[A Case of Anaplastic Carcinoma with Osteoclastlike Giant Cells of the Pancreas Concomitant with Lung Recurrence of Solitary Fibrous Tumor].

A 32-year-old woman presented with epigastric pain and an abdominal mass. Abdominal CT showed a 130mm pancreatic tail mass with an enhanced rim, central necrosis, and small calcification. A 6mm lung tumor was also found via chest CT. Her medical history included surgical resection of cerebral solitary fibrous tumor when she was 24 years old. When she was 31 years old, it had recurred but was cured by gamma knife radiosurgery. We performed distal pancreatectomy and splenectomy with lymph node dissection. According to pathological and immunohistochemical findings, it was diagnosed as an anaplastic carcinoma with osteoclast-like giant cells. She underwent surgical resection of the lung tumor 2 months after pancreatic resection and was diagnosed with metastasis from the solitary fibrous tumor. Fourteen months since undergoing pancreatectomy, the patient experienced no recurrence from both diseases. We report a rare resected case of anaplastic carcinoma of pancreas concomitant with recurrent solitary fibrous tumor.

A DSTYK mutation activates ERK1/2 signaling to promote intraspinal dissemination in a case of solitary fibrous tumor/hemangiopericytoma.

Intracranial solitary fibrous tumors/hemangiopericytomas (SFT/HPCs) are vascular tumors that have a high rate of local recurrence and extracranial metastases. Intradural extramedullary spinal dissemination of intracranial SFT/HPC is extremely rare. There is a paucity of data available to elucidate the molecular mechanisms of intraspinal dissemination of intracranial SFT/HPC. Herein, we presented a case of intracranial SFT/HPC with intraspinal metastasis. The resected tumor specimens were enrolled in a clinical sequencing program, including whole-exome and transcriptome sequencing. By comparing genomic sequencing data of the intracranial tumors with intraspinal metastasis, we established the somatic mutational profiles of these tumors. Clonality analysis revealed a distinct subclonal structure in the intracranial tumor and its intraspinal metastasis, which might reflect the possibility of intratumoral clonal selection and evolution during the process of tumor dissemination. Through bioinformatics analysis and Sanger sequencing validation, a DSTYK mutation (Met296Ile) was identified as a candidate driver of intraspinal metastasis in this SFT/HPC case. Further, an intracranial tumor-derived SFT/HPC cell line, HPC3, was established to explore the mechanisms of the DSTYK mutation in promoting SFT/HPC metastasis. Based on the HPC3 cell model, we found that the DSTYK mutation promoted cell migration and invasion of HPC3 cells via activation of ERK1/2 signaling, which was inhibited by the MEK/ERK inhibitor AZD6244. The DSTYK mutation was also shown to upregulate the expression of two metastasis-related molecules: MMP2 and MMP9 in HPC3 cells; however, this effect was attenuated by AZD6244 treatment. Therefore, the DSTYK mutation may activate ERK1/2/MMP2/9 signaling to promote tumor cell metastasis in SFT/HPC. In conclusion, our study revealed the potential role of DSTYK mutation in the regulation of intraspinal metastasis of SFT/HPC, which might provide new biological insights into this rare disease.

Metastatic Solitary Fibrous Tumour of the Kidney Presenting more than a Decade Later with Pulmonary Disease

Introduction Solitary fibrous tumours are rare mesenchymal tumours that most commonly originate from the visceral pleura. Extra-thoracic primary sites including; head and neck, soft tissue, retroperitoneum and the urological tract, are associated with late recurrence. Case We present a case of metastatic pulmonary Solitary Fibrous Tumour presenting 11 years post resection of renal primary Solitary Fibrous Tumour. The patient underwent apical segmentectomy of the right lower lobe extending to wedge excision of right upper lobe due to fissure involvement with lymphadenectomy. The patient was discharged day 12 post surgery. Discussion Robust guidance regarding long-term management of solitary fibrous tumours is lacking. Salvage resection offers favourable long-term prognosis. This case demonstrates the importance of long-term surveillance.

Tumor-to-tumor metastasis of lung adenocarcinoma into a spinal intradural solitary fibrous tumor: a case report.

Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms commonly involving visceral or parietal pleura. We present the first report of tumor-to-tumor metastasis involving a pulmonary adenocarcinoma donor and an intradural SFT recipient. The patient presented with a 1 year history of diffuse back pain. A spinal intradural contrast-enhancing mass at the T9/10 level and a tumor of the lung were diagnosed radiologically. Bronchoscopic biopsy confirmed pulmonary adenocarcinoma in the right upper lung lobe. Due to deteriorating neurological status with conus medullaris syndrome, we performed a neurosurgical excision of the lesion. Histological analysis of the tumor revealed tumor-to-tumor metastasis of the adenocarcinoma to the SFT.

Metastatic Patterns of Solitary Fibrous Tumors: A Single-Institution Experience.

OBJECTIVE: The objective of our study was to evaluate the metastatic patterns and imaging features of solitary fibrous tumors (SFTs). MATERIALS AND METHODS: This retrospective study included 139 patients with pathologically proven SFT, 49 of whom developed metastases. Electronic medical records and all available images were reviewed to record the pattern and imaging appearances of metastatic disease, and comparisons of thoracic SFTs and extrathoracic SFTs were also performed. Associations of metastatic spread were studied using univariate and multivariate Cox regression analyses. RESULTS: A total of 49 (35%) patients developed metastases at a median of 124 months (interquartile range [IQR], 66-195 months) after SFT diagnosis; 11 patients (8%) had metastases at presentation. Of these 49 patients, 40 patients died at a mean of 183 months after diagnosis. The associations with metastatic disease on univariate analysis were tumor size ≥ 10 cm (p = 0.01) and malignant pathology or mitotic count ≥ 4 per 10 high-power fields (HPF) (p < 0.001). Malignant pathology and a mitotic count of ≥ 4 per 10 HPF were also associated with metastatic disease on multivariate analysis (p = 0.01; hazard ratio, 0.22; 95% CI, 0.05-0.73). The most common sites of metastasis were the lungs (30/49, 61%) followed by the pleura (24/49, 49%) and then the liver (20/49, 41%), bones (20/49, 41%), and peritoneum (20/49, 41%). A significantly higher proportion of patients with extrathoracic SFT had metastatic disease (37/139, 27%) compared with those with thoracic SFT (12/139, 9%) (p = 0.003). The overall metastasis-free survival was a median of 117 months (IQR, 33-169 months) in patients with extrathoracic SFT and a median of 120 months (IQR, 82-169 months) in patients with thoracic SFT (p = 0.01). CONCLUSION: A mitotic count of ≥ 4 per 10 HPF or malignant pathology was significantly associated with metastatic disease on both univariate and multivariate analyses. The sites of metastatic disease differed depending on the site of the primary SFT but were most commonly the lung and pleura. Patients with extrathoracic SFT were statistically more likely to develop metastatic disease than those with thoracic SFT.

Solitary fibrous tumour of the liver-report on metastasis and local recurrence of a malignant case and review of literature.

BACKGROUND: Solitary fibrous tumours (SFT) are neoplasms of mesenchymal origin that predominantly arise from the pleura. SFT of the liver (SFTL) are a rare occurrence with little number of cases reported in English literature. Malignant cases of hepatic SFT are an even rarer occurrence. For this reason, the prognostic evaluation of SFTLs is unknown and difficult to measure. METHODS: A search on English literature on "Solitary Fibrous Tumour of the Liver" was conducted on common search engines (PubMed, Google). All published articles, case reports and literature reviews and their reference lists were reviewed. CASE REPORT: This paper presents a 61-year-old male who was referred to a tertiary hospital in April 2010 with marked hepatomegaly. USS, CT and MRI scans were suggestive of a neoplasm, and the patient underwent a subsegmental IVb resection in June 2010. The specimen demonstrated histological and immunohistochemical features of malignant SFTL with clear resection margins. The patient was followed up regularly for 3 years with imaging and no suggestion of recurrence. Six years after the initial surgery, the patient represented with worsening right upper quadrant pain and dyspnoea secondary to extensive tumour recurrence adjacent to the resection site and metastatic deposits in the pleura. The patient was managed symptomatically and discharged for community follow-up after palliative involvement. CONCLUSIONS: SFTL are rare with only 84 cases reported in the English Literature including the present case. The average age of patients is 57.1 and occurs in females more than males (1.4:1). Most SFTLs follow a benign course, however, 17.9% of cases displayed malignant histological features. Only three cases including the current case are reported to have both local recurrence and metastasis. Surgical resection remains the mainstay of treatment and appears to be curative of most cases. The rarity of this tumour makes it difficult to evaluate its prognosis and natural course.

