Extraskeletal Myxoid Chondrosarcoma of the Jugular Foramen in a Pediatric Patient: A Case Report and Comprehensive Review of the Literature.

INTRODUCTION: Extraskeletal myxoid chondrosarcoma of the jugular foramen is a rare clinical entity, especially in the pediatric population. Thus, it can be confused with other pathologies. CASE PRESENTATION: We report an extremely rare case of a 14-year-old female patient with jugular foramen myxoid chondrosarcoma that was completely removed through microsurgical resection. CONCLUSION: The primary purpose of the treatment is gross total resection of the chondrosarcomas. However, adjuvant methods such as radiotherapy should additionally be applied in patients who have high-grade diseases or cannot undergo gross total resection because of anatomic localization.

Calcified Chondroid Mesenchymal Neoplasm: Exploring the Morphologic and Clinical Features of an Emergent Entity With a Series of 33 Cases.

Calcified chondroid mesenchymal neoplasm is a term proposed for tumors with a spectrum of morphologic features, including cartilage/chondroid matrix formation, that frequently harbor FN1 gene fusions. We report a series of 33 cases of putative calcified chondroid mesenchymal neoplasms, mostly referred for expert consultation out of concern for malignancy. Patients included 17 males and 16 females, with a mean age of 51.3 years. Anatomic locations include the hands and fingers, feet and toes, head and neck, and temporomandibular joint; 1 patient presented with multifocal disease. Radiologic review showed soft tissue masses with variable internal calcification, which occasionally scalloped bone but in all cases appeared indolent/benign. Tumors had a mean gross size of 2.1 cm and a homogenous rubbery to fibrous/gritty tan-white cut surface. Histology demonstrated multinodular architecture with a prominent chondroid matrix and increased cellularity towards the periphery of the nodules. The tumor cells were polygonal with eccentric nuclei and bland cytologic features and showed a variable amount of increased spindled / fibroblastic forms in the perinodular septa. The majority of cases had notable grungy and/or lacy calcifications. A subset of cases demonstrated at least focal areas of increased cellularity and osteoclast-like giant cells. Herein, we confirm the distinct morphologic and clinicopathologic features associated with this entity with the largest series to date, with a focus on practical diagnostic separation from similar chondroid neoplasms. Awareness of these features is critical in avoiding pitfalls, including a malignant diagnosis of chondrosarcoma.

Extraskeletal Myxoid Chondrosarcoma of the Vulva Confirmed by EWSR1 FISH: A Case Report and Review of the Literature.

Extraskeletal myxoid chondrosarcoma of the vulva is a very rare tumor, with less than 10 cases reported in the literature. We report a case of a 45-yr-old woman with extraskeletal myxoid chondrosarcoma of the vulva confirmed by EWSR1 fluorescence in situ hybridization. Given the unusual site and prominent myxoid morphology, a broad differential diagnosis and a variety of ancillary testing was required. This article aims to review extraskeletal myxoid chondrosarcoma of the vulva, the differential diagnosis of a myxoid spindle cell neoplasm of the vulva, and the diagnostic importance of immunohistochemistry and EWSR1 fluorescence in situ hybridization.

Intra-articular Extraskeletal EWSR1-Negative NR4A3-Positive Myxoid Chondrosarcoma: A Case Report.

CASE: Extraskeletal myxoid chondrosarcomas (EMCs) are rare soft-tissue malignancies. Intra-articular occurrence is even more rare. To our knowledge, this case is one of only 2 reported intra-articular EMC cases of the knee free of local recurrence and/or amputation at follow-up. This case is also distinctive for being fluorescence in-situ hybridization-negative for the typical EMC-balanced translocation t(9;22) which fuses EWSR1 with NR4A3, harboring instead a variant translocation resulting in fusion of NR4A3 with a less common gene fusion partner. CONCLUSION: This is a unique case of intra-articular EMC of the knee with a rare molecular fingerprint and an unusually positive outcome.

The Extracompartmental Tumoral Invasion of Extraskeletal Myxoid Chondrosarcoma Induces Distant Metastasis.

BACKGROUND: Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant soft-tissue tumor and often shows extracompartmental tumoral invasion. The aim of our study was to investigate the clinical features, especially extracompartmental tumoral invasion (ETI) of EMC. PATIENTS AND METHODS: A total of 35 operative patients diagnosed with EMC were enrolled in this study from January 1980 to March 2018 in the Cancer Institute Hospital of The Japanese Foundation for Cancer Research. The operative procedure was principally wide excision. Univariate analysis assessed how clinicopathological factors (e.g. age, gender, tumor site, tumor size, histopathological grade, surgical margin, metastasis before operation, barrier invasion, local recurrence, metastasis after operation) influenced patient prognosis. We assessed how clinicopathological factors influenced ETI of EMC. RESULTS: Among 35 patients, 10 patients showed ETI. The average follow-up was 5.57 (range=0.2-20 years). The 5- and 10-year overall survival was 91.3% and 71.2%, respectively. The 5- and 10-year overall survival of patients with M0 disease was 96.1% and 73.2%, respectively, while both were 75.0% for those with M1 disease, respectively. The patients with distant metastasis at first visit tended to have a poor prognosis (p=0.07). It is notable that all of the 10 patients with ETI had distant metastasis after surgery. CONCLUSION: Patients with distant metastasis at first visit tended to have a poor prognosis. ETI of EMC induced distant metastasis after surgery. Patients with ETI of EMC should, therefore, be carefully monitored over a prolonged period.

