Myxoid tumours of soft tissue

Chordoma arising from the coccygeal disc and mimicking a pilonidal cyst

Chordomas are rare, low-grade malignant tumors often found in the sacrococcygeal region and prone to local recurrence. We report an atypical presentation of a 40-year-old patient with a symptomatic midline retrococcygeal lesion that was presumptively treated as a pilonidal cyst due to its clinical and imaging features. After surgical pathology rendered the diagnosis of chordoma, the patient required salvage surgery in the form of partial sacrectomy with soft tissue flap coverage. In addition to the unusually predominant retrococcygeal location, surgical pathology identified an intervertebral disc origin rather than the typical osseous origin. To our knowledge, this presentation of chordoma with coccygeal intervertebral origin and a large subcutaneous mass at imaging has rarely been reported in the literature. We describe this case to raise awareness of atypical presentations of sacrococcygeal chordoma that may lead to erroneous presumptive diagnosis and treatment.

Aggressive Angiomyxoma of the Lower Female Genital Tract: A Review of the MITO Rare Tumors Group

Aggressive angiomyxoma (AAM) is a rare, locally aggressive, myxoid mesenchymal neoplasm primarily found in the pelvic and perineal regions of young adult females. It is a slow growing and locally infiltrating tumor. Preoperative diagnosis is difficult due to the rarity of these tumors and absence of characteristic signs and symptoms. The primary management is tumor excision. Incomplete excision is common because of the infiltrating nature of the neoplasm and absence of a definite capsule. Other non- surgical modalities have been employed, such as radiotherapy, embolization, GnRH analogues or other anti-estrogenic agents. Local relapses occur in 30-40% of the cases, and often appear many years (sometimes decades) after the first excision. Occasional distant metastasis has also been reported. A limited number of cases have been reported in the literature, mostly in the form of small case series or isolated case reports. Therefore, the aim of this paper by a team of experts from the MITO rare tumors group is to review clinical findings, pathologic characteristics and outcome of patients affected by this rare condition in order to be able to offer up-to-date guidance on the management of these cases.

Multiple cutaneous myxofibrosarcoma on the right arm: Clinicopathological features and differential diagnosis

The clinical presentations and pathological features of low-grade myxofibrosarcoma can be misleading, frequently resulting in diagnostic errors. An accurate diagnosis requires the application of immunohistochemistry techniques and the discerning diagnostic acumen of experienced pathologists. A 62-year-old male patient visited our outpatient clinic with multiple painful and rapidly enlarging subcutaneous nodules on his right forearm. Initially, the condition was misdiagnosed as multiple lipomas. The final pathology revealed characteristics consistent with low-grade myxofibrosarcoma.

Curved Axillary Incision with Video-Assisted Thoracoscopic Surgery: An Alternative Approach for Teenage Female with Large Apical Chest Wall Tumor

Primary chest wall tumors are rare, their common clinical features are not well known, and surgical resection remains the main treatment. Apical chest wall tumors require large skin incisions and dissection of the chest wall muscles, making it difficult to maintain cosmetic appearance, respiratory function, and support of the upper extremity. There are few treatment options and no studies have reported on thoracotomy that spares muscles and preserves cosmetic superiority. However, in benign chest wall tumors in young patients, it is necessary to consider radicality, cosmetic superiority, and muscle sparing. We used a combined axillary incision and thoracoscopic approach to treat a massive myxoid neurofibroma at the apical chest wall in a 14-year-old female and were able to preserve the chest wall, upper limb function, and cosmetic aspects. This report provides a detailed description of the combined axillary incision and thoracoscopic approach for apical chest wall tumors.

Solitary superficial angiomyxoma of the ear pinna: a diagnostic dilemma with a review of literature

Superficial angiomyxoma is an extremely rare subcutaneously placed myxoid soft tissue neoplasm. There are few case reports with fine needle aspiration cytological and histopathological findings available for this tumor because of its rarity. Here, we describe a case of superficial angiomyxoma in a 24-year-old girl who had a solitary left ear pinna mass without a Carney's complex at the time of presentation or at the end of two years of follow-up next to the surgical removal of the tumor. The clinical, cytomorphological, and histological findings, together with the immunohistochemical markers, in a case of superficial angiomyxoma are described in this rare case report for the first time in the English literature.

A Case of Myxoma Mimicking Scapulothoracic Bursa

Myxoid soft tissue tumors are an unusually diverse group of neoplasms, most commonly involving the extremities. They are mesenchymal neoplasms characterized by the abundant production of myxoid matrix with a gelatinous appearance. They have varying characteristics in medical imaging and histopathology. The prognosis is variable for recurrence. Less regularly, they are found in bone, skin, the genitourinary tract, aponeurotic tissue, and subcutaneous tissue. We present a case of myxomatous tumor at the scapulothoracic region mimicking bursitis.

The T2-FLAIR mismatch sign as an imaging biomarker for oligodendrogliomas in dogs

BACKGROUND

In humans, the T2-weighted (T2W)-fluid-attenuated inversion recovery (FLAIR) mismatch sign (T2FMM) is a specific imaging biomarker for the isocitrate dehydrogenase 1 (IDH1)-mutated, 1p/19q non-codeleted low-grade astrocytomas (LGA). The T2FMM is characterized by a homogeneous hyperintense T2W signal and a hypointense signal with a hyperintense peripheral rim on FLAIR sequences. In gliomas in dogs, the T2FMM has not been described.

HYPOTHESES/OBJECTIVES

In dogs with focal intra-axial brain lesions, T2FMM will discriminate gliomas from other lesions. The T2FMM will be associated with the LGA phenotype and presence of microcysts on histopathology. Interobserver agreement for T2FMM magnetic resonance imaging (MRI) features will be high.

