Sclerosing epithelioid fibrosarcoma of bone with hybrid features: clinicopathologic, radiologic, and molecular analysis of three cases.

Sclerosing epithelioid fibrosarcoma (SEF) occurring as a primary bone tumor is exceptionally uncommon. Even more rare are cases of SEF that show morphologic overlap with low-grade fibromyxoid sarcoma (LGFMS). Such hybrid lesions arising within the bone have only rarely been reported in the literature. Due to their variegated histomorphology and non-specific radiologic features, these tumors may pose diagnostic difficulties. Herein we describe three molecularly confirmed primary bone cases of sclerosing epithelioid fibrosarcoma that demonstrated prominent areas showing the features of LGFMS and with areas resembling so-called hyalinizing spindle cell tumor with giant rosettes (HSCTGR). Two patients were female and one was male aged 26, 47, and 16, respectively. The tumors occurred in the femoral head, clavicle, and temporal bone. Imaging studies demonstrated relatively well-circumscribed radiolucent bone lesions with enhancement on MRI. Cortical breakthrough and soft tissue extension were present in one case. Histologically the tumors all demonstrated hyalinized areas with SEF-like morphology as well as spindled and myxoid areas with LGFMS-like morphology. Two cases demonstrated focal areas with rosette-like architecture as seen in HSCTGR. The tumors were all positive for MUC4 by immunohistochemistry and cytogenetics, fluorescence in-situ hybridization, and next-generation sequencing studies identified EWSR1 gene rearrangements confirming the diagnosis in all three cases.Hybrid SEF is exceedingly rare as a primary bone tumor and can be difficult to distinguish from other low-grade spindled and epithelioid lesions of bone. MUC4 positivity and identification of underlying EWSR1 gene rearrangements help support this diagnosis and exclude other tumor types.

Ameloblastic fibrosarcoma of the maxilla arising in an old woman, a rare case report and literature review.

BACKGROUND: Ameloblastic fibrosarcoma (AFS) is a rare malignant odontogenic tumor, commonly occurring in young adults and typically affecting the mandibular region. We report an exceptionally rare and highly atypical case of AFS in an elderly female patient originating from the maxillary bone. CASE PRESENTATION: A 66-year-old woman was admitted with a two-week history of a lump in her left upper molar. CT scans suggested a cyst in the maxillary bone. An incisional biopsy revealed a spindle cell neoplasm. MRI showed abnormalities in the left maxilla, indicating a possible tumorous lesion. The patient underwent a subtotal maxillectomy, wide tumor excision, intraoral epithelial flap transplantation, and dental extraction. Histology identified atypical tumor cells with visible mitotic figures. Immunohistochemistry showed negative for PCK and CD34 expression, but positive for Vimentin and SMA expression. The Ki-67 proliferation index ranged from 30 to 50%. These findings suggested a potentially malignant soft tissue tumor in the left maxilla, leaning towards a diagnosis of AFS. The patient received postoperative radiotherapy. There was no recurrence during the six-month follow-up. CONCLUSION: Based on repeated pathological evidence, we report a rare case of an elderly female with AFS originating from the maxillary bone. Surgery and postoperative radiotherapy resulted in a favorable outcome.

Fibroblastic and Myofibroblastic Soft-Tissue Tumors: Imaging Spectrum and Radiologic-Pathologic Correlation.

