Delayed enhancement pattern in a localized fibrous tumor of the liver

Contrast-enhanced ultrasound (CEUS): one step forward in the identification of "high risk" solitary fibrotic tumors of the liver

BACKGROUND

Solitary fibrous tumors of the liver (SFTL) are rare neoplasms, whose identification and definition of malignant potential are challenging.

CASE PRESENTATION

A 62-year-old patient underwent conventional imaging and CEUS to characterize an indeterminate liver lesion after other imaging techniques were inconclusive. In fact, all diagnostic techniques concluded that it was a partially fibrotic lesion, while CEUS determined its extra-hepatocellular origin and malignant potential, initially hypothesized to be a cholangiocarcinoma. Due to the possible risk of seeding following a biopsy procedure, the patient was a candidate for surgery. Subsequently, histopathological examination revealed SFTL.

CONCLUSION

CEUS confidently characterized the malignancy and hypothesized the origin of the liver lesion, thus aiding in treatment planning.

Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

Solitary fibrous tumors (SFT) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. In the latest WHO 2020 Classification of Soft Tissue Tumors, extrameningeal SFT was listed as intermediate (rarely metastasizing) or malignant neoplasms. Due to the lack of characteristic clinical features, their diagnosis and treatment remain challenging. The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. Cytoplasmic CD34 positive staining is considerably characteristic for most SFTs; less frequently, factor XII, vimentin, bcl-2, and CD99 are present. A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. Radical resection is the mainstay of localized SFTs. In the case of unresectable disease, only radiotherapy or radio-chemotherapy may significantly ensure long-term local control of primary and metastatic lesions. To date, no practical guidelines have been published for the treatment of advanced or metastatic disease. Classical anthracycline-based chemotherapy is applicable. The latest studies suggest that antiangiogenic therapies should be considered after first-line treatment. Other drugs, such as imatinib, figitumumab, axitinib, and eribulin, are also being tested. Definitive radiotherapy appears to be a promising therapeutic modality. Since standards for the treatment of advanced and metastatic diseases are not available, further investigation of novel agents is necessary.

Imaging Features of Sclerosing Epithelioid Fibrosarcoma of the Pancreas: A Case Report

Background: Sclerosing epithelioid fibrosarcoma (SEF) is an extremely rare fibrosarcoma variant. There is no complete imaging data on SEF involving the pancreas. Herein we report the computed tomography (CT) and magnetic resonance imaging (MRI) data of a patient with SEF that primarily involved the pancreas.

Case Presentation: A 64-year-old man was found to have a solid mass in the tail of the pancreas on unenhanced CT. He had no constitutional symptoms. Contrast-enhanced abdominal CT and MRI were performed, and the results of the latter provided the diagnosis of a pancreatic neuroendocrine tumor. Laparoscopic distal pancreatectomy and splenectomy were performed. Anatomopathological examination and immunohistochemistry confirmed that the tumor was a SEF of the pancreas. The patient had no signs of recurrence or metastasis during a 12-months follow-up.

Conclusion: We report an extremely rare case of SEF in the pancreas and its characterization with CT and MRI.

Ex situ hepatectomy and liver autotransplantation for a treating giant solitary fibrous tumor: A case report

A solitary fibrous tumor (SFT) is a rare mesenchymal tumor. Ex situ hepatectomy and liver autotransplantation are novel methods for the treatment of complicated liver tumors, for example, those involving vascular structures, including the inferior vena cava, which are unresectable by conventional approaches. The present study describes a rare case of a massive hepatic SFT in a 32-year-old female who underwent ex situ hepatectomy and liver autotransplantation to achieve a radical resection. The surgery was without complications. Post-operative histopathological and immunohistochemical examinations revealed an SFT of the liver. The patient was discharged 29 days after the surgery with fully recovered liver function. The routine check-up 3 months after surgery indicated normal liver function and no evidence of recurrence. Additionally, an exhaustive review of available literature was performed to provide a complete overview of the current status of SFTs. In summary, the present study found that ex situ hepatectomy and liver autotransplantation are suitable surgical techniques for treating a giant SFT, as well as other liver neoplasms that are considered unresectable by conventional surgery.

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.

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.

Solitary Fibrous Tumor of the Liver: a Review of the Current Knowledge and Report of a New Case

INTRODUCTION

Solitary fibrous tumors of the liver (SFTL) are uncommon tumors; to the present day, less than 50 cases has been reported in the English scientific literature, most of which behaved as benign tumors. The present article reports a new case of SFTL and has the main purpose of updating the current knowledge of SFTL because due to its rarity, its clinical presentation, study, treatment, and prognosis are not well known. The clinical presentation, radiologic study, surgical treatment, immunohistochemical study, and prognosis are updated and comprehensively discussed.

METHODS

Using the common search engines, a search of the English literature was conducted for "Solitary Fibrous Tumor of The Liver," and the relevant articles were retrieved, reviewed, and analyzed.