ANIMALS

One hundred eighty-six dogs with histopathologically diagnosed focal intra-axial lesions on brain MRI including oligodendrogliomas (n = 90), astrocytomas (n = 47), undefined gliomas (n = 9), cerebrovascular accidents (n = 33), and inflammatory lesions (n = 7).

METHODS

Two blinded raters evaluated the 186 MRI studies and identified cases with the T2FMM. Histopathologic and immunohistochemical slides of T2FMM cases were evaluated for morphologic features and IDH1-mutations and compared to cases without the T2FMM. Gene expression analyses were performed on a subset of oligodendrogliomas (n = 10) with and without T2FMM.

RESULTS

The T2FMM was identified in 14/186 (8%) of MRI studies, and all dogs with T2FMM had oligodendrogliomas (n = 12 low-grade [LGO], n = 2 high-grade [HGO]; P < .001). Microcystic change was significantly associated with the T2FMM (P < .00001). In oligodendrogliomas with T2FMM, IDH1-mutations or specific differentially expressed genes were not identified.

CONCLUSION AND CLINICAL IMPORTANCE

The T2FMM can be readily identified on routinely obtained MRI sequences. It is a specific biomarker for oligodendroglioma in dogs, and was significantly associated with non-enhancing LGO.

Imaging features of myxoid soft-tissue tumours

Myxoid soft-tissue tumours are mesenchymal neoplasms, which are characterised by the production of abundant extracellular myxoid matrix. Imaging plays an important role in the diagnosis of these tumours as well as treatment planning. The imaging features as well as the clinical course for these lesions are highly variable, depending on both the anatomical location of the tumour and the histopathological subtype. This article, illustrated by histopathologically proven cases from our tertiary referral soft-tissue sarcoma centre, reviews the spectrum of imaging findings and characteristic signs seen with different types of benign and malignant myxoid soft-tissue neoplasms.

Approach to FNA of Myxoid Soft Tissue Tumors

Myxoid tumors of the soft tissue encompass a group of heterogenous tumors that are characterized by the presence of abundant extracellular myxoid or chondromyxoid matrix material. Fine needle aspiration (FNA) is variably used for diagnosing primary, recurrent, and metastatic myxoid soft tissue tumors. The spectrum of myxoid soft tissue tumors encountered in practice ranges from benign lesions such as simple ganglion cysts to high-grade malignant sarcomas such as myxofibrosarcoma. These myxoid tumors have clinical, cytologic, and histologic overlap. Therefore, making an accurate diagnosis by FNA alone is challenging. Despite this challenge, using a systematic cytomorphologic approach and ancillary studies, an accurate diagnosis is feasible in the majority of cases. This article provides a systematic approach to diagnosing myxoid soft tissue tumors by FNA along with a review of the literature.

Texture analysis of magnetic resonance image to differentiate benign from malignant myxoid soft tissue tumors: A retrospective comparative study

It is important to differentiate between benign and malignant myxoid tumors to establish the treatment plan, determine the optimal surgical extent, and plan postoperative surveillance, but differentiation may be complicated by imaging-feature overlap. Texture analysis is used for quantitative assessment of imaging characteristics based on mathematically calculated pixel heterogeneity and has been applied to the discrimination of benign from malignant soft tissue tumors (STTs). In this study, we aimed to assess the diagnostic value of the texture features of conventional magnetic resonance images for the differentiation of benign from malignant myxoid STTs. Magnetic resonance images of 39 patients with histologically confirmed myxoid STTs of the extremities were analyzed. Qualitative features were assessed and compared between the benign and malignant groups. Texture analysis was performed, and texture features were selected based on univariate analysis and Fisher’s coefficient. The diagnostic value of the texture features was assessed using receiver operating curve analysis. T1 heterogeneity showed a statistically significant difference between benign and malignant myxoid STTs, with substantial inter-reader reliability. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of T1 heterogeneity were 55.6%, 83.3%, 88.2%, 45.5%, and 64.1%, respectively. Among the texture features, T2w-WavEnLL_s-3 showed good diagnostic performance, and T2w-WavEnLL_s-4 and GeoW4 showed fair diagnostic performance. The logistic regression model including T1 heterogeneity and T2_WavEnLL_s-4 showed good diagnostic performance. However, there was no statistically significant difference between the overall qualitative assessment by a radiologist and the predictor model. Geometry-based and wavelet-derived texture features from T2-weighted images were significantly different between benign and malignant myxoid STTs. However, the texture features had a limited additive value in differentiating benign from malignant myxoid STTs.

Artificial intelligence significantly improves the diagnostic accuracy of deep myxoid soft tissue lesions in histology

Deep myxoid soft tissue lesions have posed a diagnostic challenge for pathologists due to significant histological overlap and regional heterogeneity, especially when dealing with small biopsies which have profoundly low accuracy. However, accurate diagnosis is important owing to difference in biological behaviors and response to adjuvant therapy, that will guide the extent of surgery and the need for neo-adjuvant therapy. Herein, we trained two convolutional neural network models based on a total of 149,130 images representing diagnoses of extra skeletal myxoid chondrosarcoma, intramuscular myxoma, low-grade fibromyxoid sarcoma, myxofibrosarcoma and myxoid liposarcoma. Both AI models outperformed all the pathologists, with a significant improvement of accuracy up to 97% compared to average pathologists of 69.7% (p < 0.00001), corresponding to 90% reduction in error rate. The area under curve of the best AI model was on average 0.9976. It could assist pathologists in clinical practice for accurate diagnosis of deep soft tissue myxoid lesions, and guide clinicians for precise and optimal treatment for patients.

