Solitary fibrous tumour--everywhere, and a diagnosis in vogue

Solitary fibrous tumor of the ischioanal fossa-a multidisciplinary approach to management with radiologic-pathologic correlation

Solitary fibrous tumors are primary mesenchymal tumors, which may occur in any part of the body. Overall, these tumors are considered to have intermediate malignant potential with 5- and 10-year metastasis-free and overall disease-specific survival rates of 74% and 55%, and 89% and 73%, respectively (Demicco et al, 2012). Herein we present an unusual case of solitary fibrous tumors involving the ischioanal fossa in a 19-year-old woman with radiologic-pathologic correlation. This case was complicated by extensive tumor vascularity and was thus managed with preoperative embolization followed by en bloc surgical resection.

Myxoid Solitary Fibrous Tumor on the Scalp

Myxoid solitary fibrous tumor (SFT) is very rare soft tissue neoplasm. It is microscopically composed of spindle cells which is individually separated by delicate band of collagen fibers. And this tumor cells are immunohisto-chemistrically highlighted by CD34. Myxoid SFT has indolent clinical course and a good prognosis, so it is important to make a diagnosis because of its morphological similarities to myxoid spindle cell neoplasms that have different prognoses and treatment. We report the case of a 20-year-old female with a myxoid SFT found in the left temporo-parietal scalp. This case report appears to be the first reported scalp occurrence of this rare tumor.

Solitary fibrous tumour of the mesentery: a case report

We present the case of a male with an asymptomatic abdominal mass, where imaging-guided biopsy confirmed the lesion as a solitary fibrous tumour arising from the mesentery. This is a notably rare location for solitary fibrous tumours with only a few reported cases in the literature.

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.

Soft Tissue Solitary Fibrous Tumor: Combined Surgery and Radiation Therapy Results in Excellent Local Control

PURPOSE

To report survival outcomes and local control in patients with solitary fibrous tumors (SFT) treated using surgery and radiation therapy (RT).

METHODS

We reviewed the medical records of 31 consecutive patients definitively treated for SFT with surgery and RT between 1982 and 2012. The median age was 51 years (range, 23 to 88 y) and tumors were evenly distributed between the head and neck (n=9, 29%), trunk (n=10, 32%), and lower extremities (n=9, 29%). The majority of tumors were large (>5 cm) (n=23, 72%). Specimens had a median of 2 mitoses/10 HPF (range, 0 to 8). Nearly half the cases were treated with postoperative RT (n=14, 45%; median dose, 58 Gy) and the other 17 patients (55%) received preoperative RT (median dose, 50 Gy).

RESULTS

Median follow-up time was 59 months (range, 18 to 349 mo). The 5-year rates of local control, overall survival, and distant metastatic-free survival were 100%, 95%, and 92%, respectively. There were no local or nodal relapses and the 10-year complication rate was 6% (n=2).

CONCLUSIONS

Treatment of soft tissue SFT using combined surgery and RT results in excellent local control.

Scrotum solitary fibrous tumor: A case report and review of literature

BACKGROUND

A solitary fibrous tumor (SFT) is a rare clinical tumor, often manifesting as solitary nodules. It is a rare condition that occurs in the scrotum. Currently, no study has reported this condition.

CASE SUMMARY

We reported a case of an SFT in a 77-year-old man, and discuss its diagnosis, differential diagnosis, and treatment. Clinical and histopathological features, as well as the EnVision 2-step method, were used to diagnosis the SFT. The results of imaging tests and surgery indicated that the SFT was located in the right scrotum with 2 connected tumor nodules and a clear perimeter. The larger one was 11.0 cm × 9.3 cm × 8.1 cm, and the smaller one was 3.1 cm × 2.0 cm × 2.0 cm. Pathological results indicated that in both tumor nodules, tumor cells were spindle-shaped with unclear cell boundaries. The nucleus was vacuolated with mild to moderate atypia. In the larger tumor nodule, there were many thin-walled blood vessels with vasodilation or branching. In the smaller tumor nodule, rich blood vessels were found, mostly with fibrous degeneration of the thick walls of blood vessels, and more collagen-like tissue in the interstitial layers. Immunohistochemical results demonstrated diffuse, strongly positive expression of CD34, CD99, Vim, and Bcl-2 markers. The expression of the new fusion gene, NAB2-STAT6, as an alternative tool specifically confirmed the diagnosis of SFT. This patient underwent lump resection without further treatment. The patient is alive after 18-month follow-up.

CONCLUSION

This case was diagnosed as a SFT according to its histopathological features, immunophenotype. The patient is still alive at 18 months follow-up after the lump resection.

