Gene of the month: DDIT3

DNA damage-inducible transcript 3 (DDIT3) gene, mapped to the human chromosome 12q13.3, encodes a protein that belongs to the CCAAT/enhancer-binding protein family of transcription factors. DDIT3 is involved in the proliferative control that responds to endoplasmic reticulum stress in normal conditions, dimerising other transcription factors with basic leucine zipper (bZIP) structural motifs. DDIT3 plays a significant role during cell differentiation, especially adipogenesis, arresting the maturation of adipoblasts. In disease, FUS/EWSR1::DDIT3 fusion is the pathogenic event that drives the development of myxoid liposarcoma. The amplification of DDIT3 in other adipocytic neoplasms mediates the presence of adipoblast-like elements. Another fusion, GLI1::DDIT3, has rarely been documented in other tumours. This paper reviews the structure and function of DDIT3, its role in disease-particularly cancer-and its use and pitfalls in diagnostic testing, including immunohistochemistry as a tissue-based marker.

Distribution and Rate of Myxoid Liposarcoma Spine Metastases: Impact on Surveillance Imaging

BACKGROUND

Myxoid liposarcoma (LPS) has a unique tendency to spread to extrapulmonary sites, including osseous sites such as the spine, and adjacent sites such as the paraspinous tissue. No clear consensus exists to guide the approach to imaging in these patients.

OBJECTIVE

The aim of this study was to investigate the rate and distribution of spine metastases in patients with myxoid LPS and detection modality.

METHODS

Records of all patients with myxoid LPS evaluated at our sarcoma center were retrospectively reviewed. Disease patterns and imaging modality utilization were analyzed.

RESULTS

Between 2000 and 2020, 164 patients with myxoid LPS were identified. The majority (n = 148, 90%) presented with localized disease, with half (n = 82, 50%) of all patients developing metastases or recurrence during their disease course. With a median follow-up of 69.2 months, spine/paraspinous metastases developed in 38 patients (23%), of whom 35 (92%) already had synchronous, non-spine metastases. Spine disease was only visible on magnetic resonance imaging (MRI), as opposed to other imaging modalities, for over one-quarter of patients with spine metastases (n = 10). For patients with metastatic disease, spine metastases were associated with worse median overall survival (2.1 vs. 8.7 years, p < 0.001).

CONCLUSION

Spine metastases occurred in nearly one-quarter of patients with myxoid LPS and represented an advanced disease state, as they primarily presented in the setting of synchronous, non-spine metastases, and were associated with worse overall survival. Routine surveillance with spine MRI in patients with localized disease likely provides no benefit but may be considered in those with known metastatic disease.

Primary Orbital Myxoid Liposarcoma

Although liposarcoma is the most prevalent soft tissue sarcoma in adults, head and neck liposarcomas are rare and account for less than 5% of all liposarcomas. The primary orbital location is even more exceptional, with fewer than 100 cases documented in the medical literature. Given the scarcity of cases of orbital liposarcoma and the limited familiarity of physicians and pathologists with this pathology, there is an increased risk of non-diagnosis or misdiagnosis, which may lead to inappropriate patient management. To address these challenges, we present a case of primary orbital myxoid liposarcoma and subsequently discuss the primary findings of this case based on the evidence documented in the medical literature. This comprehensive text is designed to serve as a valuable resource for healthcare professionals and pathologists, with the goal of promoting both clinical suspicion and accurate diagnosis and treatment of this rare condition in future cases.

Myxoid pleomorphic liposarcoma in the teres minor muscle: A case report

RATIONALE

Myxoid pleomorphic liposarcoma (MPL) is a rare aggressive adipocytic tumor that mainly presents in children and adolescents. It is most frequently observed in the mediastinum and rarely in the head and neck, perineal region, or back. Herein, we report the first published case of MPL of the teres minor muscle.

PATIENT CONCERNS

A 24-years-old woman presented with a painless palpable mass in her right shoulder.

DIAGNOSES

Magnetic resonance imaging identified a 9.0 × 7.0 × 4.0 cm mass suspected to be a sarcoma in the teres minor muscle. Positron emission tomography/computed tomography revealed no evidence of distant metastasis. Histopathological examination revealed the mass to be an MPL, which was assigned a histologic grade of 3 according to the French Federation of Cancer Centers Sarcoma Group system. No tumor cells were observed along the resected margins.

INTERVENTIONS

Under general anesthesia, the right teres minor muscle containing the mass was excised en bloc and frozen biopsy confirmed that the tumor cells did not invade the surrounding tissues.

OUTCOMES

The patient underwent radiotherapy and was followed up for 6 months without complications.

LESSONS

Although MPL in the teres minor muscle is rare, it should be considered in the differential diagnosis in patients with a mass in the teres minor muscle due to its poor prognosis.