Fibroblastic and myofibroblastic tumors are a variable group of neoplasms ranging from benign to malignant. These lesions may affect patients of any age group but are more frequently encountered in the pediatric population. Patient clinical presentation depends on the location, growth pattern, adjacent soft-tissue involvement, and pathologic behavior of these neoplasms. In the 2020 update to the World Health Organization (WHO) classification system, these tumors are classified on the basis of their distinct biologic behavior, histomorphologic characteristics, and molecular profiles into four tumor categories: (a) benign (eg, fibrous hamartoma of infancy, nodular fasciitis, proliferative fasciitis, fibroma of the tendon sheath, calcifying aponeurotic fibroma); (b) intermediate, locally aggressive (eg, desmoid fibromatosis); (c) intermediate, rarely metastasizing (eg, dermatofibrosarcoma protuberans, myxoinflammatory fibroblastic sarcoma, low-grade myofibroblastic sarcoma, infantile fibrosarcoma); and (d) malignant (eg, sclerosing epithelioid fibrosarcomas; low-grade fibromyxoid sarcoma; myxofibrosarcoma; fibrosarcoma, not otherwise specified). Detection of various components of solid tumors at imaging can help in prediction of the presence of corresponding histopathologic variations, thus influencing diagnosis, prognosis, and treatment planning. For example, lesions with a greater myxoid matrix or necrotic components tend to show higher signal intensity on T2-weighted MR images, whereas lesions with hypercellularity and dense internal collagen content display low signal intensity. In addition, understanding the radiologic-pathologic correlation of soft-tissue tumors can help to increase the accuracy of percutaneous biopsy and allow unnecessary interventions to be avoided. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Infantile fibrosarcoma of the perineum with dorsal metastasis in a neonate: a case report original.

BACKGROUND: Infantile fibrosarcoma is a rare pediatric soft tissue tumor and usually appears in children before one year of age. Distal extremities constitute the most frequently affected locations, and other tissues such as the trunk, head and neck, gut, sacrococcygeal region, and viscera are uncommon sites. CASE PRESENTATION: We describe a rare case of infantile fibrosarcoma arising from the perineum. First, a cystic mass was detected using prenatal ultrasonography, and then an echo was changed in serial ultrasound examinations. A solid cystic lesion was found at term; a hypoechoic lesion occurred in the back. The tumor became so large that massive bleeding occurred, which then underwent surgical resection. Pathological examination confirmed infantile fibrosarcoma. CONCLUSION: Our report demonstrates not all ultrasonographic findings in cases of infantile fibrosarcoma exhibit a solid mass during the initial examination - an early-stage lesion may reveal a cystic echo. Infantile fibrosarcoma has a good prognosis and surgery constitute the main treatment, with adjuvant chemotherapy being received if necessary.

Needle tract seeding of a sclerosing epithelioid fibrosarcoma in a biopsy tract: a case report.

BACKGROUND: A sclerosing epithelioid fibrosarcoma (SEF) is an uncommon tumor of the deep soft tissue. An SEF has been described as a low-grade tumor with high local recurrence and metastatic rates. Generally, in bone and soft tissue tumors, a resection of the biopsy route is recommended; however, there is limited evidence with respect to the dissemination of the tumor tissue during a needle biopsy. CASE PRESENTATION: A mass in the right pelvic cavity, with no symptoms, was observed in a 45-year-old woman during a gynecological examination. Computed tomography (CT) revealed a multilocular mass with calcification in the pelvic cavity. The magnetic resonance imaging (MRI) showed an iso-signal intensity on T1 weighted images and hypo- and iso-signal intensity on T2 weighted images. The CT-guided core needle biopsy was performed using a dorsal approach, and the biopsy diagnosis was a low-grade spindle cell tumor. The tumor was excised using an anterior approach. The tumor tissue comprised spindle cells and epithelioid cells with irregular nuclei, and the immunohistological analysis was positive for vimentin and epithelial membrane antigen, which was consistent with a diagnosis of sclerosing epithelioid fibrosarcoma. Five years after the surgery, the MRI showed a tumor recurrence in the subcutaneous tissue of the right buttock, which was consistent with the needle biopsy tract. The patient underwent a tumor excision, and the resected tumor was similar to the primary tumor. CONCLUSIONS: The recurrent tumor was excised with a surgical margin, and the tumor specimen had the histological features of a sclerosing epithelioid fibrosarcoma. It was difficult to investigate the association of the core needle biopsy with the tumor recurrence because the approach of the biopsy tract is usually same as that used in a tumor excision. However, the present case indicated the tumor may recur in the biopsy tract of a soft tissue sarcoma. Surgeons should be aware of the possibility of disseminating tumor tissues in a needle biopsy.

