Solitary fibrous tumors in abdomen and pelvis:Imaging characteristics and radiologic-pathologic correlation

AIM: To describe the imaging features of solitary fibrous tumors (SFTs) in the abdomen and pelvis, and the clinical and pathologic correlations.

Solitary fibrous tumor:A case report of this multifaceted tumor

BACKGROUND Solitary fibrous tumor(SFT)is a remarkably uncommon mesenchymal tumor.STAT6 level and a combination of clinical,pathological,and molecular features are required to arrive at a proper diagnosis.CASE SUMMARY In this report,we present an intriguing case involving a 43-year-old woman who initially exhibited symptoms of a bleeding retroperitoneal tumor,initially resembling a gastrointestinal stromal tumor,but later confirmed as an SFT.However,a year later,what was initially believed to be a recurrence of her SFT was instead identified as a desmoid tumor.CONCLUSION Distinguishing SFT from other tumors was pivotal.Correcting misdiagnoses of tumor type initially and of recurrence later was necessary for appropriate treatment of the correct desmoid type.

Metastatic pancreatic solitary fibrous tumor: A case report

BACKGROUND Solitary fibrous tumor(SFT)is a rare mesenchymal tumor that is most commonly found in the pleura but can also originate from non-pleural sites.Among the nonpleural localizations,the pancreas is extremely rare.In particular,metastasis to the pancreas from the central nervous system(CNS)is extremely rare,with only two cases reported so far.We report a case of recurrence in the pancreas 14 years after the initial complete surgical removal of a tumor in the CNS.CASE SUMMARY A 68-year-old man with a past medical history of recurrent meningeal hemangiopericytoma,currently referred to as SFT,presented to the hospital with jaundice.The patient was first diagnosed with an 8cm-sized meningeal hemangiopericytoma fourteen years ago and underwent osteoplastic craniotomy.After 16 mo,imaging showed recurrence and he underwent gamma knife radiosurgery(GKRS).2 years later,imaging showed recurrence again leading to a second GKRS.5 years later,recurrence was again suspected leading to a second craniotomy.Since then 3 years had passed,and imaging showed a 3.5cm-sized mass lesion on the pancreatic head with obstruction of the pancreatic and bile ducts.Endosonography with fine-needle aspiration biopsy was done preoperatively and aided in the diagnosis of SFT.The patient underwent pyloruspreserving pancreaticoduodenectomy.Pathologic findings of the resected pancreatic specimen,consistent with the previously resected brain specimen,confirmed the diagnosis of SFT.CONCLUSION The rarity and lack of knowledge about SFTs make suspecting and diagnosing this disease challenging.We believe that a report of metastatic pancreatic SFT from the CNS will contribute to a better understanding of this rare disease.

Giant solitary fibrous tumor arising from greater omentum

Extrathoracic solitary fibrous tumors(SFTs) have been described at almost every anatomic location of human body,but reports of SFT in the abdominal cavity are rare.We herein present a rare case of SFT originating from greater omentum.Computed tomography revealed a 15.8 cm × 21.0 cm solid mass located at superior aspect of stomach.Open laparotomy confirmed its mesenchymal origin.Microscopically,its tissue was composed of non-organized and spindle-shaped cells exhibiting atypical nuclei,which were divided up by branching vessel and collagen bundles.Immunohistochemical staining showed that this tumor was negative for CD117,CD99,CD68,cytokeratin,calretinin,desmin,epithelial membrane antigen,F8 and S-100,but positive for CD34,bcl-2,α-smooth muscle actin and vimentin.The patient presented no evidence of recurrence during follow-up.SFT arising from abdominal cavity can be diagnosed by histological findings and immunohistochemical markers,especially for CD34 and bcl-2 positive cases.

Solitary fibrous tumor of the liver expressing CD34 and vimentin:A case report

A case of a successfully treated solitary fibrous tumor (SFT) of the liver is reported.An 82-year-old female presented with left upper abdominal discomfort,a firm mass on palpation,and imaging studies revealed a large tumor,15 cm in diameter,arising from the left lobe of the liver.A formal left hepatectomy was performed.Microscopic evaluation showed spindle and fibroblast-like cells within the collagenous stroma.Immunohistochemistry disclosed diffuse CD34 and positive vimentin,supporting the diagnosis of a benign SFT.The patient remained well 21 months after surgery.SFT of the liver is a very rare neoplasm of mesenchymal origin.In most cases it is a benign lesion,although some may have malignant histological features and recur locally or metastasize.With less than 30 reported cases in the literature,little can be said regarding its natural history or the benefits of adjuvant radiochemotherapy.Complete surgical resection remains the cornerstone of its treatment.