The Extracellular Matrix in Soft Tissue Sarcomas: Pathobiology and Cellular Signalling

Soft tissue sarcomas are rare cancers of mesenchymal origin or differentiation comprising over 70 different histological subtypes. Due to their mesenchymal differentiation, sarcomas are thought to produce and deposit large quantities of extracellular matrix (ECM) components. Interactions between ECM ligands and their corresponding adhesion receptors such as the integrins and the discoidin domain receptors play key roles in driving many fundamental oncogenic processes including uncontrolled proliferation, cellular invasion and altered metabolism. In this review, we focus on emerging studies that describe the key ECM components commonly found in soft tissue sarcomas and discuss preclinical and clinical evidence outlining the important role that these proteins and their cognate adhesion receptors play in sarcomagenesis. We conclude by providing a perspective on the need for more comprehensive in-depth analyses of both the ECM and adhesion receptor biology in multiple histological subtypes in order to identify new drug targets and prognostic biomarkers for this group of rare diseases of unmet need.

Aggressive angiomyxoma of vulva in 28-years old patient: A case report of second recurrence

Introduction

Aggressive angiomyxoma is an uncommon mesenchymal tumor in women who are in reproductive age, that occurring in the pelvis and perineal zone with a high risk of local infiltration and recurrence.

Case presentation

We describe a case of a 28-year-old woman with a huge recurrent vulvar aggressive angiomyxoma.

Clinical Discussion

Our patients underwent surgery and tumor resection for two times but had relapsed every 2 years through 5 years and finally she underwent total vulvectomy. The patient received Decapeptide for 3 months to prevent tumor recurrence after surgery and to date,there has been no evidence of local recurrence.

Conclusion

Aggressive angiomyxoma is a rare tumor with high recurrence rate. The best treatment is surgical resection by experienced Gyn-oncologist in teamwork and territory Hospital.

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Aggressive angiomyxoma has a high trend to local recurrence.

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Radical surgery with wide margins is the first line of treatment.

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All patients counseled about the need for long-term surveillance.

Radiomic Phenotypes Distinguish Atypical Teratoid/Rhabdoid Tumors from Medulloblastoma

BACKGROUND AND PURPOSE

Atypical teratoid/rhabdoid tumors and medulloblastomas have similar imaging and histologic features but distinctly different outcomes. We hypothesized that they could be distinguished by MR imaging-based radiomic phenotypes.

MATERIALS AND METHODS

We retrospectively assembled T2-weighted and gadolinium-enhanced T1-weighted images of 48 posterior fossa atypical teratoid/rhabdoid tumors and 96 match-paired medulloblastomas from 7 institutions. Using a holdout test set, we measured the performance of 6 candidate classifier models using 6 imaging features derived by sparse regression of 900 T2WI and 900 T1WI Imaging Biomarker Standardization Initiative-based radiomics features.

RESULTS

From the originally extracted 1800 total Imaging Biomarker Standardization Initiative-based features, sparse regression consistently reduced the feature set to 1 from T1WI and 5 from T2WI. Among classifier models, logistic regression performed with the highest AUC of 0.86, with sensitivity, specificity, accuracy, and F1 scores of 0.80, 0.82, 0.81, and 0.85, respectively. The top 3 important Imaging Biomarker Standardization Initiative features, by decreasing order of relative contribution, included voxel intensity at the 90th percentile, inverse difference moment normalized, and kurtosis-all from T2WI.

CONCLUSIONS

Six quantitative signatures of image intensity, texture, and morphology distinguish atypical teratoid/rhabdoid tumors from medulloblastomas with high prediction performance across different machine learning strategies. Use of this technique for preoperative diagnosis of atypical teratoid/rhabdoid tumors could significantly inform therapeutic strategies and patient care discussions.

Atrial myxomas arise from multipotent cardiac stem cells

Aims

Cardiac myxomas usually develop in the atria and consist of an acid-mucopolysaccharide-rich myxoid matrix with polygonal stromal cells scattered throughout. These human benign tumours are a valuable research model because of the rarity of cardiac tumours, their clinical presentation and uncertain origin. Here, we assessed whether multipotent cardiac stem/progenitor cells (CSCs) give rise to atrial myxoma tissue.

Methods and results

Twenty-three myxomas were collected and analysed for the presence of multipotent CSCs. We detected myxoma cells positive for c-kit (c-kit^pos) but very rare Isl-1 positive cells. Most of the c-kit^pos cells were blood lineage-committed CD45^pos/CD31^pos cells. However, c-kit^pos/CD45^neg/CD31^neg cardiac myxoma cells expressed stemness and cardiac progenitor cell transcription factors. Approximately ≤10% of the c-kit^pos/CD45^neg/CD31^neg myxoma cells also expressed calretinin, a characteristic of myxoma stromal cells. In vitro, the c-kit^pos/CD45^neg/CD31^neg myxoma cells secrete chondroitin-6-sulfate and hyaluronic acid, which are the main components of gelatinous myxoma matrix in vivo. In vitro, c-kit^pos/CD45^neg/CD31^neg myxoma cells have stem cell properties being clonogenic, self-renewing, and sphere forming while exhibiting an abortive cardiac differentiation potential. Myxoma-derived CSCs possess a mRNA and microRNA transcriptome overall similar to normal myocardium-derived c-kit^pos/CD45^neg/CD31^negCSCs , yet showing a relatively small and relevant fraction of dysregulated mRNA/miRNAs (miR-126-3p and miR-335-5p, in particular). Importantly, myxoma-derived CSCs but not normal myocardium-derived CSCs, seed human myxoma tumours in xenograft’s in immunodeficient NOD/SCID mice.