[Myxiod pleomorphic liposarcoma: a clinicopathological and molecular genetic analysis of six cases]

Objective: To investigate the clinicopathologic and molecular genetic characteristics of myxoid pleomorphic liposarcoma (MPLPS). Methods: Six cases of MPLPS diagnosed and consulted in Fujian Provincial Hospital from 2015 to 2021 were collected for histomorphological observation, immunohistochemistry, and fluorescence in situ hybridization (FISH) detection of DDIT3 (CHOP) gene translocation and MDM2/CDK4 gene amplification. Results: There were four males and two females, aged 26-74 years (mean 53.8 years). The tumor size was 3.8-16.0 cm (mean 11.8 cm). All six cases had similar histopathologic features, showing overlapping histologic morphology of myxoid liposarcoma and pleomorphic liposarcoma. Four cases (4/6) were positive for S-100 protein, and the Ki-67 index was 50%-95%. All cases (6/6) were negative for DDIT3 (CHOP) translocation and MDM2/CDK4 amplification by FISH. TP53 (p.R248w) germline mutation was found in one case. Conclusions: MPLPS is a rare subtype of liposarcoma, characterized by overlapping morphology of myxoid liposarcoma and pleomorphic liposarcoma. Genetically, a few of them have TP53 gene germline mutations, but they lack of DDIT3 (CHOP) translocation or MDM2/CDK4 amplification.

The utility of fluorescence in situ hybridization (FISH) in determining DNA damage-inducible transcript 3 (DDIT3) amplification in dedifferentiated liposarcomas - an important diagnostic pitfall

BACKGROUND AND OBJECTIVE

Dedifferentiated liposarcoma (DDLPS) is characterized by non-lipogenic sarcoma fields coexisting with adipocyte-rich well-differentiated areas. Amplification of the 12q13-15 region includes the MDM2 and DDIT3 genes. MDM2 amplification is considered a genetic hallmark of DDLPS, while DDIT3 is typically rearranged in myxoid liposarcoma. Recent studies showed that DDIT3 amplification is associated with myxoid liposarcoma-like (LPS-like) morphology in DDLPS. Our study aimed to evaluate the status of MDM2 and DDIT3 by FISH in DDLPS and correlate it with MLPS-like features.

MATERIAL AND METHODS

Six patients with MLPS-like morphology DDLPS were investigated pathologically, immunohistochemically, and genetically. The control groups of patients with classical DDLPS morphology and well-differentiated liposarcoma (WDLPS) were established and molecularly assessed as well. Fluorescence in situ hybridization (FISH) used in routine diagnostics was performed to determine the status of MDM2 and DDIT3 genes.

RESULTS

The patient's mean age was 64 (range from 43 to 85 years) with a 5:4 male to female ratio. Tumors were localized retroperitoneally (15) and extra-retroperitoneally (3). All cases demonstrated amplification of the 12q15 region containing MDM2 gene and co-amplification of the 5' DDIT3 FISH Probe representing DDIT3 telomeric tag. However, we did not find the relation of myxoid LPS-like morphology with DDIT3 amplification as previously reported.

CONCLUSIONS

The biopsy material from DDLPS with myxoid areas can be misclassified as myxoid liposarcoma. Indeed, according to the histological image, DDIT3 status may be evaluated first. In these cases, we show that the DDIT3 telomeric tag amplification assessed by FISH, is a common, nonspecific feature, which is also found in classical DDLPS and WDLPS. Therefore, we believe that co-amplification of DDIT3 and MDM2 may be considered a spectrum of the 12q13-15 region amplification due to the specification of FISH methodology.

DDIT3 Immunohistochemistry Is a Useful Tool for the Diagnosis of Myxoid Liposarcoma

Myxoid liposarcoma is a malignant adipogenic neoplasm characterized by prominent arborizing capillaries, occasional lipoblasts, and primitive-appearing spindle cells in a myxoid background. A recurrent translocation in myxoid liposarcoma results in an oncoprotein consisting of full-length DDIT3 (CHOP) fused to an N-terminal segment of either FUS (TLS) or, less often, EWSR1. Here, we explore the diagnostic significance of DDIT3 expression in myxoid liposarcoma using a mouse monoclonal antibody recognizing an epitope in the N-terminal region. Studying a total of 300 tumors, we find diffuse, moderate-to-strong nuclear-localized anti-DDIT3 immunoreactivity in all 46 cases of myxoid liposarcoma representing 36 unique tumors, including 6 cases with high-grade (round cell) morphology. DDIT3 immunohistochemistry also highlighted a distinctive vasculocentric growth pattern in 7 myxoid liposarcomas treated with neoadjuvant radiation. In contrast, the vast majority of other examined lipomatous and myxoid neoplasms exhibited no DDIT3 expression; limited, weak immunoreactivity in <10% of cells was infrequently observed in dedifferentiated liposarcoma (6/39, 15%), solitary fibrous tumor (3/12, 25%), pleomorphic liposarcoma (1/15, 7%), and high-grade myxofibrosarcoma (2/17, 12%). Although this minimal DDIT3 expression did not correlate with DDIT3 amplification or myxoid liposarcoma-like morphology in dedifferentiated liposarcoma, there was evidence among sarcomas (excluding myxoid liposarcoma) of a relationship between expression and exposure to neoadjuvant radiation or cytotoxic chemotherapy. The constellation of findings indicates that DDIT3 immunohistochemistry may have utility in the evaluation of myxoid and lipomatous neoplasms to support the diagnosis of myxoid liposarcoma.