Doege-Potter syndrome by malignant solitary fibrous tumor of the liver: A case report and review of literature

BACKGROUND Solitary fibrous tumor of the liver (SFTL) is a rare occurrence with a low number of cases reported in literature. SFTL is usually benign but, 10%-20% cases are reported to be malignant with a tendency to metastasize. The majority of malignant SFTL cases are associated with a paraneoplastic hypoglycaemia defined as Doege-Potter syndrome. Surgery is the best therapeutic treatment, however, long- life follow-up is recommended. CASE SUMMARY A 74-year-old man, was admitted to the emergency department after a syncopal episode with detection of hypoglycaemia resistant to medical treatment. The computed tomography revealed a solid mass measuring 15 cm of the left liver. An open left hepatectomy was performed with complete resection of tumor. Histopathological analyses confirmed a malignant SFTL. CONCLUSION Large series with long-term follow-up have not been published neither have clinical trials been undertaken. Consequently, the methodical long-term followup of surgically treated SFTLs is strongly recommended.

Intracranial malignant solitary fibrous tumor metastasized to the chest wall:A case report and review of literature

BACKGROUND Solitary fibrous tumor(SFT)is a rare fibroblastic mesenchymal neoplasm that affects spindle cell soft tissues with broad-spectrum biological behavior;it is predominantly benign,and rarely metastasizes.SFT occurs mainly in the tissue structure of the serosa in the pleura and the thorax,and can be found throughout the body,though extra-thoracic localization,including the cephalic region,is uncommon.We reported the first case of intracranial malignant SFT metastasized to the chest wall.CASE SUMMARY An 81-year-old Japanese man was referred to our hospital due to progressive gait disturbance and appetite loss.His medical history included partial resection due to brain tumor,four times,and 50-Gray radiation therapy at another hospital,starting when he was 74 years old.An unenhanced head computed tomography(CT)scan revealed an 8 cm×5.1 cm×6.5 cm mixed-density mass at the left frontal lobe,accompanying a midline shift,and an unenhanced chest-abdomen CT scan revealed a 6 cm×4.1 cm×6.5 cm low-density mass in the left chest wall.A CT-guided percutaneous lung biopsy was performed,and the pathological findings were SFT corresponding to brain tumor.Finally,the correct diagnosis of his brain tumor in history of past illness revealed to be SFT,and the unremovable tumor,namely present brain lesions enlarged and metastasized to the chest wall.We established a definitive diagnosis of intracranial malignant SFT metastasized to the chest wall.We notified him and his family of the disease,and offered palliative care.He passed away on the 29 th hospital day.CONCLUSION This case suggests the need for careful,detailed examination,and careful followup when encountering patients presenting with a mass.

Obstructive jaundice caused by secondary pancreatic tumor from malignant solitary fibrous tumor of pleura:A case report

A 77-year-old man on systemic chemotherapy against postoperative bilateral multiple lung metastases of malignant solitary fibrous tumor of the pleura suffered from pruritus and jaundice. Blood examination showed elevated levels of hepatobiliary enzymes. Abdominal computed tomography showed a tumor with peripheral enhancement in the pancreatic head, accompanied with the dilatation of intra- and extra-hepatic bile ducts. He was diagnosed as having obstructive jaundice caused by a pancreatic head tumor. The pancreatic head tumor was presumably diagnosed as the metastasis of malignant solitary fibrous tumor of the pleura, because the findings on the pancreatic head tumor on abdominal CT were similar to those on the primary lung lesion of malignant solitary fibrous tumor of the pleura. The pancreatic tumor grew rapidly after the implantation of metallic stent in the inferior part of the common bile duct. The patient died of lymphangitis carcinomatosa of the lungs. Autopsy revealed a tumor that spread from the pancreatic head to the hepatic hilum. Microscopically, spindle-shaped cells exhibiting nuclear atypicality or division together with collagen deposition were observed. Immunohistochemically the pancreatic head tumor cells were negative for staining of α-smooth muscle actin （α-SMA） or CD117, but positive for vimentin, CD34 and CD99. These findings are consistent with those on malignant solitary fibrous tumor of the pleura. We report the first case of obstructive jaundice caused by a secondary pancreatic tumor from malignant solitary fibrous tumor of the pleura.