Conclusion

Myxoma-derived c-kit^pos/CD45^neg/CD31^neg CSCs fulfill the criteria expected of atrial myxoma-initiating stem cells. The transcriptome of these cells indicates that they belong to or are derived from the same lineage as the atrial multipotent c-kit^pos/CD45^neg/CD31^neg CSCs. Taken together the data presented here suggest that human myxomas could be the first-described CSC-related human heart disease.

Aggressive angiomyxoma in pregnancy: A rare and commonly misdiagnosed entity

Aggressive angiomyxoma (AAM) is an uncommon mesenchymal tumor that predominantly involves the pelvis and perineum of young females. It is often clinically mistaken for more common superficial lesions such as vaginal cysts, labial cysts, and lipomas. A review of the medical literature reveals very few cases of AAM reported in pregnancy. We describe a rare case of AAM in pregnancy, clinically misdiagnosed as prolapsed cervical fibroid.

Myxoid Liposarcoma With Skeletal Metastases: Pathophysiology and Imaging Characteristics

Liposarcoma is a commonly occurring soft tissue sarcoma that can be divided into 4 subtypes. Myxoid and round cell liposarcoma (MRCL) represent one of these subtypes and are classified together due to their shared chromosomal translocation. Histologic analysis of MRCL reveals a myxoid matrix with a delicate capillary network and dispersed lipoblasts. Varying degrees of round cell component are also observed, with greater amounts of round cells indicating a higher histologic grade and poorer prognosis. MRCL has a unique pattern of spread due to its initial tendency to spread to extrapulmonary sites. Additionally, skeletal metastases are frequently found in cases of MRCL. While various imaging techniques are used to visualize MRCL and metastases, magnetic resonance imaging is generally the preferred method. This article reviews the pathophysiology and imaging features of MRCL as well as the imaging characteristics, advantages, and drawbacks of multiple imaging modalities for visualizing bone metastases.

[Myxoid soft tissue tumours : An algorithm for differential diagnosis]

Soft tissue neoplasms with myxoid features are collectively not uncommon. Their often complex differential diagnosis makes them significantly over-represented among consultation cases. This applies not only to sarcomas but in particular to benign lesions as well. Generally, myxoid soft tissue lesions are divided into two major groups: (1) myxoid lesions by definition (which can however rarely be non-myxoid) and (2) rare myxoid variants of otherwise non-myxoid entities.Four major diagnostic challenges are responsible for the complexity of myxoid soft tissue neoplasms: (1) Diagnosis of malignancy in many cases is not based on conventional malignancy criteria but is defined by the entity itself, making under-diagnosis of malignancy likely in entities such as low-grade fibromyxoid sarcoma. (2) On the other hand, harmless myxoid lesions with features of high proliferation, e.g. nodular and proliferative fasciitis, tend to be over-diagnosed as malignant by the unworried. (3) The necessity to assess not only cellular morphology/differentiation, but also the stromal, vascular and architectural characteristics adds to the complexity of the differential diagnostic algorithm. (4) Last but not least, recognition of unexpected myxoid variants of non-myxoid entities is basically impossible if focal conventional areas are absent, underlining the need for high suspicion index and sufficient sampling.This review illuminates the various aspects related to the differential diagnostic workup of these challenging entities.

Calreticulin as A Novel Potential Metastasis-Associated Protein in Myxoid Liposarcoma, as Revealed by Two-Dimensional Difference Gel Electrophoresis

Myxoid liposarcoma (MLS) is a mesenchymal malignancy. To identify innovate seeds for clinical applications, we examined the proteomes of primary tumor tissues from 10 patients with MLS with different statuses of postoperative metastasis. The protein expression profiles of tumor tissues were created, and proteins with differential expression associated with postoperative metastasis were identified by two-dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry. The validation was performed using specific antibodies and in vitro analyses. Using 2D-DIGE, we observed 1726 protein species and identified proteins with unique expression levels in metastatic MLS. We focused on the overexpression of calreticulin in metastatic MLS. The higher expression of calreticulin was confirmed by Western blotting, and gene silencing assays demonstrated that reduced expression of calreticulin inhibited cell growth and invasion. Our findings suggested the important roles of calreticulin in MLS metastasis and supported its potential utility as a prognostic biomarker in MLS. Further investigations of the functional properties of calreticulin and other proteins identified in this study will improve our understanding of the biology of MLS and facilitate novel clinical applications.

A contemporary review of myxoid adipocytic tumors

Myxoid adipocytic tumors encompass a broad heterogeneous group of benign and malignant adipocytic tumors, which are typically myxoid (e.g. myxoid liposarcoma, lipoblastoma and lipoblastoma-like tumor of the vulva) or may occasionally appear predominantly myxoid (e.g. pleomorphic liposarcoma, atypical lipomatous tumor, dedifferentiated liposarcoma, chondroid lipoma, spindle cell/pleomorphic lipoma, atypical spindle cell lipomatous tumor and atypical pleomorphic lipomatous tumor). There have been significant advances in recent years in classification and understanding the pathogenesis of adipocytic tumors, based on the correlation of histologic, immunohistochemical, and cytogenetic/molecular findings. Despite these advances, the morphologic diagnosis and accurate classification of a myxoid adipocytic tumor can be challenging due to major morphologic overlap between myxoid adipocytic and non-adipocytic tumors. This article will provide a review on the currently known morphological, immunohistochemical and molecular features of myxoid adipocytic tumors and their differential diagnosis.