DIscBIO: A User-Friendly Pipeline for Biomarker Discovery in Single-Cell Transcriptomics

The growing attention toward the benefits of single-cell RNA sequencing (scRNA-seq) is leading to a myriad of computational packages for the analysis of different aspects of scRNA-seq data. For researchers without advanced programing skills, it is very challenging to combine several packages in order to perform the desired analysis in a simple and reproducible way. Here we present DIscBIO, an open-source, multi-algorithmic pipeline for easy, efficient and reproducible analysis of cellular sub-populations at the transcriptomic level. The pipeline integrates multiple scRNA-seq packages and allows biomarker discovery with decision trees and gene enrichment analysis in a network context using single-cell sequencing read counts through clustering and differential analysis. DIscBIO is freely available as an R package. It can be run either in command-line mode or through a user-friendly computational pipeline using Jupyter notebooks. We showcase all pipeline features using two scRNA-seq datasets. The first dataset consists of circulating tumor cells from patients with breast cancer. The second one is a cell cycle regulation dataset in myxoid liposarcoma. All analyses are available as notebooks that integrate in a sequential narrative R code with explanatory text and output data and images. R users can use the notebooks to understand the different steps of the pipeline and will guide them to explore their scRNA-seq data. We also provide a cloud version using Binder that allows the execution of the pipeline without the need of downloading R, Jupyter or any of the packages used by the pipeline. The cloud version can serve as a tutorial for training purposes, especially for those that are not R users or have limited programing skills. However, in order to do meaningful scRNA-seq analyses, all users will need to understand the implemented methods and their possible options and limitations.

[Liposarcoma in the renal compartment: about two cases and literature review]

Retroperitoneal sarcomas are rare and heterogeneous tumors. We here report two cases of liposarcoma in the renal compartment with a literature review in order to emphasize on the anatomical and surgical features of this tumor location and on its possible prognostic implications. The first reported case was a 45-year old female patient with liposarcoma at the level of the left renal compartment. The diagnosis of myxoid liposarcoma was based on anatomo-pathological examination of the surgical specimen. The second reported case was a 70-year old man with liposarcoma at the level of the right renal compartment. The diagnosis of dedifferentiated liposarcoma was based on anatomo-pathological examination of the surgical specimen. Retroperitoneal sarcomas are often diagnosed with a palpable mass. The gold standard treatment is complete tumor resection with healthy resection margins and without damage or rupture. For this purpose resection involving adjacent organs is recommended by some authors. However the anatomical constraints of tretroperitoneal compartment and the often important tumor volume limit the possibilities to achieve a satisfactory resection. CT scan and MRI are very useful imaging techniques. Histological diagnosis poses some problems; therefore immunohistochemistry and sometimes molecular biology are significantly helpful. Patient evolution is marked by the frequent occurrence of recurrences. A specialized multidisciplinary management of these rare and very varied tumors is recommended in order to optimize therapeutic outcomes.

[Myxoid liposarcoma localised in the peritoneal cavity case report]

INTRODUCTION

Liposarcoma is one of rare soft tissue tumours. Usually, it is localised in soft tissues of the extremities, can however be localised even in body cavities. The prognosis depends on the localisation and differentiation of the tumour.

CASE REPORT

We present a patient indicated for surgical revision due to recurrence (or persistence) after previous surgery and debulking of a myxoid liposarcoma. Laparotomy with debulking, low anterior rectal resection with coloanal anastomosis, and protective ileostomy were done. No adverse events occurred in the postoperative period. However, another recurrence was observed in the subsequent follow-up.

CONCLUSION

Myxoid liposarcoma is a rare tumour with a relatively good prognosis when radically removed; in case of intraperitoneal localisation it however remains a virtually unsolvable problem.Key words: liposarcoma - debulking recurrence.

Myxoid liposarcoma in the abdominal wall: a case report

A liposarcoma is the most common type of soft tissue sarcoma, and most liposarcomas are malignant. The extremities are the most common site for liposarcomas. There are 5 histologic types of liposarcoma, as follows: well differentiated; myxoid; round cell; pleomorphic; and dedifferentiated. Myxoid liposarcomas (MLSs) represent a subgroup of liposarcomas. There has been no report of MLSs in the abdominal wall. We report a rare case of a MLS of a 43-year-old male who presented with tensile force on the abdominal wall. Computed tomography (CT) found a tumor in abdominal wall. There was no other abnormal symptom and the laboratory testing was also unusual. At last, the tumor was successfully excised, which was diagnosed MLSs in pathology. Following standard principles, after complete excision, the patient received radiotherapy. The patient was followed up for 8 month and no disease recurrence was identified. MLSs are rarely seen in the clinic, irrespective of the presenting signs, but also based on histologic features. The aim of this report was to present the differential diagnosis of an abdominal wall mass, and to remind us of MLSs.

[Myxoid liposarcoma of the anterior mediastinum. A case report and bibliography review]

Five cases per year. Of those cases 50% are located in the extremities and 40% are located in the trunk and retroperitoneum. Primary mediastinal liposarcomas represent less than 1% of mediastinal tumors.