Malignant solitary fibrous tumor of the pancreas with systemic metastasis: A case report and review of the literature

BACKGROUND Pancreatic solitary fibrous tumor(SFT) is a rare neoplasm of intermediate biological potential. So far, only 22 cases have been reported since 1999. All the cases, except one, exhibited benign features. Here, we report the first case of malignant pancreatic SFT with typical Doege-Potter syndrome, along with the clinical and pathologic evidence of its systemic metastasis.CASE SUMMARY The patient was a 48-year-old man with a 1-year history of pancreatic and liver masses and refractory hypoglycemia. Increased uptake of the tracer fluorodeoxyglucose(FDG) was found in the liver and bones by fluorine-18 FDG positron emission tomography/computed tomography. After multidisciplinary discussion, a distal pancreatectomy procedure was performed, and histological examination showed a lesion composed of abundant heterogeneous spindle cells with localized necrosis. On immunohistochemistry evaluation, STAT6 was found to be diffusely expressed in the tumor. Based on the overall evidence, the patient was diagnosed with malignant pancreatic SFT with liver and bone metastases.CONCLUSION The diagnosis of malignant SFT requires comprehensive evidence including clinical, immunohistochemistry, and histological features. This case may be presented as a reference for diagnoses and management of malignant pancreatic SFTs with systemic metastasis.

Extrapleural solitary fibrous tumor of the thyroid gland: A case report and review of literature

BACKGROUND Solitary fibrous tumor(SFT)is an uncommon mesenchymal neoplasm that arises from the pleura.A few SFTs have also been described in extrapleural sites.However,SFT of the thyroid gland is rare.Here,we report a case of extrapleural SFT on the thyroid gland,in addition to a literature review.CASE SUMMARY A 59-year-old man visited our hospital in July 2017 complaining of a large mass in his neck.His thyroid function test results,including antibody levels,were within the normal limits.Ultrasonography showed a 4.7 cm×4.0 cm×3.2 cm solitary mass of intermediate suspicion in the left thyroid lobe.A fine-needle aspiration biopsy was subsequently performed.The pathologist reported a benign follicular lesion.However,the size of this nodule increased to 5.5 cm×5.0 cm×3.4 cm by April 2018.After a multidisciplinary discussion,a left lobectomy was performed in May 2018.The specimen showed a well-demarcated,partly encapsulated,soft nodule of whitish and tan/brown color on the cut surface.Light microscopy revealed high cellularity with moderate cytologic atypia.The mitotic count was 5/10 high-power fields.There was no tumor necrosis or lymphovascular invasion.The tumor was CD34-positive and signal transducer and activator of transcription 6-positive.Neither thyroid transcription factor-1 nor cytokeratin expression was detected.The Ki-67 showed intermediate proliferative activity.The final diagnosis was extrapleural SFT of the thyroid gland with a clear resection margin.The patient was discharged without complication three days after the surgery.CONCLUSION In the literature,extrapleural SFT of the thyroid gland has been reported to behave indolently with the capacity for recurrence and rare metastasis,although surgical resection is the treatment of choice.Understanding this disease entity is important for accurate diagnosis and proper management.

Solitary fibrous tumor of the liver:A case report and review of the literature

BACKGROUND Hepatic solitary fibrous tumor(SFT)is a rare neoplasm.Up to now,only 90 cases have been reported in the English language literature.This report describes a case of SFT of the liver misdiagnosed as hepatocellular carcinoma.CASE SUMMARY A 42-year-old male had a two-year history of a gradually enlarging intrahepatic nodule.The preoperative imaging revealed a mass with a size of 2.7 cm×2.3 cm located in the segment IV of the liver.The patient was subjected to the resection of the segment IV,such as the medial segment of the left lobe of the liver.The histological examination of the mass showed various spindled cells irregularly arranged in the stroma.The immunohistochemistry of this mass revealed a positive staining for CD34 and STAT6.The history of intracranial tumor and postoperative pathological results led to the diagnosis of SFT of the liver(SFTL)due to a metastasis from the brain.CONCLUSION SFTL is an uncommon mesenchymal neoplasm that can be easily overlooked or misdiagnosed.The best treatment choice is the complete surgical resection of the mass.A regular follow-up after the surgery should be performed due to the poor prognosis of metastatic or recurrent SFT.

Malignant solitary fibrous tumor of the greater omentum: A case report and review of literature

BACKGROUND Malignant solitary fibrous tumors(SFTs)account for 15%-20%of all SFTs,and malignant SFTs arising from the greater omentum are extremely rare.Most malignant SFTs of the greater omentum are diagnosed via pathological examinations after surgery.In this study,we report a case of malignant omental SFT and review the published literature on this rare malignancy.CASE SUMMARY A 64-year-old female presented with an abdominal mass,and underwent exploratory surgery,during which a huge tumor originating from the greater omentum and intraperitoneal implants were identified and resected.The results of the pathological examination,immunohistochemistry staining,and gene sequencing led to the diagnosis of malignant SFT of the greater omentum.The patient died one and a half years later due to tumor recurrence and metastasis.CONCLUSION This is the first report of the application of gene sequencing in the diagnosis of malignant SFTs of the greater omentum.