Extraskeletal Myxoid Chondrosarcoma of the Midfoot Presenting as Charcot Arthropathy: A Case Report.

CASE: Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue malignancy that very seldomly presents in the foot or ankle and as a result is not commonly in the differential of patients presenting with foot pain. We cite a case of EMC presenting in the atypical location of the midfoot. Because of its location and similarities, this tumor was initially misdiagnosed and mistreated by multiple medical providers as midfoot Charcot arthropathy. CONCLUSIONS: Neoplastic etiologies, including EMC, should remain in the differential for atypical, refractory foot pain that presents in a manner similar to Charcot foot.

Calcified or ossified benign soft tissue lesions that may simulate malignancy.

The purpose of this article is to review calcified or ossified benign soft tissue lesions that may simulate malignancy. We review the clinical presentations, locations, imaging characteristics, and differential diagnostic considerations of myositis ossificans, tophaceous gout, benign vascular lesions, calcific tendinopathy with osseous involvement, periosteal chondroma, primary synovial chondromatosis, Hoffa's disease, tumoral calcinosis, lipoma with metaplasia, calcifying aponeurotic fibroma, calcific myonecrosis, ancient schwannoma, and Castleman disease.

Well-differentiated extraskeletal chondrosarcoma: about a new case.

Extraskeletal chondrosarcoma is a rare malignant tumor. The well differentiated histological type, which is found primary in soft tissue, is extremely rare. This report  describes the case of a 58-year-old woman presented with a large palpable mass in the right buttock. Imaging studies revealed a well-defined soft tissue mass, with extensive calcification. A histological examination after surgical resection confirmed the diagnosis of well-differentiated extraosseous chondrosarcoma. The outcome was favorable, without recurrence or metastasis.

Cardiac inflammatory myofibroblastic tumor in interventricular septum: A rare case report.

RATIONALE: Cardiac inflammatory myofibroblastic tumor (IMT) is a rare primary cardiac tumor which is currently considered as a low-grade neoplasm. The tumor has a predilection in infants and adolescents and primarily occurs as an endocardial-based cavitary mass. However, cardiac IMT that only involves the interventricular septum in middle-aged adults is extremely rarely reported. Considering its infrequency, we report a rare clinical case, with the aim of sharing our experience during the diagnostic procedures. PATIENT CONCERNS: A 45-year-old, previously healthy female, with no medical history was admitted to the outpatient clinic due to the identification of an abnormal radiographic finding during a routine health examination. DIAGNOSIS: Transthoracic echocardiography (TTE) revealed a 3.5 cm × 4.0 cm × 4.5 cm heterogeneous mass in the interventricular septum. Color Doppler echocardiography detected sparse blood flow signals inside the mass. Magnetic resonance imaging (MRI) confirmed a hyperintense T2-weighted, isointense T1-weighted mass. Three-dimensional (3D) TTE demonstrated a spherical mass in the middle part of the interventricular septum. Postoperative histopathological examinations revealed a mesenchymal tumor composed of scattered spindle myofibroblasts with a myxoid atypia, associated with infiltration of lymphocytes and plasma cells. INTERVENTIONS: Complete tumor resection was successfully performed via median sternotomy under general anesthesia. OUTCOMES: After surgery, the patient recovered successfully. The patient was in good general health without any clinical symptoms. The echocardiographic examination at the 12-month follow-up period revealed normal function of the heart, and there was no evidence of tumor recurrence. LESSONS: To our knowledge, cardiac IMT only the involving interventricular septum in a middle-aged adult has never been previously reported before. Echocardiography plays a critical role in establishing the primary diagnosis of cardiac IMT and evaluating regular follow-up examinations. Complete surgical resection of the mass is considered the first-line treatment despite the absence of symptoms.

PET in the Diagnostic Management of Soft Tissue Sarcomas of Musculoskeletal Origin.

Soft tissue sarcomas (STSs) account for less than 1% of adult solid tumors and about 7% of pediatric malignancies, causing 2% of cancer-related deaths. With the advent of PET-computed tomography (CT), the value of (18) fluorine-2-fluoro-2-deoxy-d-glucose (FDG) PET imaging to improve the management of STSs has been explored. FDG PET imaging has been found useful in restaging and treatment response assessment. This article reviews current knowledge and application of FDG PET-CT in initial diagnosis, staging, restaging, treatment response monitoring, and prognosis, with a brief overview of the most common histologic subtypes of STS.