Detection of GNAS mutations in intramuscular / cellular myxomas as diagnostic tool in the classification of myxoid soft tissue tumors

BACKGROUND

Intramuscular / cellular myxomas and low-grade myxofibrosarcomas are two different tumor entities with a significant histological overlap, especially if dealing with small biopsies. Despite the morphological similarities, they differ considerably in their biological behaviour. Intramuscular / cellular myxoma rarely shows signs of recurrence and never metastasizes, in contrast to myxofibrosarcoma that tends to recur more aggressively and to metastasize haematologically. Therefore, it is of great importance to distinguish these lesions - evaluation of GNAS mutation status could be of tremendous help.

METHODS

We reviewed 13 cases with intramuscular / cellular myxomas. The 13 cases included 5 men and 8 women, aged from 33 to 71 years (mean age 55.5 years). Immunohistochemistry was performed as well as next generation sequencing. Ten cases were located in the lower extremities and three cases were located in the upper extremities. Two lesions were initially misdiagnosed as a low-grade myxofibrosarcoma.

RESULTS

Performing next generation sequencing 12 out of 13 specimens showed a GNAS mutation.

CONCLUSIONS

Our findings demonstrate that GNAS mutations are more common in intramuscular / cellular myxomas, than had been reported in literature in the past. Next generation sequencing for determining GNAS mutation status on small biopsies or diagnostically challenging cases facilitates the diagnosis of intramuscular / cellular myxoma and separates this tumor entity from its mimics.

Primary cardiac myxofibrosarcoma: case report, literature review and pooled analysis

Background

Primary cardiac myxofibrosarcoma is a very rare cardiac malignancy. The majority of publications are limited to case reports. No pooled analyses of primary cardiac myxofibrosarcoma cases are available. Little clinical features and outcome patterns are acknowledged. The purpose of this study is to identify the clinical characteristics and prognostic factors of primary cardiac myxofibrosarcoma.

Case presentation

A case report of primary cardiac myxofibrosarcoma was presented, and a review of English language literatures of primary cardiac myxofibrosarcomas were performed electronically. Demographics, clinicopathologic data, therapy and follow-up were summarized. The median survival time and the mean survival time were calculated by Kaplan-Meier method. Survival distribution and overall survival were figured by log-rank test and cox proportional hazards models. We present a case, and retrospectively analyzed additional 30 patients derived from 24 isolated articles. The cohort consisted of 18 male and 13 female patients. The age was 41.87 ± 17.89 years. Some common features were found in clinical presentations, pathologic features, treatments and outcome patterns of primary cardiac myxofibrosarcoma. There were special features in echocardiography, histological and immunohistochemical examinations, which should be considered in diagnosis of primary cardiac myxofibrosarcoma. The median survival time/mean survival time (MST) was 14/32.66 months. The median survival time/mean survival time (MST) was 14/32.66 months. Compared to the other groups, the following groups had shorter survival characteristics, including age ≥ 40 years (14/11.79 months), female (14/26.26 months), mass diameter ≥ 40 mm (14/14.64 months), high-grade (2/11.81 months), and no post-treatment (14/28.09 months). Statistical analyses revealed that primary cardiac myxofibrosarcomas were more likely to present with local recurrences and dismal metastases. Tumors ≥ 40 mm in size (P = 0.055, HR = 6.79) or with high-grade (P = 0.063, HR = 11.45) had significantly worse prognosis.

Conclusions

Primary cardiac myxofibrosarcomas were more likely to present with local recurrences and dismal metastases. Echocardiography, together with histological method should be considered in ordinary diagnosis. Tumors ≥ 40 mm in size or with high-grade had significantly worse prognosis, which should be early diagnosed and treated with rational surgery.

Fibromyxoma of the Jaw: Case Report and Review of the Literature

We report a case of fibromyxoma of the mandible, a rare benign odontogenic tumor. Our patient presented in the first trimester of pregnancy with a large mass in the right body of the mandible exhibiting displacement of teeth and destruction of an extensive area of the mandibular bone. The mass was biopsied and diagnosed as a fibromyxoma. The large size of the tumor dictated a wide mandibular resection. We will review the clinical, radiographic, and histologic features of fibromyxoma and discuss its differential diagnoses. In addition, we will provide an overview of patient management. Fibromxyoma is a benign gnathic tumor that can be locally aggressive. To ensure appropriate treatment, it is important to distinguish this neoplasm from other mimickers in which myxoid, spindle mesenchymal cell proliferation is prominent.

Cyto-Histo Correlation of a Very Rare Tumor: Superficial Angiomyxoma

Superficial angiomyxoma (SA) is one of the superficially located myxoid soft tissue tumor. Because of the rarity of this tumor, there is paucity of fine needle aspiration cytology (FNAC) findings. Here, we present a case of SA in a 14-year-old girl who presented with a left leg swelling. The cytology of the lesion along with the histopathologic correlation is presented.

Clinicopathological analysis of myxoid proximal-type epithelioid sarcoma

Proximal-type epithelioid sarcoma (ES) with a diffuse myxoid stroma is rare. Here, we report the case of a 33-year-old man with a perineal mass. Imaging showed the presence of a poorly demarcated 6.9 × 5.3-cm mass in the subcutaneous perineal region. Macroscopic examination showed that the resected tissues were partially necrotic. Histological examination showed that the tumor comprised numerous large or pleomorphic epithelioid cells with large vesicular nuclei and prominent nucleoli. A clear background of necrosis and inflammatory exudates was also present. Immunohistochemical examination showed that the tumor cells were positive for vimentin and CD34 - both of which were expressed throughout the cytoplasm - but typically did not express nuclear INI1 (SMARCB1). Hematoxylin-eosin staining (HE staining) showed that the mucin content of the tumor was approximately 80%. The patient was diagnosed with proximal-type ES with myxoid features. The patient died due to disease progression after 2 months of follow-up and without undergoing further treatment in our department. To our knowledge, only 2 cases of proximal-type ES with diffuse myxoid stroma have been reported. Proximal-type ES is rare, and this is the first case report of proximal ES with myxoid features in the perineal area.