RESULTS

All published articles reported anecdotal SFTLs, or SFTLs were included in large series analyzing solitary fibrous tumors on different sites.

CONCLUSION

The SFTL is an uncommon neoplasm. The clinical presentation is habitually indolent and its behavior is uncertain. In some cases, the SFTL acts as an aggressive sarcoma with poor prognosis. Currently, only surgery offers a therapeutic opportunity for these patients. Due to the lack of current knowledge of long-term behavior of supposedly benign SFTLs and to the lack of specific therapies, methodical long-term follow-up is essential to ensure the survival of patients treated for SFTL.

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.

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.

METHODS: Fifteen patients with pathologically confirmed SFTs in the abdomen and pelvis were retrospectively studied with imaging techniques by two radiologists in consensus. Patients underwent unenhanced and contrast-enhanced imaging, as follows: 3 with computed tomography (CT) and magnetic resonance imaging (MRI) examination, 8 with CT examination only, and 4 with MRI examination only. Image characteristics such as size, shape, margin, attenuation or intensity, and pattern of enhancement were analyzed and correlated with the microscopic findings identified from surgical specimens. In addition, patient demographics, presentation, and outcomes were recorded.

RESULTS: Of the 15 patients evaluated, local symptoms related to the mass were found in 11 cases at admission. The size of the mass ranged from 3.4 to 25.1 cm (mean, 11.5 cm). Nine cases were round or oval, 6 were lobulated, and 10 displaced adjacent organs. Unenhanced CT revealed a heterogeneous isodense mass in 7 cases, homogeneous isodense mass in 3 cases, and punctuated calcification in one case. On MRI, most of the lesions (6/7) were heterogeneous isointense and heterogeneous hyperintense on T1-weighted images and T2-weighted images, respectively. All tumors showed moderate to marked enhancement. Heterogeneous enhancement was revealed in 11 lesions, and 7 of these had cysts, necrosis, or hemorrhage. Early nonuniform enhancement with a radial area that proved to be a fibrous component was observed in 4 lesions, which showed progressive enhancement in the venous and delayed phase. No statistical difference in the imaging findings was observed between the histologically benign and malignant lesions. Three patients had local recurrence or metastasis at follow-up.

CONCLUSION: Abdominal and pelvic SFTs commonly appeared as large, solid, well-defined, hypervascular masses with variable degrees of necrosis or cystic change that often displaced adjacent structures.

Solitary fibrous tumors of the soft tissues: imaging features with histopathologic correlations

Purpose

To describe the imaging features of soft tissue solitary fibrous tumors, with histopathological correlations and clinical outcome.

Material and methods

Twenty-seven patients with histologically proven SFTs were retrospectively evaluated. Imaging studies included six radiographs, five U/S studies, eighteen CT scans, fourteen MRI exams, and one angiography.

Results

On CT scans, two lesions were isodense and five were mildly hypodense compared to muscle while 11 lesions appeared heterogeneous-mixed of iso and hypodense areas. Heterogeneous enhancement was depicted in 13 lesions and four lesions enhanced homogeneously. Six lesions were partially calcified. On T1W MR images, seven lesions were isointense and one was slightly hyperintense relative to adjacent muscles while five lesions appeared heterogeneous-mixed of iso and hypointense areas. T2W images showed high SI in two cases and heterogeneous-mixed in seven cases. Enhancement was heterogeneous in six and homogeneous in four lesions. Patchy unenhanced areas (on CT and T1W MR images) along with patchy areas of low to markedly high SI on T2W images were depicted in 19 lesions. The enhanced portions correlated to areas of increased vascularity and cellularity. The four clinically more aggressive lesions could not be predicted on imaging.

Conclusion

Typical soft tissue SFTs are deep masses made of isodense and isointense areas relative to adjacent muscles mixed with hypodense and hypointense areas on unenhanced CT and MR T1W respectively. Variable enhancement patterns and mixed to high signal intensities on MRT2W are attributed to tumor’s cellularity, vascularity, collagen distribution and/or degeneration. Heterogeneity of SFTs affects imaging features on MRI and CT modalities. The biological behavior of soft tissue SFTs can not be predicted based solely either on histopathologic or imaging evaluation.

Somatic and visceral solitary fibrous tumors in the abdomen and pelvis: cross-sectional imaging spectrum

Solitary fibrous tumors (SFTs) are a unique group of mesenchymal neoplasms of fibroblastic or myofibroblastic origin. These tumors were originally described as "benign fibrous mesotheliomas" of the pleural cavity and were erroneously thought to be confined to the serosal surfaces (due to a putative mesothelial or submesothelial origin). It is now established that SFTs are ubiquitous neoplasms with both pleural and extrapleural distribution. Extrapleural SFTs commonly occur in middle-aged adults and manifest as asymptomatic, slow-growing, large tumors. Fewer than 5% of patients with SFTs present with symptomatic hypoglycemia. SFTs are histopathologically diverse with a variable admixture of fibroblasts or myofibroblasts, numerous thin-walled vessels, and dense fibrosis. Tumors previously categorized as hemangiopericytomas are now considered cellular variants of SFTs. At imaging, SFTs demonstrate remarkable heterogeneity, with variable degrees of enhancement, necrosis, or hemorrhage. Although most extrapleural SFTs have a benign clinical course, 10%-15% of these tumors demonstrate aggressive behavior in the form of recurrence or malignancy.