Sclerosing epithelioid fibrosarcoma of the lumbar spine: a case report and review of the literature.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft tissue tumour subtype, and those arising from the spine are even rarer. To the best of our knowledge, only 3 cases with the spine as the primary site of SEF have been previously reported. We report a 61-year-old female who presented with backache and bilateral leg numbness for 3 years, worsened over the last three months. Pathological fracture of the L1 vertebra was detected, and soft tissue density in the spinal canal and left vertebral body margin was also seen on contrast CT. She underwent tumour resection via a posterior approach, decompression, bone grafting, fusion, and internal fixation. Histology confirmed the diagnosis of SEF.

Long term follow-up of congenital infantile fibrosarcoma of the orbital region.

We present the long-term follow-up of a case of periorbital congenital infantile fibrosarcoma (CIFS) treated with chemotherapy and surgery. The tumor was detected on a routine prenatal ultrasound at 30 weeks of gestation and diagnosed via an orbital biopsy day 9 postnatal age. The patient underwent chemotherapy and surgical debulking within the first 3 months of life and has maintained complete tumor remission for 7 years. The case highlights that early recognition and prompt treatment of periorbital CIFS can lead to complete long-term remission of this uncommon malignancy.

Imaging characteristics of infantile fibrosarcoma.

AIM: To highlight the imaging findings in a case series of histologically confirmed infantile fibrosarcoma (IF) and identify any features specific to this entity. MATERIALS AND METHODS: Retrospective identification was undertaken of patients with histologically confirmed IF from the electronic patient databases of two institutions between 1 January 2010 and 1 May 2021. Available pre-treatment imaging, histopathological reports, and clinical records were reviewed. RESULTS: Eighteen patients with IF met the inclusion criteria. There were 10 male and eight female patients with a mean age at presentation of 3 weeks. All patients had the t (12; 15) chromosomal translocation. Eleven (61%) tumours were located in the extremities, three were in the craniofacial region, two were intrathoracic, one abdominal and one paraspinal. A single patient had extensive metastases. The tumours were generally isointense to skeletal muscle on T1-weighted sequences and hyperintense on T2 with heterogeneous enhancement and high cellularity seen as diffusion restriction. Fifteen of the 18 lesions were evaluated on ultrasound and appeared as heterogeneous, hypervascular solid or mixed solid/cystic masses, mimicking benign vascular lesions in two cases. CONCLUSION: The present two-centre, retrospective study of the largest case series described thus far demonstrates that IF is always highly cellular on magnetic resonance imaging but has no other specific imaging features. It should be considered in the differential diagnosis of any enlarging soft-tissue, solid mass arising in the limbs or neck at birth or in infancy.

Ultrasound of myxofibrosarcoma.

The ultrasound appearance of myxofibrosarcoma is highly variable corresponding to its variable and at times heterogeneous histopathologic appearance. Myxofibrosarcomas may mimic a benign process and the infiltrative tumor margins may be difficult to precisely delineate on ultrasound imaging. These tumor characteristics pose a diagnostic challenge on ultrasound evaluation. The radiologist should be aware of the variable morphologic presentation and infiltrative nature of myxofibrosarcoma and the limitations of ultrasound in the initial diagnosis, biopsy guidance, and post-surgical follow-up of this tumor.

The clinicoradiological features and surgical outcomes of primary intracranial fibrosarcoma: a single-institute experience with a systematic review.