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 tumor occurring in the parotid gland: a case report

Background

Solitary fibrous tumor is an uncommon spindle cell neoplasm of unknown origin. It has been reported in many anatomic sites, with a rare occurrence in the head and neck region. Solitary fibrous tumors of the parotid gland are exceptional; their clinical and radiologic features are non specific, often mimicking more common salivary gland tumors. Pathologic examination and immunohistochemistry are required to make the correct diagnosis. The prognosis is favorable, with most tumors being benign, and complete surgical resection is the treatment of choice.

Case presentation

We report the case of a 42-year-old man who presented with a painless mass involving the parotid gland. A parotidectomy was performed, and follow up was unremarkable. Gross examination showed a well circumscribed, firm tumor measuring 3,4 cm. Histologically, the tumor was composed of a spindle cell proliferation of variable cellularity, with staghorn vessels. A panel of immunohistochemical stains was performed, and confirmed the diagnosis of parotid gland solitary fibrous tumor.

Conclusion

In this report we aim to increase awareness of this rare entity among clinicians and pathologists, and to emphasize the role of immunohistochemistry in confirming the diagnosis.

Solitary Fibrous Tumor of the Pleura

BACKGROUND

The solitary fibrous tumor of the pleura (SFTP) is a rare primary tumor arising from mesenchymal cells in the areolar tissue subjacent to the mesothelial-lined pleura. Only about 800 cases have been reported in the medical literature. The tumor appears to be unrelated to malignant pleural mesothelioma, the most common primary tumor of the pleura.

METHODS

In just over half of these cases, the neoplasm presents as an asymptomatic mass, is often quite large, and is benign in 78% to 88% of patients. The initial evaluation and diagnosis, tumor classification, surgical treatment, results of therapy, and long-term prognosis are reviewed, based on a selective review of the literature from MEDLINE beginning 1980.

RESULTS

Complete en bloc surgical resection is the preferred treatment of benign and malignant varieties of the tumor. The pedunculated tumors attached to the visceral pleura can be effectively treated with a wedge resection of lung. Sessile tumors arising on the lung require a larger lung resection. Sessile tumors on the chest wall require wide local excision, often with chest wall resection because of their propensity for local recurrence. Adjuvant therapy remains controversial in SFTP.

CONCLUSIONS

Benign SFTP has a high cure rate and an 8% local recurrence rate that is usually amenable to curative re-excision. Malignant SFTP, especially the more common sessile type, has a 63% recurrence rate even with complete resection. The majority of patients with recurrent disease die of the tumor within 2 years. Nevertheless, the overall long-term cure rate for all patients is 88% to 92%.

Solitary fibrous 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.

VATS and open chest surgery in diagnosis and treatment of benign pleural diseases

A negative pressure normally exists between the visceral and parietal pleurae in the lungs, which can act as vacuum for fluid, air and small particles from different parts of the body, allowing them to move into the pleural space and be retained in it, thus resulting to different manifestations of pleural disorders. A pleural effusion is the result of fluid collection between the parietal and visceral pleural surfaces. The most common cause in developed countries is congestive heart failure, followed by pneumonia and malignancy. It is highly important that a systematic approach is undertaken during the investigation of pleural effusions. Treatment should be based on the nature of the effusion and underlying condition, while undiagnosed patients should remain under surveillance. Pleural infection is a serious clinical condition which affects approximately 65,000 patients every year in the UK and can result in mortality in rates as high as 20%. The selection of treatment as well as timing of intervention remains a debatable issue among pulmonologists and thoracic surgeons. Surgical intervention aims to control sepsis, by facilitating evacuation of necrotic material from the pleural space, and obliterate the empyema cavity, by allowing the trapped lung to re-expand via peeling of the organised cortex from its visceral pleura. Thoracoscopic surgery offers the advantages of visual assessment of the pleural space and direct tissue sampling and it can be useful for the diagnosis of unknown pleural effusions and in the management of complicated collections. Open thoracotomy remains the gold standard, however with the advancement of thoracoscopic instruments and techniques, minimally invasive approaches provide comparable outcomes and have been taking over the management of benign pleural diseases.

Extrapleural solitary fibrous tumor in thymic area: A case report

RATIONALE

Solitary fibrous tumor (SFT) is a rare benign soft tissue mesenchymal neoplasm. There have been a few reports of extrapleural SFTs although it can occur anywhere in the body.

PATIENT CONCERNS

A 30-year-old male presented with an anterior neck mass since one month.

DIAGNOSES

Based on physical and radiologic examination, preliminary differential diagnosis was thymic neoplasm or intrathoracic goiter.

INTERVENTIONS

We performed surgical excision of the neck mass.

OUTCOMES

The histopathological examination revealed an extrapleural SFT LESSONS:: We present a case of extrapleural SFT in the thymus which was misdiagnosed as thymoma based on radiologic findings.

Malignant solitary fibrous tumor in retroperitoneum: A case report and literature review

RATIONALE

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor occurs in various sites. Malignant SFT in retroperitoneum is extremely rare.