A Large Solitary Fibrous Tumor of the Mediastinum

Alarge solitary fibrous tumor in an adult woman＇s mediastinum accompanied by distress and shortness of breath is described.We believe that a tumor of this large size in the mediastium has rarely been reported in the world literature.

Solitary fibrous tumor of the liver

BACKGROUND: Solitary fibrous tumor of the liver is a rare neoplasm. So far, 23 cases have been described in the English literature. We reported an additional case. METHODS: A 46-year-old woman presented with abdominal mass for 2 weeks. Both abdominal sonography and CT scan showed a solid mass occupying the right lobe of the liver. Right lobectomy was performed and the tumor was resected. RESULTS: Pathological examination showed spindle cell and fibroblast-like cells within the collagenous troma. On immunohistochemical staining, these spindle tumor cells showed diffusely CD34 positive reactivity. The post-operative course was uneventful. The patient recovered smoothly, and was alive half a year without evidence of disease recurrence. CONCLUSIONS: The proper diagnosis was depended on CD34 immunohistochemical study. The number of solitary fibrous tumor of the liver reported to date is too limited to confirm the definite prognosis of the tumor.

Clinical characteristics and prognosis of orbital solitary fibrous tumor in patients from a Chinese tertiary eye hospital

BACKGROUND Solitary fibrous tumor(SFT) is predominant within the pleura but very rare in the orbit,which is why the diagnosis of orbital SFT poses challenges in clinical practice.Accordingly,an integrated approach that incorporates specific clinical features,histological,histopathological,and immunohistochemical(IHC) examinations,and molecular analyses is warranted.AIM To retrospectively explore the clinical and imaging characteristics,treatment,outcomes of a series of patients with orbital SFT.METHODS We conducted a retrospective review of a series of patients diagnosed with a histopathologic orbital SFT treated at a single institution.All data on demographics,clinical characteristics,imaging,treatment,postoperative histopathological and IHC examinations,and prognosis were collected.RESULTS In total,13 patients were enrolled,7(53.8%) of whom had the tumor located in the superomedial quadrant of the orbit.Computed tomography revealed a solitary ovoid lesion in 10(76.9%) patients and irregular lesion in 3(23.1%) patients.Magnetic resonance imaging results were as follows:On T1 weighted images,3(23.1%) patients had hypointense mixed signals,whereas 10(76.9%) patients showed isointense mixed signals;on T2 weighted images(T2 WI),3(23.1%),4 (30.8%),and 6(46.2%) patients exhibited hypointense mixed,isointense mixed,and hyperintense signals,respectively.Notably,12(92.3%) patients showed significant enhancement,whereas there were patchy slightly enhanced areas in the tumor.All patients were treated by surgery.IHC analysis demonstrated that the tumor cells were immunoreactive for CD34,CD99,STAT-6,and vimentin in all patients.The lesions showed Ki-67 positivity < 5% in 1(7.7) patient,5%-10% in 10(76.9%),and > 10% in 2(15.4%).Two(15.4%) patients exhibited tumor recurrence.CONCLUSION The clinical manifestations and radiologic characteristics of orbital SFT are diverse and not specific.Accurate diagnosis and treatment require detailed radiological and histopathological/IHC evaluation.

Solitary fibrous tumor of the renal pelvis:A case report

BACKGROUND Solitary fibrous tumor(SFT)is a rare mesenchymal neoplasm.SFT derived from the renal pelvis is an exceedingly rare entity.In this study,we report a case of renal pelvis SFT and review the relevant literature on this rare tumor.CASE SUMMARY A 76-year-old man was hospitalized due to right lumbar and abdominal pain.Abdominal computed tomography showed a hypervascular space-occupying renal lesion,sized 2.3 cm×1.8 cm.Based on the computed tomography findings,the patient was diagnosed with right renal pelvis tumor and underwent nephrectomy.Postoperative immunohistochemical results confirmed the diagnosis.As of the 3-year follow-up,there were no signs of recurrence,and the patient has recovered well.CONCLUSION We report a rare case of SFT derived from the renal pelvis and discuss the imaging and histopathological features that distinguish renal pelvis SFT from other renal pelvis tumors.