Malignant renal schwannoma in a cat

A nine-year-old male European shorthair cat with rapidly enlarging mass at the left kidney doubted to be malignant was presented. The purpose of this study is to present the clinical, radiological and pathological findings of a primary renal tumor in the cat. Grossly, the mass mostly encapsulated the kidney. Histologically, excisional biopsy showed worrying histological features. A sarcoma-like tumor composed mainly of neoplastic spindle-shaped cells. Neoplastic nodules of aggregations of fusiform cells arranged in multidirectional bundles. Immunohistochemically, several immunohistochemical satins (melan-A, S-100, vimentin, actin, desmin, cytokeratin, neurofilament, melan-A, NSE, synaptophysin, chromogranin, Glial Fibrillary Acidic Protein GFAP, Collagen IV and CD99) were used to differentially diagnose the mass. The stained neoplastic sections positively tested to S-100, but negative to the other aforementioned immunohistochemical stains. Immunohistochemistry with S-100 antibody staining showed an unusually strong positive reaction throughout the tumor cells. Based on our comparative diagnosis relative to other tumors, in addition to the progressive clinical signs, histopathological and immunohistochemical results, this case was presumptively diagnosis as a malignant schwannoma. According to our investigation of the relevant literature, this study of malignant renal Schwannoma (malignant peripheral nerve sheath tumor) is a highly rare case not previously characterized in a cat.

Tumor spatial heterogeneity in myxoid-containing soft tissue using texture analysis of diffusion-weighted MRI

The objective of this study was to examine the tumor spatial heterogeneity in myxoid-containing soft-tissue tumors (STTs) using texture analysis of diffusion-weighted imaging (DWI). A total of 40 patients with myxoid-containing STTs (23 benign and 17 malignant) were included in this study. The region of interest (ROI) was manually drawn on the apparent diffusion coefficient (ADC) map. For texture analysis, the global (mean, standard deviation, skewness, and kurtosis), regional (intensity variability and size-zone variability), and local features (energy, entropy, correlation, contrast, homogeneity, variance, and maximum probability) were extracted from the ADC map. Student’s t-test was used to test the difference between group means. Analysis of covariance (ANCOVA) was performed with adjustments for age, sex, and tumor volume. The receiver operating characteristic (ROC) analysis was performed to compare diagnostic performances. Malignant myxoid-containing STTs had significantly higher kurtosis (P = 0.040), energy (P = 0.034), correlation (P<0.001), and homogeneity (P = 0.003), but significantly lower contrast (P<0.001) and variance (P = 0.001) compared with benign myxoid-containing STTs. Contrast showed the highest area under the curve (AUC = 0.923, P<0.001), sensitivity (94.12%), and specificity (86.96%). Our results reveal the potential utility of texture analysis of ADC maps for differentiating benign and malignant myxoid-containing STTs.

Diagnostic performance of conventional MRI parameters and apparent diffusion coefficient values in differentiating between benign and malignant soft-tissue tumours

AIM

To compare the abilities of conventional magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) in differentiating between benign and malignant soft-tissue tumours (STT).

MATERIAL AND METHODS

A total of 123 patients with STT who underwent 3 T MRI, including diffusion-weighted imaging (DWI), were retrospectively analysed using variate conventional MRI parameters, ADC_mean and ADC_min.

RESULTS

For the all-STT group, the correlation between the malignant STT conventional MRI parameters, except deep compartment involvement, compared to those of benign STT were statistically significant with univariate analysis. Maximum diameter of the tumour (p=0.001; odds ratio [OR], 8.97) and ADC_mean (p=0.020; OR, 4.30) were independent factors with multivariate analysis. For the non-myxoid non-haemosiderin STT group, signal heterogeneity on axial T1-weighted imaging (T1WI; p=0.017), ADC_mean, and ADC_min (p=0.001, p=0.001), showed significant differences with univariate analysis between malignancy and benignity. Signal heterogeneity in axial T1WI (p=0.025; OR, 12.64) and ADC_mean (p=0.004; OR, 33.15) were independent factors with multivariate analysis.

CONCLUSION

ADC values as well as conventional MRI parameters were useful in differentiating between benign and malignant STT. The ADC_mean was the most powerful diagnostic parameter in non-myxoid non-haemosiderin STT.

Primary rhabdomyosarcoma of the thyroid in an adult with auricular thrombosis

INTRODUCTION

Rhabdomyoscarcoma (RMS) is the most common soft-part tumour in children, however, it is infrequent in adults. Thyroid involvement is exceptional and only four cases have been reported: two primary RMS in children and another two cases in young adults with RMS metastasis to the thyroid. We report the first case in the literature of a primary adult RMS with thyroid involvement and superior vena cava syndrome.

CASE PRESENTATION

A 67-year-old male was admitted for an oedema of the arm extending to the laterocervical region. Computed tomography showed a 6cm mass in the hemithyroid with venous thrombosis to the auricle. Fine-needle aspiration was compatible with Bethesda category III. Surgery revealed a stone-hard consistency thyroid. An intraoperative biopsy showed an undifferentiated neoplasia, and no additional surgical intervention was undertaken. The patient died 48hours later. Definitive histology showed a RMS.