PATIENT CONCERNS

We report a case of malignant retroperitoneal SFT in a 59-year-old man presented with right flank pain for 1 month.

DIAGNOSES, INTERVENTIONS AND OUTCOMES

A laparotomy and resection of the tumor were performed, the histopathologic and immunohistochemical findings were consistent with malignant retroperitoneal SFT. No adjuvant treatment was performed, and the patient had no signs of recurrence or metastasis at the 12 months follow-up.

LESSONS

Complete surgical excision is the basic treatment principle for malignant retroperitoneal SFT. The histologic features and the Ki-67 label index are helpful for the diagnosis of malignant SFT.

Solitary Fibrous Tumors: 2016 Imaging Update

Optimal management of solitary fibrous tumor requires a multidisciplinary approach with proper histopathological mapping and use of various imaging modalities for exact delineation of primary tumor and metastatic disease if present. In this article, the authors present a comprehensive review of the spectrum of imaging findings of solitary fibrous tumors involving various organ systems and discuss the role of molecular targeted therapies in the management of metastatic disease.

Solitary fibrous tumor of the greater omentum, mimicking gastrointestinal stromal tumor of the small intestine: a case report

Solitary fibrous tumor (SFT) is one of the mesenchymal tumors, which rarely arises in the abdominal space. We report a very rare case of abdominal SFT, mimicking another mesenchymal tumor. A 52-year-old Japanese man was referred to our hospital for further evaluation and treatment of gallbladder polyp. Contrast-enhanced computed tomography (CT) showed an enhanced nodule within the gallbladder, and incidentally, also showed a well-circumscribed mass adjacent to the small intestine. The mass was depicted as slightly high density in plain CT, and with contrast-enhancement, the mass was partially stained in early phase and the stained area spread heterogeneously in delayed phase. Magnetic resonance imaging showed that the abdominal mass was depicted as slightly high intensity on T2-weighted imaging and low intensity on T1-weighted imaging. With double-balloon endoscopy and capsule endoscopy, we did not find any tumor inside the small intestine. These visual findings lead us to diagnose it as gastrointestinal stromal tumor of the small intestine with extraluminal growth. We planned to resect both the gallbladder polyp and the intraperitoneal tumor at the same time for pathologic diagnosis and treatment. When the operation was performed, we found a milk-white lobulated tumor on the greater omentum and the tumor was entirely resected. Microscopically, the gallbladder polyp was diagnosed as tubular adenoma, and the omental tumor was diagnosed as SFT. It is important to bear in mind that omental SFTs sometimes mimic other mesenchymal tumors and should be included in the differential diagnosis of abdominal tumor not revealed by endoscopy.

The Value of MRI and Clinical Features in Differentiating Between Cellular and Fibrous Solitary Fibrous Tumors

OBJECTIVE

The purpose of this study is to evaluate the usefulness of MRI in differentiating between fibrous and cellular solitary fibrous tumors (SFTs).

MATERIALS AND METHODS

This retrospective study included 17 patients with histopathologically confirmed SFTs, including 10 patients with fibrous SFTs and seven patients with cellular SFTs. We evaluated the differences between fibrous and cellular SFTs with regard to clinical data and MRI findings, such as tumor margin definition, signal intensity, heterogeneity on T1- and T2-weighted images, presence of capsules, intratumoral cystic changes, flow signal void, perilesional edema, enhancement pattern on dynamic contrast-enhanced MRI (DCE-MRI), and mean apparent diffusion coefficient (ADC) values.

RESULTS

Statistically significant differences in fibrous and cellular SFTs were noted with respect to signal intensity on T2-weighted images (p = 0.044, by Fisher exact test) and enhancement patterns on DCE-MRI (p = 0.005, by Fisher exact test). Specifically, on T2-weighted images, five of the fibrous SFTs had high signal intensity, and the other five had signal isointensity, whereas all seven cellular SFTs had high signal intensity. On DCE-MRI, fibrous SFTs tended to show a gradual increase in enhancement, whereas cellular SFTs showed a rapid initial enhancement pattern. The mean (± SD) ADC value for cellular SFTs was 1.39 ± 0.35 × 10^-3 mm²/s, whereas that for fibrous SFTs was 1.37 ± 0.48 × 10^-3 mm²/s, with no statistically significant difference noted between the two (p = 0.755, by Fisher exact test).

CONCLUSION

Fibrous SFTs have nonspecific findings with regard to signal intensity on T2-weighted MR images and enhancement patterns on DCE-MRI, whereas cellular SFTs show high signal intensity on T2-weighted images and rapid initial enhancement on DCE-MRI.