Solitary Fibrous Tumor of the Uterus Presenting With Lung Metastases: A Case Report.

We describe the case of an 81-yr-old woman who presented with bilateral pulmonary nodules in the setting of a large uterine mass, concerning for a gynecologic malignancy such as leiomyosarcoma. However, fine-needle aspiration of a lung nodule revealed a spindle cell neoplasm consistent with solitary fibrous tumor (SFT), a rare mesenchymal neoplasm characterized by a patternless architecture of spindle cells and branching ectatic vessels. Total abdominal hysterectomy demonstrated a primary SFT of the uterus. Both the lung lesion and uterine mass were positive for STAT6, a sensitive and specific biomarker for SFT. SFT infrequently metastasizes and only rarely occurs in the uterus. These tumors are considered to have uncertain malignant potential, and the diagnosis of "malignant" SFT requires the presence of >4 mitoses per 10 high-power fields. The uterine SFT we report did not meet this criterion for malignancy, emphasizing that this entity can behave aggressively even without increased mitoses or atypical histology. To our knowledge, this is the first reported case of a uterine SFT with metastasis to the lung. We discuss the differential diagnosis for the finding of multiple pulmonary spindle cell lesions in the setting of a uterine mass.

Malignant metastasizing solitary fibrous tumors of the liver: a report of three cases.

Solitary fibrous tumors are rare neoplasms of mesenchymal origin that have been reported in various other extrathoracic sites, including the liver. We present a case series of three malignant solitary fibrous tumors of the liver, occurring in two women 74 and 80 years old and one 65-year-old man. No clinical features were predictive of malignancy except the large sizes and synchronous presence of lung metastases in two of the three cases. Histological examinations revealed the presence of high pleomorphic cellularity with nuclear atypia, necrosis and high mitotic ratios. All patients died of disease progression.

Pancreatic metastasis from a solitary fibrous tumor of the central nervous system.

CONTEXT: Solitary fibrous tumor of the central nervous system is uncommon, with only around 200 reported cases. Further, extracranial metastasis is extremely rare, and only 5 cases of hematogenous metastases have been reported so far. To the best of our knowledge, there have been no reports of solitary fibrous tumor of the central nervous system metastasizing to the pancreas. CASE REPORT: A 62-year-old woman was referred for evaluation of a pancreatic mass, which was strongly suspected to be a neuroendocrine tumor. However, the histological findings and immunohistochemical profile indicated the presence of a solitary fibrous tumor. Because the medical history revealed previous transcranial resection for intracranial meningioma 16 years ago, we conducted a pathological review of the brain specimen obtained by the first operation and found that it had the same histology and immunohistochemical profile as the current endoscopic ultrasound-guided fine-needle aspiration specimen. Consequently, the final diagnosis, on the basis of the brain specimen, was changed from meningioma to solitary fibrous tumor of the central nervous system, and the pancreatic mass was diagnosed as metastasis from solitary fibrous tumor of the central nervous system. The patient underwent middle pancreatectomy; the pancreatic specimen also had the same histology and immunohistochemical profile as the brain specimen. CONCLUSION: Histological findings and immunohistochemical profile obtained by EUS-FNA are invaluable for the correct diagnosis to avoid excessive surgical procedures.

Pancreatic metastasis from a solitary fibrous tumor of the kidney: a rare cause of acute recurrent pancreatitis.

Solitary fibrous tumors are unusual spindle cell neoplasms that uncommonly originate from the kidney. We report a case of a 43-year old male who presented with acute recurrent pancreatitis secondary to a mass in the head of the pancreas. Endoscopic ultrasound with fine needle aspiration (EUS-FNA) was performed. Cytology revealed solitary fibrous tumor of the kidney. This is the first reported case of solitary fibrous tumor metastasizing to the pancreas and presenting as acute recurrent pancreatitis.

Extracranial metastasizing solitary fibrous tumors (SFT) of meninges: histopathological features of a case with long-term follow-up.

