CT features of solitary fibrous tumour of the pleura: experience in 26 patients

Soft tissue solitary fibrous tumors of the musculoskeletal system: spectrum of MRI appearances and characteristic imaging features

OBJECTIVE

Solitary fibrous tumors (SFTs) uncommonly occur in the musculoskeletal system, with limited available data on their MRI appearance. This study was performed to assess the MRI features of SFTs in the musculoskeletal system (MSK-SFTs).

MATERIALS AND METHODS

Pre-treatment MRI in 39 patients with pathologically proven SFTs in the trunk or extremities was evaluated. Patient demographics, clinical management and follow-up, and lesion histology were reviewed. MRI features including lesion location, size, morphology, signal characteristics, vascularity, and relationship to major neurovascular structures were assessed.

RESULTS

MSK-SFTs most frequently occurred in the lower extremity (23/39 cases, 59%), deep to fascia (29/39, 74%), and intermuscular (22/29, 76%) in location. The majority of deep lesions were located along a major neurovascular bundle (20/29, 69%). Lesions had well-defined margins (39/39, 100%), multilobulated contours (27/39, 69%), and measured mean 6.9 ± 2.8 cm. The majority of lesions had slightly hyperintense T1 signal (34/39, 87%) and heterogenous intermediate-to-high T2/STIR signal (28/38, 74%). A "pseudo-cerebriform" internal architectural pattern on fluid-sensitive sequences, with internal lobulations and low signal bands/septations, was observed in 63% (24/38) of lesions. Lesions commonly demonstrated prominent intra-lesional (30/39, 75%) and peripheral juxta-lesional flow voids. Local invasion of surrounding structures was uncommon (3/39, 8%). Mitotically active lesions (p = 0.02) and lesions with tumor necrosis (p < 0.01) were larger in size. Tumor necrosis was associated with T1 heterogeneity (p = 0.04). Distant metastasis occurred in 10% (4/39) of patients, all in mitotically active lesions pre-operatively considered at least at intermediate risk of metastasis.

CONCLUSION

MSK-SFTs commonly present as well-defined, hypervascular masses deep to fascia along major neurovascular bundles, with heterogeneous slightly hyperintense T1 signal, intermediate-to-high T2/STIR signal, and prominent macroscopic flow voids.

Clinical and pathological analysis of solitary fibrous tumors with portal vein widening: A case report

RATIONALE

Solitary fibrous tumors (SFTs) are rare soft-tissue tumors characterized with spindle-cell, which occur more common in the chest and rarely seen in the abdomen. So far as we knew, SFTs accompanied with venopathy of portal vein has rarely been reported.

PATIENT CONCERNS

A 36-year-old male presented with left-sided abdominal mass and portal vein expansion on ultrasound.

DIAGNOSES

The post-operative histopathology confirmed the diagnosis of Solitary fibrous tumor.

INTERVENTIONS

Laparotomy was performed and the mass was completely removed.

OUTCOMES

Patients had no symptoms, recovered well without recurrence; the portal vein and splenic vein dilatation were alleviated and the symptoms of portal hypertension were relieved.

LESSONS

SFTs presents with few symptoms in the early stage of the disease. A rich arteriovenous shunt is beneficial to the diagnosis of SFTs by B-ultrasound and computed tomography (CT) examinations. However, the diagnosis of SFTs must depend on histopathology.

Primary omental malignant solitary fibrous tumour, an extremely rare malignancy: A case report and review of the literature

Primary omental malignant solitary fibrous tumour is an extremely rare neoplasm considering its tumour origin and pathologic characteristics. Solitary fibrous tumour (SFT) is a spindle cell neoplasm that was first described in 1931. SFT is diagnosed at immunohistochemical stain including CD34, bcl2, CD99 and STAT6. Though most of SFTs are benign in nature, 5-15% are malignant. The diagnostic criteria of malignant SFTs are high cellularity, high mitotic activity(>4/10HPF), pleomorphism, necrosis and haemorrhage. We present the case of a 57-year-old male patient diagnosed with primary omental malignant SFT. Neither tumour origin nor pathologic diagnosis were possible based on preoperative information. Nevertheless, tumour resection was performed successfully. Several SFT cases involving omentum without malignant potential have been reported. However, primary omental malignant SFTs are extremely rare with only 3 cases reported in the literature.