CLINICAL CASE

A 53 year old female, native and resident of Tabasco, with a history of anterior mediastinal tumor was treated with resection at the National Institute of Cancerology about 16 years ago with histopathological diagnosis of pleomorphic liposarcoma. She started her condition with chest pain, cough and hyaline expectoration, managed as pneumonia in her unit. Other symptoms occurred, moderate exertion dyspnea and edema of lower limbs, chest computed tomography prompted for documenting mediastinal tumor measured to be 9 × 9 cm and sent to our unit which is managed with resection.

Myxoid liposarcoma of the spermatic cord: US and MR imaging findings

We report a patient with myxoid liposarcoma of the spermatic cord in whom combined use of both ultrasound (US) and MRI helped to suggest the diagnosis. The lesion was solid at US and vascularized at color Doppler. T1-weighted MRI did not show fat within it; on T2-weighted images it had high signal intensity, with a cyst-like appearance. It is known that fat-poor myxoid liposarcomas with high water content may mimic a cystic lesion on non-contrast-enhanced MR; then, a combination of MRI findings, suggesting a cyst, and of US findings, showing the mass was actually solid and vascularized, allowed preoperatively the diagnosis of fat-poor myxoid liposarcoma.

[Myxoid liposarcoma of the lumbosacral spine. Clinical case report]

BACKGROUND

liposarcoma is a malignant tumor of soft tissue and the most common sarcoma in the adult life. The myxoid liposarcoma accounts for 30 to 35 % of all liposarcomas. It is commonly seen on the thighs. Only two cases in which the liposarcoma was found in the vertebral column have been reported.

CLINICAL CASE

this is a 28 year old woman with symptoms of spinal cord injury by compression (tottering gait, weakness 4/5 and decreased sensibility in right leg). The MRI showed a right paravertebral multinodular mass from L4 to S2, with solid and cystic aspects, following the S1 and S2 intervertebral foramen to the presacral space, with low signal intensity on T1 and high on T2. The diagnosis of neurofibroma was concluded. The patient was scheduled for surgery. Extra and intraspinal excision was performed and a mass was removed. Histopathologic study reported myxoid liposarcoma.

CONCLUSIONS

liposarcoma is a malignant tumor of soft tissues. The spine is a rare location for this neoplasm, even for metastases. It is difficult to achieve a complete resection in this localization, so the recurrence rate is high.

Resection of soft tissue tumors extending through the obturator ring

Pelvic soft tissue sarcomas are rare tumors often presenting larger than other soft tissue sarcomas and can extend into the thigh through various anatomic routes. Surgical resection is the main modality of curative treatment. En bloc tumor excision with wide, negative margins may reduce the risk of local recurrence. Soft tissue sarcomas extending through the obturator foramen create unique challenges to operative management. This case report describes 2 cases of lipomatous lesions that extend through the obturator foramen, presenting as dumbbell-shaped lesions with large intra- and extrapelvis portions. One possible surgical approach performed in both patients is detailed with long-term follow-up. Postoperatively, 1 incidence of infection was reported. Functional outcomes were acceptable, with full restoration of ambulation without assistive devices in both cases and no hernia observed. Oncologic outcomes included locoregional recurrence in 1 patient at 24 months outside the radiation field. The ideal primary treatment for all localized soft tissue sarcomas, including those extending through the obturator foramen, is resection. However, the unique subgroup of obturator ring soft tissue sarcomas has undefined outcomes and complications. The authors' goal was to achieve en bloc resection with wide negative margins while preserving ipsilateral limb function. The surgical approach described in this case study offers a description of feasibility and discussion of theoretical and observed complications.

Myxoid lipoblastoma

A rapidly growing soft tissue mass in the axilla of an infant raises the suspicion of a lipoblastoma or a liposarcoma. Excisional/incisional biopsy is vital in confirming the diagnosis and hence avoiding aggressive extirpation. This case report highlights the role of histopathology and immunohistochemistry as the gold standard in differentiating a lipoblastoma from a liposarcoma. In some cases where the histopathology is inconclusive, genetic rearrangement of the PLAG1 (pleomorphic adenoma gene 1) oncogene on chromosome 8q12 helps in confirming the diagnosis of lipoblastoma.

Myxofibrosarcoma: cytomorphologic findings and differential diagnosis on fine needle aspiration

OBJECTIVE

To analyze the cytomorphologic findings of myxofibrosarcoma (MFS) on fine needle aspiration (FNA) and examine the differential diagnoses.

STUDY DESIGN

A retrospective review was undertaken of material from 22 patients with an FNA procedure of their tumor prior to resection. A tally was performed of all the features known in the literature, including myxoid matrix, spindle cells, nuclear pleomorphism, curvilinear vessels, and multinucleated cells. A review of the literature was also performed to elucidate any advances in the use of morphology and other modalities to deconvolute the challenging differential diagnosis. Clinicoradiologic characteristics and immunostaining were also analyzed and correlated.