Molecular and Clinicopathologic Heterogeneity of Intracranial Tumors Mimicking Extraskeletal Myxoid Chondrosarcoma.

Primary intracranial neoplasms with features of extraskeletal myxoid chondrosarcomas (EMC) are extremely rare and poorly characterized tumors with only ∼12 cases described, the majority lacking molecular confirmation. There is an urgent need for the integration of molecular studies for correct subclassification of these tumors in order to predict clinical behavior, guide therapeutic decision-making, and provide novel targets for therapy. Clinical and pathologic data of 3 intracranial EMC-like myxoid neoplasms were retrospectively reviewed. In 2/3 cases, immunohistochemistry showed loss of nuclear SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1; integrase interactor 1 [INI1]) staining accompanied by monosomy of chromosome 22q (fluorescence in situ hybridization [FISH]). These 2 cases had no evidence of any fusion products by next generation sequencing (NGS). The third case had intact SMARCB1 expression and showed instead a rearrangement of the EWSR1 gene detected by FISH, with an EWSR1-CREB1 gene fusion on NGS. None of the cases showed rearrangement of the NR4A3 gene, neither by FISH nor by NGS. This small case series highlights the molecular heterogeneity of intracranial neoplasms in the morphologic spectrum of EMC. Distinct molecular alterations found in tumors with morphologic features of EMC encompass SMARCB1(INI1) loss and EWSR1-CREB gene fusions. None of the cases showed rearrangements of NR4A3 genes, suggesting they are distinct from conventional EMC.

HSPA8 as a novel fusion partner of NR4A3 in extraskeletal myxoid chondrosarcoma.

Extraskeletal myxoid chondrosarcoma (EMC) is a very rare sarcoma most often arising in the soft tissue. Rare EMC of the bone have been reported. EMC exhibits distinctive clinico-pathological and genetic features; however, despite the name, it lacks any feature of cartilaginous differentiation. EMC is characterized by the rearrangement of the NR4A3, which, in most cases (about 62-75%), is fused with EWSR1 and less frequently with other partners, including TAF15 (27%), TCF12 (4%), TFG, and FUS. We herein report the identification by whole-transcriptome sequencing of HSPA8 as a novel fusion partner of NR4A3 in a case of EMC. FISH analysis confirmed the presence of a genomic HSPA8-NR4A3 translocation in the vast majority of tumor cells. Our findings expand the spectrum of NR4A3 fusion partners involved in EMC pathobiology.

Primary extraskeletal myxoid chondrosarcoma of bone: Report of three cases and review of the literature.

Extraskeletal myxoid chondrosarcoma is a rare neoplasm of soft tissue. The usual location is in deep parts of the proximal extremities and limb girdles in middle-aged adults. The bone location as primary location is extremely rare and few cases are reported. We present three cases arising in bone with molecular confirmation using both RT-PCR and FISH analysis. Patients include two men and one woman with an age of 62, 69 and 73 years old. The mean size of the lesion was 13cm (range 8-18cm). Tumors arose in the iliac bone in two cases and in the proximal humerus in the other case. At time of diagnosis the three cases show bone cortex and soft tissue involvement. On imaging, lesions have a lobular pattern, are purely lytic, but take up contrast medium after injection. Two patients are alive with disease (local recurrence and lung metastasis) after five years and five years and six months, respectively and one patient died of disease two years after the diagnosis. The primary extraskeletal myxoid chondrosarcoma of bone seems to have a more aggressive behavior than the soft tissue counterpart. The molecular confirmation of diagnosis using RT-PCR is necessary to do the differential diagnosis with other entities, in particular with myoepithelioma that shows similar morphological features and EWSR1 and FUS genes rearrangement.

Extraskeletal Myxoid Chondrosarcoma of the Orbit.

Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue tumor. Numerous cases of EMC have been reported in different anatomical locations. There is currently only a single case of EMC of the orbit and that was reported in 1985. We report a second case of orbital EMC in a 34-year-old healthy male.

Primary malignant myopericytoma of the left atrium--a tumor of aggressive biological behavior: report of the first case and review of literature.

We report a case of malignant myopericytoma arising in the left atrium with brain, skeletal, and liver metastases, which, to our knowledge, is the first report of this rare entity in this anatomic location. A 52-year-old man presented with progressive blackening of his left field of vision. Magnetic resonance imaging and a computed tomography scan of the brain and thorax showed a heterogeneous mass in the right occipital lobe and a large left atrial floor mass. Excision of the atrial mass showed a circumscribed but unencapsulated malignant spindled neoplasm with a perivascular concentric cellular arrangement punctuated by sheets of tumor necrosis. The cells were round to spindled with eosinophilic cytoplasm and indistinct borders. Focally, the tumor infiltrated cardiac muscle. By immunohistochemistry, the cells were positive for smooth muscle actin and negative for desmin, H-Caldesmon, S-100, HMB-45, and Melan-A. The features were prototypic for malignant myopericytoma. Eight months after initial presentation, the patient is alive with metastatic disease.