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.

CT diagnosis and differentiation of benign and malignant varieties of solitary fibrous tumor of the pleura

To investigate computed tomography (CT) characteristics of benign and malignant solitary fibrous tumors of the pleura (SFTPs).Preoperative CTs for 60 SFTP cases (49 benign and 11 malignant) with subsequently confirmed diagnoses were retrospectively analyzed.Tumor morphologies included mounded or mushroom umbrella-shape (19 cases, 31.7%), quasi-circular or oval-shape (30 cases, 50%), and growth resembling a casting mould (12 cases, 20%). Maximum tumor diameters were 1.1 to 18.9 cm (average: 6.4 ± 4.8 cm). Fifty-seven cases had clear boundaries, and 3 had partially coarse boundaries. Twenty-seven cases showed homogeneous density; 33, "geographic"-patterned inhomogeneous density; 6, calcifications; 12, intratumor blood vessels; and 3, thick nourishing peritumoral blood vessels. Pleural thickening (regular and irregular) was found adjacent to tumors in 4, compression of adjacent ribs with absorption and cortical sclerosis in 2, and location adjacent to ribs with bony destruction in 1. Four cases had a small amount of lung tissue enfolded along the boundary, 2 had multiple peritumoral pulmonary bullae, and 9 had small ipsilateral pleural effusions. Compared with benign and malignant SFTPs were larger (P < .001), had inhomogeneous density, and were more commonly associated with intratumor blood vessels and pleural effusions (P < .01).CT revealed characteristic patterns in SFTPs, including casting mould-like growth, rich blood supply, and "geographic"-patterned enhancement. In addition, larger tumor size, inhomogeneous intensities, abundant intratumor blood vessels, and pleural effusions were more common with malignancy. Lastly, multislice CT angiography can reveal feeding arteries and help guide surgical management.

A case of a "wandering" mobile solitary fibrous tumor occurring in the pancreas

A 73-year-old male with a complaint of abdominal discomfort was examined by abdominal ultrasonography and found to have a hypoechoic mass in the upper abdomen. On abdominal computed tomography (CT), there was a 5-cm, hypervascular mass between the stomach and aorta. Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) showed a homogeneous mass with hypointensity on T1-weighted images, accompanied by stenosis of the main pancreatic duct of the pancreatic head. On endoscopic ultrasonography, the mass was depicted as a round homogeneous, hypervascular mass attached to the pancreatic head. Surprisingly, the mass was located on the right side of the aorta on the second CT. Histological examination of the resected specimen showed that the lesion was composed of spindle cells with cord-like arrangement, the features of which were compatible with a mobile solitary fibrous tumor.

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.

Imaging findings of solitary fibrous tumor in the abdomen and pelvis

PURPOSE

The purpose of this study was to investigate the imaging characteristics of solitary fibrous tumor (SFT) in the abdomen and pelvis.

METHODS

Nine cases of SFT confirmed by surgery and pathology were retrospectively analyzed in terms of computed tomography (CT, eight cases) and magnetic resonance imaging (MRI, one case).