Recurrent solitary fibrous tumor of lumbar spine with vertebral body involvement: imaging features and differential diagnosis with report of a case

Solitary fibrous tumors (SFTs) of the spine are exceedingly rare tumors of mesenchymal origin. Most spinal SFTs arise from the thoracic spine, followed by cervical spine, and last lumbar spine with only 6 cases reported in literature. SFTs represent a wide range of neoplasms, ranging from benign to malignant. These tumors can develop a late recurrence, even after a decade or more of initial presentation, requiring long-term follow-up. We present a case of recurrent SFT of the lumbar spine with vertebral body involvement, presenting more than a decade after initial resection. It was initially misdiagnosed as a paraganglioma. To the best of our knowledge, there have been only 3 previous cases reporting SFT with vertebral body involvement.

Solitary fibrous tumour presenting with a single bone metastasis: report of six cases and literature review

Background

Solitary fibrous tumour (SFT) is a rare soft tissue sarcoma with a low metastatic potential. A higher metastatic rate is observed in the high-grade/dedifferentiated variant. The most common expected site of distant spread are the lungs and the liver. Bone involvement is generally viewed as a late stage of disease spread. We report on a retrospective series of SFT patients relapsing with a single distant bone recurrence as first metastatic event, without evidence of other organ involvement.

Case presentation

All patients affected by a single distant bone metastasis from SFT as first distant event, without any evidence of other site of metastasis, observed at our Institution, were considered. Bone involvement from SFT was pathologically assessed in all cases and confirmed by expert pathologists. A total of six patients were retrospectively identified. Primary tumour arose from the meninges in four patients, from soft tissues in two. Bone metastases were located to the vertebrae, the hip, the acetabulum and the rib. In all cases, bone relapse was the first event, with one patient presenting a local relapse. Median time from the primary tumour and the evidence of bone relapse was 40 months (range 0–58). In 2/6 patients bone metastasis was treated with radiotherapy (RT), in 2/6 with surgery, in 2/6 with surgery plus RT. At a median follow-up of 55 months (range 23–88), 5/6 patients are alive (2/5 without disease, 3/5 with multicentric metastatic disease) and one is dead of disease. 2/6 patients did not relapse after the treatment of the bone metastasis.

Conclusions

This small series in a relatively rare histology suggests that isolated, possibly late, bone metastases are a plausible scenario, in particular in meningeal SFT. Notably, new bone lesions in a patient with a history of SFT should be always investigated. Exclusive local treatments may be an option, though collection of such series would be needed to define the best treatment strategy.

Malignant Solitary Fibrous Tumor of the Scalp

Solitary fibrous tumors are an uncommon slow growing benign neoplasm originally described as a pleural neoplasm but can also be found in the lung, mediastinum, peritoneum, or any other sites including the head and neck. Malignant solitary fibrous tumors (MSFT) are extremely rare and only few cases have been published in the literature. There have been 19 cases reported of MSFT in the head and neck, but there are no reports of MSFT located within the scalp in the English language literature. We present a case of MSFT arising in the scalp and describe our experience with the clinical presentation, surgical management, and outcome in this pathological condition.

The Current Status of Solitary Fibrous Tumor: Diagnostic Features, Variants, and Genetics

Solitary fibrous tumor (SFT) is a fibroblastic mesenchymal tumor originally described in the pleura but now shown at almost every anatomic site. Histopathologically, SFT is characteristically a circumscribed neoplasm composed of variably cellular and patternless distributions of bland spindle and ovoid cells within prominent collagenous stroma and shows diffuse expression of CD34, but it has a broad spectrum of both morphology and of biologic behavior. Many different names (particularly hemangiopericytoma) were previously used in the course of our understanding of this neoplasm but are now subsumed under the term "SFT," and the putative cell of origin was debated. However, it is now recognized that SFT is a translocation-associated neoplasm, consistently associated with NAB2-STAT6 gene fusions arising from recurrent intrachromosomal rearrangements on chromosome 12q, and this translocation is a likely major contributor to its pathogenesis. While most SFT with classical morphologic features behave in an indolent manner and those with overtly malignant histologic features tend to be aggressive neoplasms that behave as high-grade sarcomas, the behavior of SFT is unpredictable, and it is important to be aware of the propensity for aggressive behavior in a minority of histologically classical SFT and to ensure adequate clinical follow-up. Surgical excision remains the treatment gold standard; while radiotherapy and conventional chemotherapeutic agents have only shown limited efficacy, further understanding of the molecular events underlying tumorigenesis may allow the development of novel targeted treatments. We review SFT, discussing the morphologic spectrum and variants, including malignant and dedifferentiated subtypes, clinicopathological aspects, recent molecular genetic findings, and the differential diagnosis.