RESULTS

FNA diagnoses included high-grade sarcoma (32%), recurrent MFS (23%), spindle cell neoplasm (18%), indeterminate-grade sarcoma (14%), low-grade sarcoma (9%), and pleomorphic adenoma (4%). Of the cases available for morphologic review, myxoid matrix was the most frequent observation (88%), followed by spindle cells (82%), nuclear pleomorphism (76%), multinucleated cells (71%), and curvilinear vessels (65%). Myxoid matrix, spindle cells, and nuclear pleomorphism were very often concomitant observations.

CONCLUSION

MFS demonstrates characteristic albeit nonspecific morphological findings and can overlap morphologically with other clinically significant entities based on FNA material.

Something inside the heart: a myxoid liposarcoma with cardiac involvement

A 70-year-old man presented with dry cough, dyspnea and fatigue. Physical examination revealed only a grade 3 heart murmur. The chest X-ray showed bilateral nodular opacities. A CT scan revealed several nodular masses in both lungs, pleura and abdomen, as well as a similar lesion inside the left ventricle. Echocardiography revealed not only the pedunculated nature of this lesion, but also infiltration of the ventricular wall. Biopsy showed it to be a myxoid liposarcoma. Since the disease was already widespread, and given the characteristics of the intraventricular mass, only palliative measures were prescribed.

Liposarcoma of the extremities: MR imaging features and their correlation with pathologic data

OBJECTIVE

To describe the MRI features of liposarcomas of the extremities and correlate them with data from the histologic subtypes.

MATERIAL AND METHODS

Retrospective study of 20 cases of liposarcoma of the extremities identified on MRI, surgically removed and confirmed at pathology. On MRI examination, T1- and T2-weighted fat-suppressed and non-fat-suppressed images were acquired then gadolinium-enhanced fat-suppressed T1-weighted images were obtained in at least two orthogonal planes.

RESULTS

Sixteen female and four male patients aged 12 to 77 years old at presentation, in 16 cases, with a slowly enlarging painless mass (demonstrating no associated local or general inflammatory components), located in the lower extremity (16 cases) and predominantly located in the thigh (13 cases). Pathologic examination revealed three cases of well-differentiated liposarcoma, 12 cases of myxoid liposarcoma one of which with round cells, three cases of pleomorphic liposarcoma, one case of dedifferentiated liposarcoma and one case of mixed-type liposarcoma. MR images mostly showed well-circumscribed tumors (19 cases) . Well-differentiated liposarcomas typically demonstrated a very specific diagnostic appearance as a predominantly adipose mass containing nonlipomatous components seen as thick septa that may show nodularity. Other subtypes of liposarcoma demonstrated a small amount of adipose tissue thus producing a marbled textural pattern on T1-weighted images particularly in myxoid liposarcomas (9 cases), or even nonlipomatous elements in high-grade liposarcomas (in round cell liposarcoma and in two out of three pleomorphic liposarcomas). The myxoid subtype has also a relatively characteristic appearance as a low signal intensity noted on T1-weighted images and a marked high signal intensity on T2. The dedifferentiated liposarcoma has a very specific radiologic appearance as a nonlipomatous component within a predominantly adipose mass, simulating that of well-differentiated liposarcomas.

CONCLUSION

MRI of extremity liposarcomas is a highly reliable and sensitive method to characterize liposarcomas. Besides its value in the diagnosis of liposarcoma and locoregional extension control, it allows proper identification of the specific histologic subtypes of liposarcoma.

LEVEL OF EVIDENCE

Level IV. Rétrospective diagnostic study.

Myxoid liposarcoma with EWS-CHOP type 1 fusion gene

BACKGROUND

In myxoid liposarcoma (MLS), the t(12;16)(q13;p11) chromosomal translocation and its resultant fusion transcript, the human translocation liposarcoma (TLS)-CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP), are found in the majority of cases. On the other hand, the variant translocation, t(12;22)(q13;q12) creating the Ewing sarcoma (EWS)-CHOP fusion transcript, is detectable in a limited number of cases.

PATIENTS AND METHODS

Tissue from MLS arising in the left thigh of a 19-year-old female was analyzed for possible detection of chromosome translocation and fusion transcript. Fluorescent in situ hybridization (FISH) and reverse transcription-polymerase chain reaction (RT-PCR) methods were used.

RESULTS

FISH analysis demonstrated a rearrangement in the CHOP gene. RT-PCR analysis confirmed the presence of EWS-CHOP chimeric transcript type 1, in which exon 7 of EWS was in-frame fused to exon 2 of CHOP with a serine (AGT) to methionine (ATG) transition at the junction. The patient underwent a radical segmental resection including a left vastus medialis musclectomy. Sixty months following the surgical resection, the patient was alive with no evidence of disease.

CONCLUSION

Analysis of MLS with EWS-CHOP variant transcripts, type 1 through type 4, including this case together with 15 cases in the literature, indicated that MLS with type 1 fusion transcript may show a more favorable clinical behavior than MLS with other types of fusion transcript.