Mesentery solitary fibrous tumor with postoperative recurrence and sarcomatosis: A case report and review of literature

BACKGROUND Solitary fibrous tumors are rare neoplasms of mesenchymal origin. They are often of low malignant potential and rarely metastasize. They frequently arise from the pleura and can occur at any soft tissue site in the body. However, these tumors rarely develop in the mesentery, peritoneal cavity or peritoneum.CASE SUMMARY We report on a scarce case of solitary fibrous tumor of the rectal mesentery showing sarcomatosis about 4 years after previous tumor resection. This 69-yearold male had no clinical symptoms but was transferred to our hospital because of a suspected tumor recurrence from follow-up abdominal computed tomography.Tumor markers(CEA, CA 19-9 and CA 125) were within the normal range. Open laparotomy showed sarcomatosis, and pathology confirmed its mesenchymal origin and diagnosis as the solitary fibrous tumor. Our case may be the second recurrent mesentery solitary fibrous tumor reported to date, and the only one with progression to sarcomatosis. There has been no evidence of recurrence in follow-up at the 28 th mo after extensive intra-operative peritoneal lavage and cytoreductive surgery.CONCLUSION Although there are few risk factors of cancer recurrence in this patient, careful long-term followup after cytoreductive surgery is necessary.

Solitary Fibrous Tumor in Bladder:A Case Report

Solitary fibrous tumor(SFT) in bladder is extremely rare.In this study,we reported one case of bladder SFT and reviewed the only ten cases of the disease that had been reported so far.The patient suffered from residual urine sensation and urethral pain.Cystoscopy revealed a 7-cm protruding mass at the dome of the bladder,and bladder mucosa biopsy showed normal differentiation of the bladder mucosa with a small amount of inflammatory cells.Radical resection of the tumor was performed in this patient.Pathological examination found uniform,haphazardly arranged spindle cells,the majority of which were CD34-positive and Vimentin-positive and proved that the mass was a solitary fibrous tumor.Within a period of 9 months of follow-up,no reoccurrence was found.

Dumbbell-shaped solitary fibrous tumor in the parapharyngeal space:A case report

BACKGROUND Solitary fibrous tumors(SFTs)occurring in the parapharyngeal space are rare,and their final diagnosis depends on pathological and immunohistochemical analyses.Once the tumor is diagnosed,complete resection and regular postoperative follow-up are required.CASE SUMMARY A 40-year-old male patient with a right parotid gland mass discovered 8 years ago was admitted to hospital.The mass showed no tenderness or local skin redness.Imaging was carried out as the patient had stable vital signs and showed that the mass was a dumbbell-shaped tumor comprising a superficial tumor approximately 5 cm long and 3 cm wide in size that compressed the right parotid gland and a deep tumor located in the right parapharyngeal space approximately 4.5 cm long and 2.5 cm wide in size.Both tumors were connected in the middle.Prior to surgery,the tumors were considered to be parapharyngeal schwannomas.During surgical dissection,the tumors were found to be smooth and tough,without obvious adhesion to the surrounding tissues.The tumors were revealed to be a SFT following postoperative pathological analysis.CONCLUSION SFTs in the parapharyngeal space are rarely reported,and complete resection of such tumor is recommended.Adjuvant chemoradiotherapy is used in patients with extensive tumor invasion to lower the recurrence rate.Postoperative longterm follow-up is required.

Clinicopathological analysis of solitary fibrous tumor

Objective:The aim of this study was to investigate the clinicopathologic characteristics,diagnosis and differential diagnosis,molecular genetics,treatment and prognosis of solitary fibrous tumor(SFT).Methods:The clinicopathological manifestations were analyzed retrospectively in 22 patients with surgically confirmed SFT.Results:There were 12 male patients and 10 female patients,with the age range 33-67(mean 48.62) years.The SFTs originated from different from parts of the body,including 13 in the chest,2 in the lungs,3 in the abdomen,1 in the lumbosacral area,2 in the pelvis,and 1 in the left shoulder.There were 19 benign and 3 malignant tumors.Major clinical presentations were local masses and compression symptoms.Microscopy:the tumor was composed of areas of alternating hypercellularity and hypocellularity.The tumor cells were spindle to short-spindle shaped and arranged in fascicular or storiform pattern and hemangiopericytoma-like structure was presented.Immunohistochemically,Vimentin positive rate was 100%(22/22),Bcl-2 positive rate was 95.5%(21/22),CD99 positive rate was 86.4%(19/22),CD34 positive rate was 81.8(18/22),focally positive for P53,as well as negative CK,S100 and Desmin.Ki67 labelling index was 2%-30%.Conclusion:SFT is a rare tumor which may be found in various parts of human body.SFT mostly is a benign tumor,but a few could be malignant.Its diagnosis mainly rely on its morphologic features and immunohistochemical profiles.The major treatment is to completely resect it by operation and long-term clinical follow-up is necessary.