Primary intracranial fibrosarcoma (PIF) was a rare tumor with a high relapse rate and dismal survival rate. This study aimed to delineate the clinical characteristics of primary intracranial fibrosarcoma (PIF) and the risk factors for outcomes. We reviewed 15 PIF patients, who underwent surgical treatment at our institution from January 2009 to December 2018. Meanwhile, 36 cases from the prior literature between November 1962 and December 2019 were also retrieved and pooled to identify the risk factors. In our cohort, while cystic component (46.7%), perilesional edema (83.3%), and vascular flow void (66.7%) were commonly observed, no patient was accurately diagnosed. The 2-year relapse-free survival (RFS) and overall survival (OS) were 12.2% and 30.2%, respectively. Based on the pooled data, tumor size (p = 0.006), Ki-67 index (p = 0.004), and radiotherapy dose (p = 0.029) were prognostic factors for RFS in univariate analysis. In the univariate analysis, tumor size (p = 0.002), NGTR (p = 0.049), and high Ki-67 index (p = 0.019) were significant predictors for OS; and further multivariate analysis (n = 18) showed that large tumor size (≥ 5 cm; HR 14.613, p = 0.022) and high Ki-67 index (≥ 30%; HR 5.879, p = 0.020) were the independent risk factors for OS. Due to the rarity and nonspecific clinicoradiological features, the correct diagnosis of PIF before surgery was challenging. The outcomes of PIF were poor, and GTR plus radiotherapy (at least 60 Gy) might benefit to the outcomes and were recommended. Future study with a large cohort was needed to verify our findings.

Intramuscular Grade 1 fibrosarcoma: Magnetic resonance imaging findings in 2 dogs.

Two adult neutered male dogs were presented for evaluation of firm, painless masses arising within muscle: an 8-year-old German wirehaired pointer dog with an accessory tricipital growth, and a 3-year-old German shepherd dog with a gracilis muscle growth. Magnetic resonance imaging (MRI) characteristics suggested malignant behavior, with a central fluid-like portion with a hyperenhancing lining, a nidus of disorganized tissue, and an extensive reactive zone, whereas histopathology was consistent with low-grade fibrosarcoma. This report describes histologically low-grade, yet biologically high-grade intramuscular fibrosarcoma, in which MRI provided detailed information on tumor behavior and assisted with biopsy and surgical planning.

Fibrosarcome intramusculaire de Grade 1 chez deux chiens : Imagerie par résonance magnétique. Ce rapport de cas décrit des fibrosarcomes intramusculaires de bas grade histologique mais au comportement biologique de haut grade ainsi que leur imagerie par résonance magnétique (IRM) chez deux chiens mâles castrés évalués pour des masses musculaires fermes et indolores : un Braque Allemand de 8 ans avec une masse originant de la branche accessoire du muscle triceps, et un Berger Allemand de 3 ans avec une masse au muscle gracile. L'IRM a révélé une zone centrale liquide bordée d'une mince couche au rehaussement marqué, adjacent à un foyer de tissu désorganisé, entourés par une zone réactive étendue. L'histopathologie des lésions révèle un fibrosarcome et malgré la présence d'anomalies histologiques de bas grade, l'infiltration des muscles adjacents est documentée par microscopie et les caractéristiques d'imagerie sont celles associées chez l'humain avec un comportement malin.(Traduit par les auteurs).

Imaging of fetal tumors and other dysplastic lesions: A review with emphasis on MR imaging.

Fetal tumors and other dysplastic masses are relatively rare. They are usually the result of failure of differentiation and maturation during embryonic or fetal life; dysplastic lesions may be the consequence of an obstruction sequence. In this review, we present the most commonly encountered tumors and masses seen during fetal life. Imaging characteristics, tumoral organ of origin, and its effect on the surrounding organs and overall fetal hemodynamics are descriptors that must be relayed to the fetal surgeon and maternal fetal medicine expert, in order to institute most accurate parental counseling and appropriate perinatal treatment plan.

Clinical Characteristics and Surgical Features of Intracranial Fibrosarcoma.

BACKGROUND: Intracranial fibrosarcoma is an extremely rare neoplasm in the central nervous system. Insofar there were only sporadic case reports describing its features. The purpose of this study is to review the clinical and surgical features of cases who were treated in our department. METHOD: The authors retrospectively reviewed and detailed the clinical and surgical data obtained from 5 patients with fibrosarcoma who underwent treatment at our institute between January 2009 and January 2019. RESULTS: There were 3 males and 2 females including 2 juvenile and 3 senior patients. The most frequent sign was intermittent pain and vomiting. The location of the tumor included middle fossa, thalamus and midbrain, sellar and suprasellar region and right parietal-occipital lobe. Surgical observation demonstrated the consistency of the tumor was tenacious with abundant blood supply. Gross total resection was achieved in 2 cases. Pathological analysis showed spindle cells in a herringbone form with positive Vimentin staining in all 5 cases, with the absence of GFAP or S-100. All 5 patients were deceased eventually after a varied period of time after the first surgery. CONCLUSION: Intracranial fibrosarcoma was a highly malignant entity presented in the central nervous system. Surgery still remains the first-line treatment followed by radiotherapy, however, the prognostic outcome was very poor. Future studies should be more focused on accumulation of the relevant information on this disease thus hopefully in assisting to developing more optimized treatment.