Tumors of the liver and intrahepatic bile ducts: radiologic-pathologic correlation

Primary tumors of the liver can be classified pathologically based on their cell of origin into epithelial tumors, arising from hepatocytes or biliary epithelium, and nonepithelial tumors, including mesenchymal tumors and lymphoma. Characteristic findings on MR imaging can be seen in many cases. This article reviews the MR imaging appearance of these tumors with pathologic correlation.

Solitary fibrous tumor of the genitourinary tract

OBJECTIVE

The purpose of this article is to describe the imaging features of solitary fibrous tumors involving the kidney, bladder, adrenal gland, retroperitoneum, or pelvis and other rare locations.

CONCLUSION

Although clear radiologic differentiation of solitary fibrous tumors from malignancy is not possible, we suggest that familiarity with the manifestations of solitary fibrous tumors can help to avoid unnecessary radical surgery before histopathologic proof of malignancy is obtained.

Imaging findings of calcifying fibrous tumour of the liver

Calcifying fibrous tumour (CFT) is a recently recognised rare benign lesion characterised by dense hyalinised collagenous tissue, psammomatous or dystrophic calcifications and a lymphoplasmacytic infiltrate. The usual locations of the lesion are the soft tissues of the extremities, but rarely it occurs in the abdomen. Recently, we experienced a case of CFT found in the liver of a 29-year-old woman. Here, we describe the characteristic radiological and histopathological findings, along with a review of the relevant literature.

[Solitary fibrous tumor: imaging findings and review of the literature]

Solitary fibrous tumors of the liver are uncommon. First reported in the pleura, this tumor has also been reported in other locations both within and outside the thorax. It rarely affects the liver parenchyma. The clinical, radiological, and immunohistochemical findings characterize the lesion and distinguish it from other tumors with a similar appearance. We present the case of a solitary fibrous tumor in the liver; we place special emphasis on the findings at ultrasonography, computed tomography, and magnetic resonance imaging. Finally, we review the literature.

Computed tomography and magnetic resonance imaging findings of solitary fibrous tumors in the pelvis: correlation with histopathological findings

OBJECTIVE

We aimed to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of pelvic solitary fibrous tumors (SFTs) and to improve the diagnostic efficacy for such tumors.

METHODS

Six cases of pelvic SFTs confirmed by histopathology were analyzed retrospectively. Of the 6 patients, 4 had undergone CT scanning, and 2 had undergone magnetic resonance imaging. All the patients had undergone unenhanced and contrast-enhanced examinations, and 2 had also undergone dynamic CT enhancement examination. Image characteristics such as shape, size, number, edge, attenuation or intensity for each lesion before and after contrast enhancement were analyzed and compared with the pathomorphology of the tumors.

RESULTS

All the 6 cases showed oval or rounded and well-defined masses. Unenhanced CT images showed heterogeneous masses with patchy, necrotic foci in 3 cases and homogeneous mass in 1 case. None of the tumors showed calcification. Contrast-enhanced CT images showed marked, heterogeneous enhancement in the first and second cases. Dynamic enhancement scan demonstrated mild homogeneous enhancement in the third case and mild prolonged, delayed enhancement and washout in the fourth case. T1-weighted MR images showed heterogeneous mild hypointense lesion with linear hyperintensity in 1 case, and homogeneous isointensity in the other. T2-weighted images showed heterogeneous mixed intensity in 1 case and mostly hyperintensive lesion with hypointense foci in another case. A case showed marked heterogeneous enhancement and another showed marked homogeneous enhancement on contrast-enhanced T1-weighted images.

CONCLUSION

Radiological findings of pelvic SFTs are variable and nonspecific. However, a well-defined, ovoid or rounded mass with hypointense on MR T2-weighted images and variable enhancement on CT and MR images may suggest the diagnosis of SFTs. Pelvic SFTs should be included in the differential diagnosis of regional tumors.

Solitary fibrous tumor (SFT) of the pelvis

Solitary fibrous tumors (SFTs) are well recognized in the pleura, but their occurrence at other sites has only become appreciated in recent years, as a consequence of which extrapleural examples often go unrecognized and misdiagnosed. Because of their rarity, overall experience concerning this tumor has not been significant and reports detailing radiological findings are few. We herein report an unusual case of a large retroperitoneal pelvic SFT with features of high vascularity negating successful surgical resection.