RESULTS

SFT were located in the retroperitoneum (4/9), abdominal cavity (1/9), pelvis (4/9). Eight cases were single (8/9) and one case (1/9) with three tumors. The average tumor size of 11 lesions was 9.7 cm (4.7-20 cm). Nine tumors were round or ovoid, and two lesions were irregular. The CT value of the plain scans ranged from 33 to 43 Hounsfield units (HU, mean 37.6 HU) in five cases. Arterial-phase CT found solid parts demonstrate avid enhancement (eight cases) and five of them presented with multiple circuitous vessels along the periphery with a CT value of 68-89 HU (mean 76.6 HU). In the venous and delayed phases, enhancement was strengthened progressively. The CT values at venous (eight cases) and delayed phases (five cases) were 108-115 and 112-123 HU respectively, with averages of 109.8 and 114.8 HU. Patch or nodular no-enhanced areas were observed in eight cases during the enhanced phases. One case showed isointensity on T1-weighted images and high signal intensity on T2-weighted images accompanied by linear or curvilinear hypointense lines. Intense enhancements along with linear no-enhancement areas are seen in the arterial and venous phases.

CONCLUSION

The possibility of SFT should be considered when a single or multiple masses with sharp border, inhomogeneous density or signal are detected, especially, with inhomogeneous intense enhancement in the arterial phase being maintained in the venous and delayed phases.

Primary intrathoracic malignant mesenchymal tumours: computed tomography features of a rare group of chest neoplasms

Objectives

To describe the computed tomography (CT) features in a case series of primary intrathoracic extracardiac malignant mesenchymal tumours (sarcomas).

Methods

A 5-year retrospective research was conducted, and 18 patients were selected. CT exams were reviewed by two chest radiologists, blinded to tumour pathological type, origin and grade. Lesions were described in relation to location, size, shape, margins, enhancement, presence of cavitation, calcifications, ground glass component, intratumoural enhanced vessels, pleural effusion, pleural tags, lymphangitis, chest wall/rib involvement and pathological lymph nodes.

Results

The readers described five pulmonary, six mediastinal and seven pleural/wall based lesions. Mean largest diameter was 103 mm. The most frequent shape was irregular (n = 12), most predominant margin was smooth (n = 12) and enhancement was mostly heterogeneous (n = 8). Intratumoural vessels and pleural effusion were seen in 11 patients. Pathological lymph nodes were present in four cases and calcifications in two cases.

Conclusions

Some frequent radiological features were described independently of tumour location and subtype. A sarcoma should be included as a major differential diagnosis when the radiologist faces an intrathoracic mass of large size (>70 mm) but with well defined smooth or lobulated margins, especially if presenting intratumoural vessels, associated pleural effusion but no significant lymphadenopathy.

Main messages

• Malignant mesenchymal tumours (sarcomas) are rare and can arise from any structure in the chest.

• Intrathoracic sarcomas show some frequent radiological features, independent of location and type.

• Some CT features may help the radiologist suspect for a sarcoma instead of other more common tumours.

Solitary fibrous tumor of the pleura: An analysis of forty patients

OBJECTIVE

To study the clinical characteristics, treatment and prognosis of patients with solitary fibrous tumor of the pleura (SFTP) in order to improve the diagnostic accuracy and treatment of SFTP.

METHODS

A retrospective analysis of clinical and imaging features, serum biochemical changes, pathological characteristics and treatment follow-up results was conducted for 40 SFTP patients from January 1998 to March 2010.

RESULTS

A chest CT diagnosis was conducted for 63.6% of the patients; the unenhanced and contrast-enhanced CT findings were significantly different among the cohort (P<0.01). Patients lacking a uniform MRI internal signal comprised 88.9% of the group, 66.7% showed T1 isointensity, 33.3% demonstrated T1 hypointensity, 44.4% showed T2 hypointensity and 44.4% had slight hypointensity. The follow-up time was between 2 and 116.9 months, with an average of 35 months; postoperative adjuvant therapy was not administered. Currently, all the studied patients are alive, with no metastasis or recurrence.

CONCLUSION

Chest CT is a valuable tool for diagnosis and surgical decisions, and the efficacy of MRI examination is comparable to chest CT. The majority of cases originated in the visceral pleural; for these, surgical resection is an effective treatment, and the prognosis is generally favorable.