Myxofibrosarcoma, in the calf of a middle aged female: a case report.

Myxofibrosarcoma belongs to the group of sarcoma tumours, which represent only 1% of the adult tumours worldwide. It is one of the rare, aggressive connective tissue neoplasm of malignant fibrocytes in a myxoid matrix, and mostly occurs in people in their 60s to 80s. Like many other tumours of connective tissue, it reveals high recurrence rates, but rarely metastasise. We present a case of a 50-year-old female who had a large, soft tissue sarcoma over the left leg. Wide surgical excision was done due to its increased size and aggressive clinical behaviour, so as to increase the patient's comfort. On histopathology, the tumour was diagnosed as high-grade myxofibrosarcoma with no evidence of metastasis.

Radiomic features from MRI distinguish myxomas from myxofibrosarcomas.

BACKGROUND: Myxoid tumors pose diagnostic challenges for radiologists and pathologists. All myxoid tumors can be differentiated from each other using fluorescent in-situ hybridization (FISH) or immunohistochemical markers, except for myxomas and myxofibrosarcomas. Myxomas and myxofibrosarcomas are rare tumors. Myxomas are benign and histologically bland, whereas myxofibrosarcomas are malignant and histologically heterogenous. Because of the histological heterogeneity, low grade myxofibrosarcomas may be mistaken for myxomas on core needle biopsies. We evaluated the performance of T1-weighted signal intensity (T1SI), tumor volume, and radiomic features extracted from magnetic resonance imaging (MRI) to differentiate myxomas from myxofibrosarcomas. METHODS: The MRIs of 56 patients (29 with myxomas, 27 with myxofibrosarcomas) were analyzed. We extracted 89 radiomic features. Random forests based classifiers using the T1SI, volume features, and radiomic features were used to differentiate myxomas from myxofibrosarcomas. The classifiers were validated using a leave-one-out cross-validation. The performances of the classifiers were then compared. RESULTS: Myxomas had lower normalized T1SI than myxofibrosaromas (p = 0.006) and the AUC using the T1SI was 0.713. However, the classification model using radiomic features had an AUC of 0.885 (accuracy = 0.839, sensitivity = 0.852, specificity = 0.828), and outperformed the classification models using T1SI (AUC = 0.713) and tumor volume (AUC = 0.838). The classification model using radiomic features was significantly better than the classifier using T1SI values (p = 0.039). CONCLUSIONS: Myxofibrosarcomas are on average higher in T1-weighted signal intensity than myxomas. Myxofibrosarcomas are larger and have shape differences compared to myxomas. Radiomic features performed best for differentiating myxomas from myxofibrosarcomas compared to T1-weighted signal intensity and tumor volume features.

Overview of the clinical and imaging features of the most common non-rhabdomyosarcoma soft-tissue sarcomas.

Non-rhabdomyosarcoma soft-tissue sarcoma (NRSTS) refers to a widely heterogeneous group of extraskeletal mesenchymal neoplasms accounting for approximately 4% of all childhood cancers. This article summarizes the clinical and imaging features of these rare tumors and describes in detail the three most common histological types of NRSTSs encountered in children - synovial sarcoma, malignant peripheral nerve sheath tumor and infantile fibrosarcoma. The author discusses the role of non-cross-sectional and cross-sectional imaging.

Upper extremity myxofibrosarcoma mimicking an erosive inflammatory arthritis: a case report.