Extrapleural solitary fibrous tumors are uncommon mesenchymal neoplasms frequently observed in middle-aged adults and are classified, according to the WHO classification of soft tissue tumors, as part of the hemangiopericytoma tumor group. However, these two entities remain separated in the WHO classification of tumors of the central nervous system. In fact, meningeal solitary fibrous tumors are believed to be benign lesion and only in a minority of cases local relapses have been described, although detailed survival clinical studies on solitary fibrous tumors of meninges are rare. In contrast to hemangiopericytoma, which frequently shows distant extracranial metastases, such an event is exceptional in patients with meningeal solitary fibrous tumors and has been clinically reported in a handful of cases only and their histopathological features have not been investigated in detail. In this report, we describe the detailed clinico-pathological features of a meningeal solitary fibrous tumor presenting during a 17-year follow-up period, multiple intra-, extracranial relapses and lung metastases.

Biphasic solitary fibrous tumor of the orbit with distant metastases.

The aim of this study is to report the first case of biphasic solitary fibrous tumor (SFT) of the orbit with documented histological transformation and metastatic diffusion. We describe a case of a 23-year-old Caucasian man with recurrent SFT of the right orbit with intracranial invasion. The patient underwent surgical tumor removal via a right fronto-orbital approach. Histopathological examination showed a biphasic tumor pattern with both spindle cell and epithelioid components. The histopathological re-evaluation of previously removed lesions (1999 and 2004) confirmed the diagnosis of SFT, without any evidence of epithelioid component at that time. The patient developed local recurrence and systemic metastases (occipital foramen and clivus, paravertebral muscles and peritoneum) three years after surgery. We are unaware of previous reports of biphasic solitary fibrous tumor of the orbit with documented histological transformation and metastatic diffusion.

Solitary fibrous tumor of the kidney with massive retroperitoneal recurrence. A case presentation.

Solitary fibrous tumor is an unusual spindle cell neoplasm that usually occurs in the pleura but has also been described in other sites. Renal presentation is rare and only 38 cases of SFT of the kidney have been described until now. Up to 90% of the tumors have benign characteristics. Local retroperitoneal recurrence is extremely rare. We report a case of a large malignant solitary fibrous tumor recurrence after the surgical excision of the primary tumor. Histological examination of the specimen confirmed the diagnosis by revealing highly positive reaction of the neoplasmatic cells for vimentin, CD34, bcl-2 and moderately positive for actin. The rate of Ki67 lied between 2-7%. No adjuvant therapy was given to the patient and he is disease-free with no imaging findings of recurrence or metastasis 9 months after the re-operation.

The many faces of solitary fibrous tumor; diversity of histological features, differential diagnosis and role of molecular studies and surrogate markers in avoiding misdiagnosis and predicting the behavior.

BACKGROUND: Solitary Fibrous Tumor (SFT) is a distinct soft tissue neoplasm associated with NAB2-STAT6 gene fusion. It can involve a number of anatomic sites and exhibits a wide spectrum of histological features. MAIN BODY: Apart from diversity in morphological features seen even in conventional SFT, two histologic variants (fat-forming and giant cell-rich) are also recognized. In addition, a malignant form and dedifferentiation are well recognized. Owing to diverse histological features and involvement of diverse anatomic locations, SFT can mimic other soft tissue neoplasms of different lineages including schwannoma, spindle cell lipoma, dermatofibrosarcoma protuberans, liposarcoma, gastrointestinal stromal tumor (GIST), malignant peripheral nerve sheath tumor (MPNST), and synovial sarcoma. SFT is classified as an intermediate (rarely metastasizing) tumor according to World Health Organization Classification of Tumors of Soft tissue and Bone, 5th edition. The management and prognosis of SFT differs from its malignant mimics and correct diagnosis is therefore important. Although SFT expresses a distinct immunohistochemical (IHC) profile, the classic histomorphological and IHC profile is not seen in all cases and diagnosis can be challenging. NAB2-STAT6 gene fusion has recently emerged as a sensitive and specific molecular marker and its IHC surrogate marker signal transducer and activator of transcription 6 (STAT6) has also shown significant sensitivity and specificity. However, few recent studies have reported STAT6 expression in other soft tissue neoplasms. CONCLUSION: This review will focus on describing the diversity of histological features of SFT, differential diagnoses and discussing the features helpful in distinguishing SFT from its histological mimics.

A not so solitary fibrous tumor of the liver.