DISCUSSION

Venous thrombosis due to a thyroid tumour is infrequent. The scarce information in the literature recommends that thyroid carcinomas with auricular thrombosis be resected as soon as they are diagnosed. However, in cases of anaplastic or poorly differentiated carcinomas is controversial. Had there been a preoperative diagnosis in the histology in our case, surgery would not have been indicated.

Giant myxofibrosarcoma of the orbit: a rare case and a review of the literature

A 65-year-old man presented with giant orbital myxofibrosarcoma with no extraorbital extension. Imaging was suggestive of mesenchymal malignancy with significant vascularity. Incisional biopsy was suggestive of low-grade fibromyxoid sarcoma. The clinical and imaging features did not support the pathological diagnosis. Histopathology of the exenterated sample revealed features of high-grade myxofibrosarcoma. To the best of our knowledge, this is the largest reported myxofibrosarcoma of the orbit. Adjuvant radiotherapy was advised. Correlating the case history, imaging and histopathology, this case can best be summarised as a natural history of conversion from a low to high-grade myxoid malignancy. We emphasise that the overlapping features of myxoid malignancy (fibromyxosarcoma vs myxofibrosarcoma) and regional variation in tumour morphology in biopsy specimen may mislead the clinician. Therefore, knowledge about the key differentiating features as well as incisional biopsy of each radiologically different area can increase the possibility of correct diagnosis and management of each case.

Myxoid mesenchymal neoplasm presenting as massive arm and chest wall oedema with pleural effusion

Myxoid mesenchymal tumours are a heterogeneous group of neoplasms characterised histologically by their abundant mucoid and myxoid extracellular matrix (ECM). Encompassing a broad spectrum of clinical behaviour ranging from benign to malignant, there are more than 60 reactive and neoplastic entities currently classified under its domain. Its varied clinical and histopathologic features continue to pose a diagnostic challenge to clinicians and pathologists. Here, we describe a rare case of myxoid mesenchymal tumour presenting as oedema of the upper extremity with pleural metastasis and partial response to chemotherapy, which to the best of our knowledge has not yet been described in the literature.

Soft-tissue myxomatous lesions: review of salient imaging features with pathologic comparison

Myxoid soft-tissue lesions are a heterogeneous group of benign and malignant mesenchymal tumors with an abundance of extracellular mucoid material. These lesions may mimic cysts on radiologic evaluation because of the high water content, and histopathologic features also overlap. Benign myxoid lesions include intramuscular myxoma, synovial cyst, bursa, ganglion, and benign peripheral nerve sheath tumor, including neurofibroma and schwannoma. Malignant entities include myxoid liposarcoma, myxoid leiomyosarcoma, myxoid chondrosarcoma, ossifying fibromyxoid tumor, and myxofibrosarcoma. Some syndromes are associated with myxoid soft-tissue lesions, such as Mazabraud syndrome in patients with soft-tissue myxomas and fibrous dysplasia. Certain discriminating features, such as intralesional fat in a myxoid liposarcoma, perilesional edema and a rim of fat in soft-tissue myxoma, and the swirled T2-weighted signal intensity and enhancement pattern of aggressive angiomyxoma, assist the radiologist in differentiating these lesions. The presence of an internal chondroid matrix or incomplete peripheral ossification may suggest myxoid chondrosarcoma or ossifying fibromyxoid tumor, respectively. The entering-and-exiting-nerve sign is suggestive of a peripheral nerve sheath tumor. Communication with a joint or tendon sheath and peripheral enhancement may indicate a ganglion or synovial cyst. This article (a) reviews the magnetic resonance, computed tomographic, and ultrasonographic imaging characteristics of soft-tissue myxomatous lesions, emphasizing imaging findings that can help differentiate benign and malignant lesions; (b) presents differential diagnoses; and (c) provides pathologic correlation.

Intramuscular myxoma of the paraspinal muscles: A case report and systematic review of the literature

Intramuscular myxoma (IM) is a rare mesenchymal tumor of the head and neck region. The current study reports a case of a 45-year-old man who presented with a painless neck mass. Imaging showed involvement of the levator scapulae and scalene muscles. Core needle biopsy was consistent with intramuscular myxoma. Surgical excision was performed and follow-up for 30 months showed no recurrence. The present study includes a systematic review of head and neck IMs, with a summary of the clinical and demographic parameters of all reported cases in the head and neck region. Surgery was curative in 28 of the 29 published cases, as well as in the current case (96.7%), with the lone recurrent tumor cured following re-resection. Females constituted 57% of the cases and the mean age was 49.7±20.4 years. Although uncommon, IM should be considered in the differential diagnosis of deep neck masses, and surgical excision is the treatment of choice with a low risk of recurrence.

Squamous Cell Carcinoma Arising From Massive Localized Lymphedema of Scrotum Mimicking Scrotal Smooth Muscle Hamartoma of Dartos: A Case Report

Massive localized lymphedema (MLL) is an uncommon benign skin lesion typically presenting with prominent edema and vascular proliferation in the adipose tissue of lower limbs. When rarely occurring in scrotum, it instead is characterized by a striking proliferation of dermal smooth muscle bundles mimicking acquired smooth muscle hamartoma of dartos. The authors report a rare case of scrotal MLL. A 57-year-old obese man with a history of previous surgery for rectal adenocarcinoma, 20 years earlier, presented with progressive nodular enlargement of the scrotum for 2 years, causing discomfort, difficulty in ambulation, and cosmetic problems. The preoperative radiographic investigation revealed thickening of the scrotal wall with multiple soft-tissue nodules. The patient underwent a wide excision of the scrotal wall, perineum, and penile skin. The pathological examination showed a scrotal MLL associated with well-differentiated squamous cell carcinoma. The authors speculate that prior radiotherapy and surgery together with morbid obesity led to long-standing lymphedema that triggered the proliferation of smooth muscle cells, chronic epidermal change, and finally squamous cell carcinoma.