Myxofibrosarcoma is a malignant fibroblastic soft tissue neoplasm containing a variable amount of myxoid stroma that commonly presents as a slow-growing mass in elderly patients. The neoplasm may be superficial or deep to the muscle fascia and characteristically has an infiltrative growth pattern with a dominant or multinodular mass. We describe an unusual case of high-grade myxofibrosarcoma of the wrist and forearm that infiltrated the muscles, tendons, and wrist joint, causing bone erosions. The tumor was mistakenly diagnosed as synovitis and a chronic, erosive, inflammatory process. The diffuse nature, absence of a dominant mass, and radiographic appearance complicated the diagnosis. Although neoplasms of the synovial spaces are rare, this case demonstrates that tumors with a highly infiltrative growth pattern can mimic inflammatory synovitis and that neoplasms should be considered in the differential diagnosis when clinical and laboratory features are discordant with the imaging appearance.

Evaluation of fluorescence-guided surgery agents in a murine model of soft tissue fibrosarcoma.

BACKGROUND AND OBJECTIVES: Soft tissue sarcomas (STS) are mesenchymal malignancies. Treatment mainstay is surgical resection with negative margins ± adjuvant treatment. Fluorescence-guided surgical (FGS) resection can delineate intraoperative margins; FGS has improved oncologic outcomes in other malignancies. This novel strategy may minimize resection-associated morbidity while improving local tumor control. METHODS: We evaluate the tumor-targeting specificity and utility of fluorescence-imaging agents to provide disease-specific contrast. Mice with HT1080 fibrosarcoma tumors received one of five probes: cetuximab-IRDye800CW (anti-EGFR), DC101-IRDye800CW (anti-VEGFR-2), IgG-IRDye800CW, the cathepsin-activated probe Prosense750EX, or the small molecule probe IntegriSense750. Tumors were imaged daily using open- and closed-field fluorescence imaging systems. Tumor-to-background ratios (TBR) were evaluated. On peak TBR days, probe sensitivity was evaluated. Tumors were stained and imaged microscopically. RESULTS: At peak, closed-field imaging TBR of cetuximab-IRDye800CW (16.8) was significantly greater (P < 0.0001) than Integrisense750 (7.0), Prosense750EX (5.8), and DC101-IRDye800CW (3.7). All agents successfully localized as little as 1.0 mg of tumor tissue in the post-resection bed; cetuximab-IRDye800CW generated the greatest contrast (2.5). Cetuximab-IRDye800CW revealed strong tumor affinity microscopically; tumor fluorescence intensity was significantly greater (P < 0.0004) than 0.2 mm away from tumor border. CONCLUSION: This study demonstrates cetuximab-IRDye800CW superiority. FGS has the potential to improve post-resection morbidity and mortality by improving disease detection.

Left atrial appendage myxofibrosarcoma: A rare masquerader of myxoma and thrombus-"all that glitters is not gold".

Left atrial appendage mass can occasionally pose a serious challenge to physicians to identify the nature of the mass with the aid of imaging techniques. We present a case of 67-year-old man, who was evaluated for suspected left atria myxoma. Transesophageal echocardiography revealed a heterogeneous density originating from left atrial appendage, thought to be most consistent with a myxoma. Cardiac magnetic resonance imaging, uncharacteristically, gave an equivocal picture, suggesting the mass to be a myxoma on initial imaging and a thrombus with evidence of liquefaction necrosis following postcontrast enhancement. Surprisingly, histopathology of the mass following its surgical excision yielded a rare diagnosis of myxofibrosarcoma.

Successful management of a rare type of complex myxofibrosarcoma which affected right lung and invading into the left atrium under the guidance of multimode image.

Myxofibrosarcoma is a rare type of highly malignant sarcoma which easily occur lung metastasis. We report a rare metastatic myxofibrosarcoma which generated from the upper and middle lobe of the lung, invading the right superior pulmonary vein, extending to the left atrium. A single imaging examination may lead to misdiagnosis, so the combination of computed tomography imaging, magnetic resonance imaging, as well as positron emission tomographic scan are necessary for perioperative diagnosis and surgical planning.