[Myxoid liposarcoma]

Soft-tissue sarcoma is a rare pathology. Due to restricted symptomatology, the diagnosis is often late. Any soft tissues swelling requires at first an ultrasound exam and a radiography, though MRI remains the most appropriate investigation. Treatment will be selected according to the tumor type and its histological grading, these parameters being determined after a surgical or a needle biopsy. The surgical care is often complemented by radiotherapy and sometimes chemotherapy.

Case report: two-step malignant transformation of a liposclerosing myxofibrous tumor of bone

We present the case of a patient with malignant transformation of a liposclerosing myxofibrous tumor. The patient had a histologically confirmed liposclerosing myxofibrous tumor that, during a course of 22 months, spontaneously transformed into a lesion appearing like a benign giant cell reactive lesion and subsequently into a high-grade bone sarcoma. Few such cases of spontaneous malignant transformation of liposclerosing myxofibrous tumor have been reported. We report what we believe to be the first case documenting spontaneous transformation of a liposclerosing myxofibrous tumor into an intermediate lesion with benign-appearing histologic features and then into a high-grade malignant tumor.

Spermatic cord mixed liposarcoma. Case report and review of the literature

A 75-years-old man presented with a clinical diagnosis of hydrocele. Grossly examination revealed a large (14x8x9 cm) tumor. Histologically, the tumor had a mixed pattern, with major pleomorphic and a minor sclerosing well-differentiated component. The anatomo-clinical features, the prognosis and the principles of treatment of this rare condition are shortly discussed.

Spinal metastases from myxoid liposarcoma warrant screening with magnetic resonance imaging

BACKGROUND

Myxoid liposarcoma (MLS) has an unusual tendency for extrapulmonary metastasis, particularly to the spine and soft tissues. The objective of this study was to determine the prevalence of spinal metastasis, treatment outcomes, and optimal screening method for spinal metastasis in patients with MLS.

METHODS

Data from patients with had spinal metastases were obtained from the authors' institutional soft tissue sarcoma database. The accuracy with which positron emission tomography (PET) scans and bone scans identified metastatic lesions was compared with the accuracy of magnetic resonance imaging (MRI). Clinical response to treatment was based on pain, neurologic scores, and survivorship analysis.

RESULTS

There were 33 patients who developed spinal metastasis after a median 36 months of follow-up (range, from 7.5 months to 33 years). Known spinal metastases were detected by bone scans in 16% of patients and by PET scans in 14% of patients. Patients who underwent surgery had high-grade spinal cord compression more often than patients who did not undergo surgery (72% vs 19%, respectively; P = .002). Pain and neurologic function were improved or maintained in all patients who received radiation alone (n = 8 patients) and in all but 1 patient who underwent surgery (n = 18 patients). The median overall survival was 51.4 months from the time of primary diagnosis and 21.9 months from the time of first metastasis.

CONCLUSIONS

Bone scans and PET scan lack sufficient sensitivity to detect spinal metastasis from MLS. Treatment of metastasis is palliative, but local treatment can yield long-term disease control in select patients. Screening with whole-spine MRI may lead to the earlier detection of spinal metastasis.

An unusual presentation of myxoid liposarcoma: a case report

A 50 year old female had a myxoid liposarcoma of left thigh that was widely excised. After three years, she presented with a soft tissue mass in right hypochondriac region, which was diagnosed as myxoid liposarcoma on fine needle aspiration cytology (FNAC) and was confirmed histologically.

[Liposarcoma histologic subtypes: four cases reports]

The liposarcoma is a malignant tumor of mesodermic origin derived of the adipose tissue. Liposarcoma s types, according to his histological diagnosis, are: mixoide, pleomorphic, well differentiated and dedifferentiated. It can get to reach enormous proportions, mainly when it is located at abdominal level. His treatment is the radical surgery, it is possible, together with radiation therapy and/or chemotherapy. Four patients diagnosed of liposarcoma are shown up, a case of liposarcoma well differentiated, another case of liposarcoma pleomorphic and two cases about liposarcoma mixoide; with the characteristic that one of these two cases presented a local recidivation with a dediferenciation of itself. The evolution of the four cases, was in a different way. So, their prognosis is going to depend on their histopathologic variety and on a possible multicentricidad that is going to difficult the complete radical surgical exeresis.

Liposarcoma of the retropharyngeal space: Report of a case and review of literature

Liposarcoma is a soft tissue malignant tumor that is common in adults, though the incidence of this type of tumor in the head and neck region is extremely low. Herein, we report a case of myxoid liposarcoma occurring in the retropharyngeal space. We were unable to make a proper diagnosis of this tumor prior to surgery because of the radiographic findings and the anatomical location resembled those of neurogenic tumor. Myxoid liposarcoma often recurs. So its excision must be carried out carefully and radical dissection is recommended. In the past, liposarcomas arising in the retropharyngeal space were not radically resected because the extent of resection in the head and neck area risked poor functional outcome. In the present case, functional resection and radiotherapy were performed and proved to be efficacious in that no recurrence was observed for 2 years.

Paratesticular myxoid liposarcoma: a case report

Liposarcoma of the paratesticular region is a rare malignant soft tissue neoplasm. Out of all the possible sites of liposarcoma, the incidence in spermatic cord is rare, accounting for only 5% of these neoplasms. Among the various subtypes of liposarcoma described in the paratesticular region, myxoid variant of liposarcoma is seen very rarely. One such case is we ported here for its rarity and also to draw attention to the fact that, early diagnosis and complete excision carry better prognostic value.