Myxoid soft-tissue neoplasms: comprehensive update of the taxonomy and MRI features

OBJECTIVE. The purpose of this article is to review the classification, clinical presentation, and histopathologic and MRI features of myxoid soft-tissue neoplasms. CONCLUSION. MRI is the modality of choice for characterization of myxoid soft-tissue tumors. A combination of imaging features (including certain characteristic signs), clinical features, and patient demographics can help the radiologist in coming to a specific diagnosis or in narrowing down the differential diagnoses.

STUMP un"stumped": anti-tumor response to anaplastic lymphoma kinase (ALK) inhibitor based targeted therapy in uterine inflammatory myofibroblastic tumor with myxoid features harboring DCTN1-ALK fusion

BACKGROUND

Recurrent, metastatic mesenchymal myxoid tumors of the gynecologic tract present a management challenge as there is minimal evidence to guide systemic therapy. Such tumors also present a diagnostic dilemma, as myxoid features are observed in leiomyosarcomas, inflammatory myofibroblastic tumors (IMT), and mesenchymal myxoid tumors. Comprehensive genomic profiling was performed in the course of clinical care on a case of a recurrent, metastatic myxoid uterine malignancy (initially diagnosed as smooth muscle tumor of uncertain malignant potential (STUMP)), to guide identify targeted therapeutic options. To our knowledge, this case represents the first report of clinical response to targeted therapy in a tumor harboring a DCTN1-ALK fusion protein.

METHODS

Hybridization capture of 315 cancer-related genes plus introns from 28 genes often rearranged or altered in cancer was applied to >50 ng of DNA extracted from this sample and sequenced to high, uniform coverage. Therapy was given in the context of a phase I clinical trial ClinicalTrials.gov Identifier: ( NCT01548144 ).

RESULTS

Immunostains showed diffuse positivity for ALK1 expression and comprehensive genomic profiling identified an in frame DCTN1-ALK gene fusion. The diagnosis of STUMP was revised to that of an IMT with myxoid features. The patient was enrolled in a clinical trial and treated with an anaplastic lymphoma kinase (ALK) inhibitor (crizotinib/Xalkori®) and a multikinase VEGF inhibitor (pazopanib/Votrient®). The patient experienced an ongoing partial response (6+ months) by response evaluation criteria in solid tumors (RECIST) 1.1 criteria.

CONCLUSIONS

For myxoid tumors of the gynecologic tract, comprehensive genomic profiling can identify clinical relevant genomic alterations that both direct treatment targeted therapy and help discriminate between similar diagnostic entities.

Primary renal myxofibrosarcoma

Kidney sarcomas are rare, representing only 1% of malignant renal tumors. We herein report the case of a 70-year-old woman that was admitted for an episode of confusion in relation to hypertensive encephalopathy. Imaging investigations revealed a large mass in the right kidney with extension to the renal hilum. The patient underwent right open radical nephrectomy. The histopathologic study disclosed a 15-cm, myxoid and cellular, pleomorphic tumor with elongated, curvilinear, thin-walled vessels, and focal necrosis that involved the upper and middle segments of the kidney. Immunohistochemically, the tumor cells showed strong positivity for vimentin, bcl2 protein (nuclear staining pattern), CD34, CD99, and alpha-methylacyl coenzyme A racemase. The tumor was diagnosed as myxofibrosarcoma (MFS) grade 2 according to the FNCLCC system. To the best of our knowledge, this is the first report of an MFS arising from the kidney. Thus, MFS is an uncommon soft tissue tumor that can exceptionally arise from the kidney. The differential diagnosis with other myxoid tumors is of vital importance because it includes lesions with subtle differences and extremely variable biological behavior. Radical surgery is the treatment of choice. Long-term follow-up is recommended because of the tumor's capability for local recurrence and distant metastasis.

Cell cycle and apoptosis regulatory proteins, proliferative markers, cell signaling molecules, CD209, and decorin immunoreactivity in low-grade myxofibrosarcoma and myxoma

The histologic differential diagnosis between intramuscular myxoma and low-grade myxofibrosarcoma can be quite difficult in some cases. To identify a diagnostic immunohistochemical marker, we compared the staining profiles of 19 different antigens, including cell cycle proteins, apoptosis proteins, and proliferative markers, and selected other signaling and structural proteins in these two tumors. Ten cases each of intramuscular myxoma and low-grade myxofibrosarcoma were stained with antibodies directed against apoptosis regulatory proteins (Bcl2, activated caspase-3, phospho-H2A.X, and cleaved PARP), cell cycle regulatory proteins (Rb1, Cyclin-A, CDKN1B, and Cdt1), proliferative markers (KI67, MCM2, phospho-histone H3, and geminin), cell signalling molecules (c-Myc, EGF, EGFR, PLA2G4A, and HSP90), a dendritic cell marker (CD209), and the extracellular matrix proteoglycan decorin. Staining patterns of myxoma and myxofibrosarcoma were compared using Fisher's exact test and the Mann-Whitney test. For each potential diagnostic marker studied, the proportions of cases scored as positive on both dichotomous or ordinal scales were not significantly different between myxoma and myxofibrosarcoma. Myxoma and myxofibrosarcoma share a common immunophenotype for each of the markers studied. Distinction between these tumors is still predominantly based on morphologic criteria.