnoses included HPC (25%), SFT (67%), and OFH (6%), with 1 SFT and 1 OFH noted as showing GCA-like morphology. On review, the predominant histologic pattern was classic SFT-like in 53% and cellular (former HPC-like) in 47%; lipomatous differentiation (8%) and GCA-like pattern (7%) were less prevalent. Subsets demonstrated nuclear atypia (23%), epithelioid morphology (15%), or coagulative necrosis (6%). Infiltrative growth (49%) and osseous invasion (82%) were prevalent among evaluable cases. Of the 48 SFTs with follow-up (median: 43 mo), 19 showed recurrence (40%). Of these, 4 patients were alive with disease and 4 dead of disease. Size and mitotic rate were negative prognosticators using a joint prognostic proportional hazards regression model. Three patients experienced metastasis, to lungs, parotid, bone, and skull base, including one case showing overtly sarcomatous "dedifferentiation." As a group, SFTs present in a wide anatomic and morphologic spectrum in the head and neck. Only rare examples metastasize or cause death from disease. However, the fairly high local recurrence rate underscores their aggressive potential and highlights the importance of prospective recognition.

Solitary fibrous tumour of the tongue: a series of four cases

Background:

Solitary fibrous tumour is a soft tissue tumour of mesenchymal origin. It was first described in the pleura and has since been reported in many anatomical locations. Thirteen cases in the tongue have hitherto been reported. A positive CD34 result has traditionally been used to confirm the diagnosis, although this is often non-specific to solitary fibrous tumour. To date, nuclear STAT6 expression has not been reported in solitary fibrous tumour of the tongue.

Method:

This paper presents a further four cases of solitary fibrous tumour of the tongue, the largest series to date. Clinical, histopathological and immunohistochemical findings are detailed, including nuclear STAT6 expression.

Results:

All four cases were positive for CD34; two cases showed nuclear expression of STAT6. The tumours were excised completely and there have been no recurrences in at least one year.

Conclusion:

Solitary fibrous tumour should be considered as a differential diagnosis for tongue swellings, with the potential to recur.

A Rare Case of a Recurrent Giant Solitary Fibrous Tumor of the Ciliary Body of the Orbit

Solitary fibrous tumors (SFTs) are uncommon spindle-cell tumors of mesenchymal origin initially described in the pleura and subsequently in other extra-pleural sites. These tumors are categorized as tumors of 'intermediate malignancy' under the World Health Organization classification of soft tissue tumors. SFT was virtually non-existent or misdiagnosed until its characteristic features, particularly the strong and diffuse immuno-reactivity to CD 34 were described. Extra-pleural manifestations of SFT, particularly in the head and neck region are rare. Although a number of isolated case reports of orbital SFTs have been described ever since its initial description in 1994, cases of recurrent SFTs have been very few. Recurrences of these tumors following surgery are considered unusual and metastasis exceptional. We describe clinical presentation and the management challenges of recurrent giant orbital SFT in a 15-year old girl along with a brief review of literature.

Update on Select Benign Mesenchymal and Meningothelial Sinonasal Tract Lesions

Several benign and malignant mesenchymal and meningothelial lesions may preferentially affect or extend into the sinonasal tract. Glomangiopericytoma (GPC, formerly sinonasal-type hemangiopericytoma) is a specific tumor with a predilection to the sinonasal tract. Sinonasal tract polyps with stromal atypia (antrochoanal polyp) demonstrate unique histologic findings in the sinonasal tract. Juvenile nasopharyngeal angiofibroma (JNA) arises from specialized tissue in this location. Meningioma may develop as direct extension from its intracranial counterpart or as an ectopic tumor. Selected benign mesenchymal tumors may arise in the sinonasal tract and pose a unique differential diagnostic consideration, such as solitary fibrous tumor and GPC or lobular capillary hemangioma and JNA. Although benign and malignant vascular, fibrous, fatty, skeletal muscle, and nerve sheath tumors may occur in this location, this paper focuses on a highly select group of rare benign sinonasal tract tumors with their clinicopathological and molecular findings, and differential diagnosis.