Solitary fibrous tumor of the sellar region treated with adjuvant radiation therapy

The solitary fibrous tumor of central nervous system is rare. Herein, a case of solitary fibrous tumor arising from sellar region is described. A 60-year-old man underwent subtotal excision of the tumor because of extensive infiltration of optical and vascular structures. In view of the presence of residual tumor, he was treated with adjuvant radiation therapy. After a follow-up period of 1 year, there was no progression of the lesion evident on magnetic resonance imaging of the brain. Solitary fibrous tumor should be considered as one of the differential diagnosis of a mass lesion arising in sellar region. Immunohistochemistry with CD34 is valuable for discerning the diagnosis. Complete surgery should be the goal of treatment and adjuvant radiation therapy may be considered for residual or recurrent disease.

Solitary fibrous tumour of the supraglottic larynx

Solitary fibrous tumour (SFT) is a rare, benign, mesenchymal neoplasm that usually arises in the pleura, but rarely involves other sites outside the serosal space (mediastinum, lung, liver, thyroid gland); larynx involvement is very rare with only sporadic cases reported in the literature. We report a case of SFT in a 41-year-old woman with supraglottic laryngeal invovlement; symptoms included dysphonia and mild odynophagia lasting 2 years, and fibre-optic laryngeal evaluation showed a sub-mucosal mass involving the left supraglottis and medial wall of the pyriform sinus. MRI represents the gold standard tool for differential diagnosis (with schwannoma, paraganglioma and haemangioma) and correct staging, while immunohistochemical and cytomorphologic analysis (bcl-2 and CD34 positivity in 90% of cases) is needed for definitive diagnosis. Surgery is the main treatment (endoscopic and open conservative technique), and its goal is a balance between safe oncological resection and good preservation of laryngeal functions; in this particular case an open laryngeal approach was scheduled due to the size of the tumour. Prognosis is good and in only a few cases (especially in pleural SFT) does the biological behaviour take a malignant course.

Transsphincteric tumor resection in case of a pararectal solitary fibrous tumor

Transsphincteric resection of rectal tumors was first described about 120 years ago. Nowadays, this approach faded into obscurity due to standardized guidelines and practice in surgical oncology including lymphadenectomy, mesorectal excision and radical dissection of veins. However, transsphincteric resection seems reasonable in some cases, especially if an abdominal approach can be avoided. In the following, we will present and describe the technique of the transsphincteric approach with its variations in rectal surgery in the case of a rare pararectal tumor.

Solitary Fibrous Tumor of the Pleura: A Rare Cause of Pleural Mass

BACKGROUND

A solitary fibrous tumor of the pleura is a rare but usually benign mesenchymal tumor arising from the pleura. Patients are often asymptomatic, resulting in the majority of tumors being detected incidentally on chest imaging. We present a case of a large solitary pleural tumor and review the typical radiographic and pathologic findings associated with this finding.

CASE REPORT

A 63-year-old white man with chronic obstructive pulmonary disease (COPD) was found to have a large pleural mass on chest radiography during a pre-operative assessment. The tumor was biopsied and findings were consistent with solitary fibrous tumor of the pleura.

CONCLUSIONS

SFTPs are generally considered benign tumors although there is a risk of malignant transformation and recurrence. Imaging studies play an important role in identifying the tumor and planes of resection, and histologic diagnosis is critical in differentiating SFTP from other type of pleural masses. Surgical resection is main therapy of choice.

Clinicopathologic and immunohistochemical features of five new cases of solitary fibrous tumor of the oral cavity

OBJECTIVE

To describe the clinicopathologic and immunohistochemical features of five cases of oral solitary fibrous tumor.

STUDY DESIGN

Clinical data were collected from charts of two oral pathology laboratories of Latin America. All cases were evaluated by conventional hematoxylin and eosin staining and an extended immunohistochemical panel comprising vimentin, CD34, CD99, bcl-2, HHF-35, smooth muscle actin, calponin, S-100 protein, h-caldesmon, and Ki-67.

RESULTS

The study included 1 male (20%) and 4 female (80%) patients, with a median age of 43 years. The most common affected site was the buccal mucosa (40%). Tumors were characterized by proliferation of spindled and ovoid cells in a variably vascular and collagenized stroma. All tumors were positive for vimentin, CD34, bcl-2, and CD99. Recurrence was not observed after complete surgical enucleation.

CONCLUSIONS

Oral solitary fibrous tumors usually appear as well-delimited submucous nodules with a firm-rubbery consistency and covered by intact mucosa. Immunoreactivity for CD34, bcl-2, and CD-99 is helpful to confirm the diagnosis.

A GRIA2 and PAX8-positive renal solitary fibrous tumor with NAB2-STAT6 gene fusion

Solitary fibrous tumor (SFT) is a rare neoplasm composed of mesenchymal-derived spindle cells. Although SFT occurs anywhere in the body, they most frequently affects the thoracic region. Here, we reported an extremely rare case of an extrathoracic SFT occurring primarily in the kidney. To our knowledge, little information has been described on the immunohistochemistry (IHC) and genetics of renal SFT.