Giant lesser sac liposarcoma mimicking infected pancreatic pseudocyst

The most common site for abdominal liposarcoma is the retroperitoneum. We report a 32-year-old man with lesser-sac myxoid liposarcoma with extensive cystic degeneration. Cystogastrostomy was attempted elsewhere with a misdiagnosis of pancreatic pseudocyst. However, the procedure was abandoned after biopsy, which showed features of liposarcoma. The patient was re-explored at our institute 2 weeks later. Complete excision of the tumor was done. Histology revealed features of myxoid liposarcoma. The patient received adjuvant radiotherapy and is doing well 12 months later.

[Benign mesenchymal stromal tumor of the breast simulating benign schwannoma in an 81-year-old male--a case report]

Presented is an unusual case of a benign mesenchymal stromal tumor of the breast in an 81-year-old male. The basic appearance of the lesion simulated benign schwannoma and was misinterpreted as a low-grade myxoid liposarcoma initially. Well-circumscribed, gray-white mass measuring 35 mm in maximum diameter was discovered deep in the parenchyma of the completely removed breast. Microscopically, the lesion consisted of myxoid, richly vascular background where dominated oval or spindle cells with impressive palisading replicating that of benign schwannoma. Rarely, the large multinucleated (floret-like type) cells were visible; no nuclear atypia or mitotic figures were found. Immunohistochemical examination confirmed expression of estrogen and progesterone receptors, antigen Bcl2 and also focal desmin positivity. Clinical examinations disclosed no objective reason for possible hyperestrinism; no other therapy followed and the patient is free of disease 19 months after operation. On the background of both detailed review and differential diagnosis of benign, so-called stromal tumor of the female breast, the rarity of this microscopic finding in male is documented.

[A case of myxoid liposarcoma in the right inguinal region: a case report]

We report a case of myxoid liposarcoma developed in the right inguinal region. A 45-year-old man visited our hospital with a chief complaint of painless right inguinal mass. He was diagnosed with right direct inguinal hernia for the first time and received a hernia repair. However, the size of the inguinal mass increased gradually after the operation. Then, the tumor was re-evaluated by imaging study such as ultrasonography, computed tomography and magnetic resonance imaging. A fatty mass 4.0 cm in diameter was demonstrated and the tumor was diagnosed as a liposarcoma preoperatively. In addition to the right high orchiectomy, surrounding fatty tissue was also removed at the time of the operation. Histological examination revealed a myxoid liposarcoma and the existence of several daughter regions outside the pseudo-capsule. Right spermatic cord and testis were intact. Postoperatively, he received 54 Gy dose of radiation therapy to right inguinal region for the prevention of the local recurrence of the disease.

Isolated pancreatic metastasis of extremity myxoid liposarcoma: Report of a case

Myxoid liposarcoma (ML) has a high predilection for extrapulmonary sites of metastases, including intra-abdominal metastases, but pancreatic involvement is extremely rare. Here, we report the case of a 66-year-old male patient, who underwent pancreaticoduodenectomy for isolated pancreatic metastasis of ML of the left lower extremity that had been excised 6 years before. Completion pancreatectomy was necessitated afterwards for a delayed haemorrage associated with pancreatic fistula. Currently the patient is alive with no evidence of disease. Highly selected patients with isolated pancreatic metastasis of soft tissue sarcoma may benefit from a curative surgical resection.

Myxoid liposarcoma of the breast--report of a rare case

Breast sarcomas are very rare. A 40 year old lady presented with a well-defined hard lump, 6 cm in size, in the left breast. Patient underwent simple mastectomy with axillary clearance following a diagnosis of phylloides tumour on fine needle aspiration cytology. Grossly, it was a circumscribed myxoid tumour. Histopathologically, it fulfilled all the criteria for a diagnosis of myxoid liposarcoma. The absence of epithelial component excluded phylloides tumour.

Lower-extremity liposarcoma metastatic to the larynx: case report

Distant metastases to the larynx are rare. We describe the case of a 46-year-old man who was referred to our head and neck surgery clinic with a 6-week history of sore throat and otalgia. He was found to have a laryngeal lesion that was consistent with a primary myxoid liposarcoma that had been extirpated from a lower extremity earlier To the best of our knowledge, no case of myxoid liposarcoma metastatic to the larynx has been previously reported in the English-language literature.

Liposarcoma causing left ventricular outflow tract obstruction and syncope: a case report and review of the literature

Metastatic cardiac myxoid liposarcoma is rare. We present the case of a 56-year-old woman who was admitted for angina and syncope, and in whom a mobile intracardiac mass obstructing the left ventricular outflow tract and protruding into the aortic root during systole was detected by transesophageal echocardiography (TEE). She reported an antecedent of the complete excision of a myxoid liposarcoma of the thigh 12 years before. A surgical resection procedure was performed through an excision of the anterior wall of the left ventricle. The histopathological analysis of the specimens obtained during surgery revealed a low-grade malignancy myxoid liposarcoma, similar to the one resected in the thigh 12 years before. The present case is the first one to report syncope due to left ventricular outflow tract as a cause for admission. TEE was able to visualize the metastatic tumor to the heart, accurately localize its position and allow for prompt surgical treatment that produced relief of the symptoms.