Solitary fibrous tumor (SFT) is a rare neoplasm. Liver parenchyma is a rare location of SFT and, in this case, it usually follows a benign course. We report here the case of a 54-year-old man who presented a large SFT tumor of the right hepatic lobe. The tumor was surgically resected. Local recurrence occurred 6 years later as a 15 cm diameter liver tumor. Histological examination of the resected lesion showed features of an aggressive form of SFT. Two years later, the patient presented with complaints of neck pain and ensuing examinations revealed a tumor of the cranial base. A new surgical resection was performed and histological examination confirmed a metastasis of the SFT. Few weeks later, the patient presented an irreducible psoitis due to an iliac bone metastasis. He died within 1 month.

Solitary fibrous tumor involving the pancreas: report of the cytologic features and first report of a primary pancreatic solitary fibrous tumor diagnosed by fine-needle aspiration biopsy.

INTRODUCTION: Solitary fibrous tumor (SFT) of the pancreas is rare, with only 16 reported cases in English studies. The cytologic features of pancreatic SFT have not been well described. We report 2 cases of SFT (1 primary and 1 metastatic) involving the pancreas and discuss the cytomorphologic findings, including the first primary SFT of the pancreas specifically diagnosed using cytology. MATERIALS AND METHODS: The cases of 2 patients with a diagnosis of SFT of the pancreas from material obtained via fine needle aspiration (FNA) are reported. Clinical information was retrieved from the patients' medical records. The FNA cytology slides, previous relevant surgical pathologic findings, and findings from subsequent pancreatic resections were reviewed. RESULTS: Of the 2 patients, 1 had had secondary involvement of the pancreas from a primary central nervous system SFT, and 1 had had a primary pancreatic SFT diagnosed by FNA. Immunohistochemistry for STAT6 was crucial for establishing the diagnosis using FNA. CONCLUSIONS: We have reported 2 cases of SFT involving the pancreas, including the first reported case of primary pancreatic SFT diagnosed preoperatively using FNA. Metastatic SFT from central nervous system primaries should be considered when diagnosing SFT of the pancreas.

Solitary fibrous tumors of the head and neck region revisited: a single-institution study of 20 cases and review of the literature.

A solitary fibrous tumor (SFT) is a rare, NAB2-STAT6 fusion gene-associated mesenchymal neoplasm. It most commonly arises in the pleural site, but it can occur at many other sites, and rarely also in the head and neck (H&N) region. STFs may show many growth patterns and therefore can be easily mistaken for other more common H&N spindle cell or epithelial lesions. In this study, we present our experience in the diagnosis of 20 cases of SFT in the H&N region and discuss their most notable mimickers. In all cases, STAT6 expression was found positive by immunohistochemistry, and the NAB2-STAT6 fusion was confirmed by next-generation sequencing. Three major fusion variants were detected: NAB2ex2-STAT6int1 (5/20, 25%), NAB2ex6-STAT6ex16 (4/20, 20%), and NAB2ex4-STAT6ex2 (3/20, 15%). Clinical follow-up was available for 16 patients (median follow-up time: 84 months). One patient with a morphologically malignant SFT experienced multiple local recurrences, followed by dissemination into the lungs and meninges. This malignant SFT also displayed an aberrant FLI1 expression, which was not previously reported in SFT cases. We also summarize findings from 200 cases of SFT of the H&N region, which included cases from our study, and from previous studies that reported on the fusion status of the STAT6 gene. The results suggest that metastatic disease developed only in cases with STAT6 variants that included the DNA-binding domain (STAT6-full variants), which contradicts expectations from previous reports and deserves further investigation.

Peritoneal solitary fibrous tumour (SFT): long-term survival of recurrent and metastasised SFT treated with cytoreductive surgery and intraperitoneal chemotherapy.

This study reports a case of a SFT of the peritoneum in a 44-year-old white man that recurred 3 years after the initial surgical removal of the tumour. The patient recurred diffusely, developing a pattern of sarcomatosis and hepatic metastasis and was treated by surgical cytoreduction followed by intraoperative peritoneal hyperthermic chemotherapy (IPHC). Subsequently, he developed pulmonary metastases and was treated with palliative chemotherapy. The patient persisted with recurrent and distant disease, although it was reduced and stabilised, allowing his survival for the last 3 years since the extended surgery. New treatment strategies for a rare disease such as this one have first to be described in order to improve patient follow-up.