A 41-year old Japanese female came to our hospital for further examination of a left kidney mass detected incidentally with ultrasound. Extensive investigation of the tumor, including physical, laboratory, and image examinations led to a clinical diagnosis of renal cancer (cT1aN0M0), which were in most parts imbedded in the lower polar parenchyma. The patient underwent laparoscopic radical nephrectomy. The mass was diagnosed pathologically as SFT originating from the kidney, but not as renal carcinoma. Microscopically, the tumor was composed of spindle-shape cells distributed variably in dense collagenous stroma and had a focal hemangiopericytomatous staghorn-like vascular pattern. Mitotic figures, atypical structures, necrosis and hemorrhage were not identified. No adjuvant therapies were given postoperatively. The patient has been free of tumor recurrence for 25 months since the surgery. IHC revealed that the tumor diffusely expressed CD34, CD99, Bcl2, PAX8, NAB2, STAT6, and GRIA2. The tumor stained negatively for desmin, S-100, c-Kit, CK-AE1/AE3, CDK4 and MDM2. A NAB2-SATA6 gene fusion was detected in tumor cells by reverse transcription-polymerase chain reaction, direct sequencing, and an in situ proximity ligation brightfield assay. The gene fusion occurred as an 831 bp truncation of exon 2 in NAB2 connected to the beginning of exon 3 in STAT6. We have reported a case of GRIA2 and PAX8-positive SFT occurring primarily in the kidney with such NAB2-STAT6 gene fusion for the first time. Diffuse expression of PAX8 in the tumor might present with a renal origin. Reportedly, benign histology of SFT cannot necessarily predict favorable clinical prognosis. Genetic alterations recently identified in SFT could possibly refer to risk stratification for tumor recurrence. However, malignant preponderance of extrathoracic SFT over thoracic SFT remains unexplained so far. Long-term follow-up after surgery should be performed in the present case.

[A case of intraorbital solitary fibrous tumor resected successfully with preoperative arterial embolization]

The solitary fibrous tumor (SFT) is a rare spindle cell neoplasm derived from mesenchymal cells. It sometimes recurs clinically, and is categorized as an 'intermediate malignancy' tumor under the WHO (World Health Organization) classification of soft tissue tumors. Several studies have reported on intraorbital SFTs, but none of them has pointed out the utility of preoperative arterial embolization in the case of an intraorbital SFT. A 75-year-old man, who had received a dacryocystectomy for a benign tumor in the right lacrimal sac 30 years previously, visited our hospital complaining of lower eyelid swelling and lachrymation that had persisted for a year. CT and MRI revealed an intraorbital lesion, and the open biopsy specimen showed dense growth of spindle cells, which turned out to be an SFT by immunohistochemistry based on the findings. After preoperative embolization of the infraorbital artery, we removed the tumor with a skin incision on the lower rim of the orbit with little bleeding. The surgical specimen revealed that the tumor was close to a lacrimal canaliculus, which suggested the tumor originated from the lacrimal apparatus considering the patient's past history. He was followed up for three months without recurrences.

Primary cardiac solitary fibrous tumors

Primary cardiac solitary fibrous tumors were reviewed. They are classified as pericardial tumors. Their incidences are very rare. Only 16 cases were reported in the literature. Basically, surgical treatments are performed. Their prognoses are generally good, although malignant cases are also reported.

Lipomatous hemangiopericytoma in a child: A case report with immunohistochemical evaluation

Lipomatous hemangiopericytomas are rare soft-tissue tumors that show areas of hemangiopericytoma like vascular pattern admixed with lipid containing cells. It is now considered a subtype of solitary fibrous tumor due to histopathological and immunohistochemical similarities. To date, only a few cases have been adequately reported in the medical literature. A case of lipomatous hemangiopericytoma in an 11-year-old female patient is presented and the clinical, histopathological and immunohistochemical features are discussed, along with a literature review. To the best of our knowledge, this is the first known case of a lipomatous hemangiopericytoma in a pediatric patient. Our case report further emphasizes that a number of studies should be evaluated to delineate hemangiopericytomas from solitary fibrous tumors.