Metastatic myxoid liposarcoma in the mesentery: what is debated? Case report and a review of the literature

Myxoid liposarcoma, unlike other types of liposarcoma, has an unusual propensity to metastasize to extrapulmonary sites including the abdominal cavity. Metastatic myxoid liposarcoma is an important condition because it may indicate distant micrometastatic disease. We report the case of a 47-year-old woman with a metastatic myxoid liposarcoma in the mesentery. Surgical excision with a tumor-free margin was achieved, but cardiac and liver metastases developed. We review the available literature and discuss what is still debated about this disease.

Pericardial metastasis of myxoid liposarcoma causing cardiac tamponade

Although myxoid liposarcoma often metastasizes to various organs, cardiac metastasis is rare. We present herein a rare case with pericardial metastasis of myxoid liposarcoma, which expanded the pericardial sac extraordinarily and required an emergency operation because of acute cardiac tamponade. We undertook a review of the English literature regarding liposarcoma.

Chondroid lipoma of the trunk: MRI appearance and pathologic correlation

Chondroid lipoma is a rare tumour of adipose tissue, bearing a strikingly close pathologic resemblance to myxoid liposarcoma and extraskeletal myxoid chondrosarcoma. Unlike these malignant tumours, chondroid lipoma has a non-aggressive behaviour and does not require radical treatment. Although repeatedly reported in the proximal extremities and limb girdles, this rare entity may less frequently be observed in the trunk. We describe the imaging findings of a chondroid lipoma in the trunk and provide a discussion on the radiologic-pathologic correlation and differential diagnosis.

Unusual skeletal metastases from myxoid liposarcoma only detectable by MR imaging

We present two cases of skeletal metastases from myxoid liposarcoma, occurring several years after treatment of the primary tumors in the lower limb. The present two case reports have unusual radiological features only detectable by MR imaging and not by plain radiographs or bone scans. From the present two cases, we found that a negative plain radiograph of the spine or a negative bone scan could not exclude skeletal metastases from myxoid liposarcoma, and MRI was a more sensitive screening procedure for their detection, especially in T1-weighted images. Unusual radiological features of skeletal metastases from myxoid liposarcoma are not well documented and only a few cases have been previously reported. Our aim is to document two more patients exhibiting the unusual radiological features of skeletal metastases from myxoid liposarcoma to improve their early detection and management.

Radiologically and histologically mixed liposarcoma: a report of two biphasic cases

We report two cases of liposarcomas showing biphasic patterns, radiologically and histologically. The first case was a 52-year-old man with a 17 x 12 cm intramuscular tumor in the right thigh. MR imaging revealed a mass composed of two components: a fat component and another soft tissue component. Histological diagnosis revealed mixed-type liposarcoma consisting of well-differentiated and myxoid liposarcoma. The second case was a 62-year-old man with a 22 x 15 cm intramuscular tumor in the left calf. MR imaging showed a mass composed of fat and non-fat components. The histological diagnosis was well-differentiated and pleomorphic liposarcoma.

Myxoid liposarcoma confirmed by TLS/FUS-CHOP fusion transcripts

Described here is the use of detecting TLS/FUS-CHOP fusion transcripts to confirm the diagnosis of a myxoid liposarcoma by nested reverse transcription-polymerase chain reaction assay using archival formalin-fixed, paraffin-embedded tissues of a young man with a benign-looking myxoid tumor on his upper extremity, which is often misdiagnosed clinically or histopathologically as a benign tumor.

Solitary bone metastasis from myxoid liposarcoma

BACKGROUND

Extrapulmonary metastasis is more common in liposarcoma than in other soft tissue sarcomas. However, osseous metastases are rare.

CASE REPORT

We report the case of a 61-year-old woman with a solitary histologically proven bone metastasis of the right femur from primary myxoid liposarcoma of the left thigh. In September 2000 resection of the primary tumor was performed. Histology showed a high-grade liposarcoma with round cell differentiation. Postoperative radiotherapy with 60 Gy was performed. In a follow-up MRI examination 11 months after initial diagnosis, a suspicious formation in the marrow space of the right proximal femur was detected. CT-guided biopsy was performed and histology showed a metastasis from liposarcoma. PET examination confirmed the metastasis as solitary. Curettage of the metastasis was performed followed by radiotherapy with 60 Gy. The patient was without evidence of disease in the last follow-up.

CONCLUSIONS

No standard treatment exists for the management of solitary extrapulmonary metastases from soft tissue sarcoma. Interdisciplinary cooperation is advised and the therapy concept should be chosen individually.

Myxoid solitary fibrous tumour of the ischiorectal fossa

Myxoid solitary fibrous tumours are a rare morphological sub-type of the rare solitary fibrous tumours. This case report appears to be the first reported ischiorectal occurrence of this rare tumour.