Huge malignant solitary fibrous tumor of the pleura

INTRODUCTION

Solitary fibrous pleural tumors are rare mesenchymal tumors that can be mistaken for mesothelioma. A positive staining of vimentin, negative staining of cytoplasmic keratin, and expression of the CD34 antigen can confirm their diagnosis. These tumors should be surgically excised although they are benign because they have malignant potential and tendency for recurrence.

PATIENTS AND METHODS

We present here a 63-year-old patient who had an inconclusive biopsy of a huge right intrathoracic lesion. Further testing after radical surgical resection revealed a malignant solitary fibrous pleural tumor. Surgery was complicated with injury of the thoracic duct. Patient was re-operated upon for ligation of the thoracic duct. He is doing well with no recurrence after 18 months of follow-up.

CONCLUSION

In conclusion, definitive treatment for solitary fibrous tumor is radical surgical resection with close follow-up for the recurrences. Follow-up of this tumor is essential especially when it showed malignant features on pathological examination.

Malignant solitary fibrous tumor of retroperitoneum mimicking gastric submucosal tumor

Solitary fibrous tumors (SFTs) are an uncommon neoplasm characterized by the proliferation of spindle cells. The diagnostic criteria of malignant solitary fibrous tumors (MSFTs) include high cellularity, high mitotic activity (4>10 HPF), pleomorphism, hemorrhage and necrosis. This tumor frequently involves the pleura and MSFTs of retroperitoneum mimicking gastric submucosal tumor are very rare. We report a rare case of MSFT that presented as a gastric submucosal tumor. A gastroscopic examination showed a large bulging mucosa in the gastric body. Abdominal computed tomography revealed a well-defined heterogeneous enhancing mass between the left hepatic lobe and gastric body. Surgical resection was performed and histologic features were consistent with a MSFT.

Solitary fibrous tumors of the soft tissues: review of the imaging and clinical features with histopathologic correlation

OBJECTIVE

Solitary fibrous tumors are rare soft-tissue tumors of submesothelial origin with variable malignant potential. Most of these tumors originate within the thoracic cavity, but they can occur in a variety of sites, including the abdomen, pelvis, and soft tissues and muscles. The purpose of this study was to review the imaging findings with clinicopathologic correlation in 34 cases.

CONCLUSION

The finding of a large, solid, vascular tumor, particularly with prominent feeding vessels or a visible fatty component, should alert the radiologist to the possible diagnosis of solitary fibrous tumor. Percutaneous biopsy carries minimal risk and should be used for definitive diagnosis of these lesions, which in many cases are curable with surgery. The prognosis is good for patients with benign tumors but variable for those with malignant tumors.

Imaging of benign solitary fibrous tumor of the pleura: a pictorial essay

Solitary fibrous tumor of the pleura (SFTP) is a mesenchymal tumor that tends to involve the pleura, and is also described in other thoracic and extrathoracic sites. SFTP usually presents as a peripheral mass abutting the pleural surface, to which it is attached by a broad base or by a pedicle that allows it to be mobile. SFTPs exist in benign and malignant forms. A precise pre-operative diagnosis can be arrived at with a cutting-needle biopsy, although most cases are diagnosed with postoperative histology and immunohistochemical analysis. In this pictorial essay, we review a large series of cases, with emphasis on the radiographic appearance of these lesions and their findings from computed tomography, magnetic resonance imaging, ultrasonography and positron emission tomography.

Solitary fibrous tumor of the pancreas: imaging findings

We report here a case of a pathologically proven solitary fibrous tumor of the pancreas. A 54-year-old man was referred to our hospital for further evaluation of a pancreatic mass that was found incidentally. CT, MR imaging, and endoscopic ultrasonography showed a well-defined, enhancing mass with cystic portions of the pancreas body. MR cholangiopancreatography showed no pancreatic duct dilatation. A solitary fibrous tumor of the pancreas is a very rare lesion.