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

The objective of this study is to analyze the outcome of treatment for solitary fibrous tumors (SFTs) in the head and neck area. SFTs present as slow-growing masses, often with local compressive symptoms that are difficult to distinguish from other soft-tissue tumors. SFTs are commonly treated using local excision without adjuvant therapy. To date, only heterogeneous small series have been published, documenting the treatment results and outcome with these tumors. Retrospective study of patients with histopathologically confirmed SFT treated at two tertiary referral hospitals between 2004 and 2014. Eight men and four women with histologically confirmed SFT were identified in the records. Their age range was 37-82 years (mean 57.8 years). The mean follow-up period for eight patients was 6.75 years (range 1-24 years). Four patients were lost to follow-up. Sublocalizations were neck (n = 3), orbit (n = 2), paranasal sinus (n = 2), cheek (n = 2), hard palate (n = 1), parotid gland (n = 1), and tongue (n = 1). The first-line treatment for all of the tumors identified was surgical excision. In four cases, the surgical margins were narrow or unclear due to piecemeal resection in the paranasal sinus and orbit (n = 3) or a tumor location deep in the parapharyngeal space (n = 1). Recurrences developed in two of these cases (in the orbit and parapharyngeal space), and the other two patients were lost to follow-up. Radiotherapy and chemotherapy were not administered as first-line treatments. Overall, the local recurrence rate (n = 2/8) was 25 %. The disease-specific survival rate was 100 %. These results are consistent with the literature data and show that safe surgical excision, without opening of the tumor capsule, reduces the risk of local recurrence and leads to a favorable outcome. Tumors in the head and neck often represent a surgical challenge, and wide surgical margins are rarely possible due to the complex three-dimensional anatomic compartments in the region. Head and neck surgeons should therefore be aware that there is an increased risk of recurrence in these patients; tightly scheduled follow-up visits are mandatory for at least 10 years, if not longer. Radiotherapy only appears to be an option in patients with unresectable tumors or when wide surgical excision would cause severe functional morbidity.

Malignant solitary fibrous tumor of the thyroid: a case-report and review of the literature

Solitary fibrous tumor (SFT) is an uncommon spindle-cell neoplasm that most often involves the pleura, rarely occurring in extra-thoracic locations. Twenty-six cases of SFT arising in the thyroid gland have been described. We report a case of a 60-year-old woman presenting an 8-month history of enlargement of the neck associated with dysphagia. The patient underwent a right hemithyroidectomy and SFT of the thyroid was diagnosed. Immunohistochemistry showed positivity for CD34 marker, and the high number of mitoses and the presence of cellular atypia suggested that the tumor was malignant. To our knowledge, this is the second case of malignant SFT of the thyroid gland ever reported. Due to the rarity of these tumors, the indication of adjuvant therapy and prognosis are uncertain. Long-term follow-up after surgical resection seems to be advisable.

Intradural solitary fibrous tumor of the lumbar spine: a distinctive case report

Background. Solitary fibrous tumors are ubiquitous mesenchymal neoplasms of putative fibroblastic origin. They were originally described in the pleura but subsequently have been reported in many extraserosal sites. Solitary fibrous tumors may also occur in the meninges, central nervous system parenchyma, and spinal cord. Case. A 67-year-old male patient with progressive lower extremity weakness, urinary urgency, and sexual dysfunction has been admitted to our hospital. On his lumbar MRI, we detected an intradural lesion posterior to the L3 vertebral corpus. We resected the lesion by L3 total laminectomy. Immunohistological findings revealed strong and diffuse immunopositivity with vimentin, CD34, and bcl-2. Ki-67 proliferation index was 5–8%. We did not detect any recurrence 12 months after his operation. Conclusion. SFT is mostly seen in young and middle-aged patients and should be considered among differential diagnosis in cases suffering from pain, hypoesthesia, and urinary dysfunction. Gross total resection should be primary treatment. Tumors that have high Ki-67 labeling should be followed up for potential recurrences.

Pazopanib as first line treatment for solitary fibrous tumours: the Royal Marsden Hospital experience

Background

Solitary Fibrous Tumour (SFT) is a rare soft tissue neoplasm, described in several locations in the body. It is classified as intermediate malignant potential with low risk of metastasis and has a low tendency to recur after primary surgery.

Methods

We performed a prospective data collection of the patients with SFT presented to the Royal Marsden Hospital from January to December 2013, and treated with pazopanib in first line. Demographics, anatomic primary sites, treatment and survival outcomes were collected from patients’ electronic records.

Results

13 patients (54% females) were identified with a median age of 51 years (range 37–77). Most of the patients (77%) were diagnosed with extra-thoracic SFT. All the patients received first line treatment with pazopanib for metastatic disease. Median overall survival (OS) was 13.3 months. Median progression free survival (PFS) was 4.7 months. No statistically significant difference was found in OS and PFS between primary thoracic SFT and primary extra-thoracic SFT. According to RECIST, one partial response (9%) and eight disease stabilizations (73%) were found as best responses. Using Choi criteria, there were 5 partial responses (46%) and 4 stabilizations (36%).

Conclusion

Our prospective data confirm that anti-angiogenic drugs are active in SFT. PFS and overall response do not appear significantly lower than other reported series on the same disease. Furthermore, pazopanib is a drug already licensed in soft tissue sarcomas and these data suggest its activity also in this particular subtype of sarcomas.

Intraperitoneal solitary fibrous tumor

Solitary fibrous tumors of the pelvis are rare. We report the case of a 32-years-old patient who presented with abdominopelvic mass. The imaging studies showed a right adnexal mass of more than 10 cm. Exploratory laparotomy revealed a 20 cm mass at the Douglas pouch which was adhered to the posterior wall of the uterus. Complete resection of the mass was performed. Histological analysis showed a spindle cell undifferentiated tumor whose morphological and immunohistochemical profile are consistent with solitary fibrous tumor. It is important to know that although these tumors are rare, their evolution can be pejorative. Therefore, long-term followup should be recommended.

Adaptive immune contexture at the tumour site and downmodulation of circulating myeloid-derived suppressor cells in the response of solitary fibrous tumour patients to anti-angiogenic therapy

Background:

Host immunity is emerging as a key player in the prognosis and response to treatment of cancer patients. However, the impact of the immune system and its modulation by therapies are unknown in rare soft tissue sarcomas such as solitary fibrous tumours (SFTs), whose management in the advanced forms includes anti-angiogenic therapy. Here, we studied the in situ and systemic immune status of advanced SFT patients and the effects of sunitinib malate (SM) in association with the clinical efficacy.

Methods:

Immune contexture of SFTs was assessed by immunohistochemistry in lesions from untreated or SM-treated patients. Frequency of circulating myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs) and T-cell functions was assessed ex vivo in SFT patients prior and during anti-angiogenic therapy. Patients with long-term tumour control were included to correlate immune profiles and clinical responses.

Results:

Anti-angiogenic naïve SFT lesions were heavily infiltrated by CD163⁺CD14⁺CD68⁻ and CD163⁺CD14⁻CD68⁻ myeloid cells but devoid of T cells. Conversely, post-SM tumours acquired a new subset of CD68⁺CD14⁺ myeloid cells and displayed traits of an on-going adaptive immunity, strongly enriched in activated CD8⁺ and CD4⁺ T cells. These changes at the tumour site paralleled the alleviation of systemic immunosuppression and the drop in the frequency of circulating monocytic MDSCs (mMDSCs) and granulocytic MDSCs (gMDSCs). Rebound in the number of mMDSCs, but not of gMDSCs occurred at disease progression, and a reduced percentages of mMDSCs, comparable to those found in healthy donors (HDs), endured only in the SM-responsive patients.

Conclusions:

The immune contexture of SFT patients is heavily involved in anti-angiogenic therapy and it could be exploited to achieve more durable disease control through immune-based combination strategies.

Subcutaneous Solitary Fibrous Tumor

We describe a unique case of subcutaneous solitary fibrous tumor (SFT) in a 56-year-old female patient. The patient had been aware of a painless soft mass in her back for ten years. The lesion was surgically excised. Histological examination revealed that the well-defined mass was composed of a proliferation of spindle-shaped fibroblastic cells and polygonal cells embedded in a fibrous matrix corresponding to the so-called "patternless pattern". A prominent pericytomatous pattern (hemangiopericytoma-like structures), focal myxoid changes, and thick hyalinized collagen fibers were also observed. Immunohistochemical stainings for CD34 and bcl-2 were positive in the tumor cells. These features are compatible with SFT. We suggest that SFT should be included in the differential diagnosis of subcutaneous spindle cell tumors.

Giant solitary fibrous tumor of the parotid gland

Solitary fibrous tumors (SFTs) are rare tumors that are mostly found arising from the pleura. SFT of the parotid gland is a rare tumor; only a few cases have been described in the literature. SFTs are benign in most cases. Clinically, SFTs usually manifest as well circumscribed, slow-growing, smooth, and painless masses. CT-Scan and MRI are the most sensitive imaging procedures used. The treatment of choice is complete surgical excision of the lesion. Since recurrence and metastasis can take place after several years, a lifelong clinical and imaging regular follow-up is compulsory. In this paper, we describe the diagnostic and therapeutic challenges of the up-to-now biggest parotid SFT. The clinical presentation, surgical management, and pathological and immunohistochemistry findings are described.

A huge malignant solitary fibrous tumor of kidney: case report and review of the literature

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1603694556107408.

Solitary fibrous tumor (SFT) is a spindle cell neoplasm that rarely occurs in the kidney. Malignant SFT of the kidney is particularly rare. Here, we report a 66-year old woman with a right flank mass that has been proved clinically and radiographically. Grossly, the largest diameter of the mass were measured up to 23 cm, was poorly circumscribed. Approximately 80% of the neoplasm consisted of hyperchromatic and pleomorphic spindled cells surrounding staghornlike blood vessels. Tumor cells frequently had mitoses and necrosis. However, the remainder of the mass was composed of haphazard, storiform or short fascicular arrangements of spindle cells in a loose myxoid to fibrous stroma. Immunohistochemically, we observed diffusely strong CD34 staining and an 85% Ki-67 proliferative index. The tumor partly showed negative CD34 and a 20% proliferative index. To our knowledge, this is the largest malignant renal SFT in the reported literatures and shows an obviously high proliferative index.