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.

Can radiomics improve the prediction of metastatic relapse of myxoid/round cell liposarcomas?

OBJECTIVE: The strongest adverse prognostic factor in myxoid/round cell liposarcomas (MRC-LPS) is the presence of a round cell component above 5% within the tumor bulk. Its identification is underestimated on biopsies and in the neoadjuvant setting. The aim was to improve the prediction of patients' prognosis through a radiomics approach. METHODS: Thirty-five out of 89 patients with MRC-LPS managed at our sarcoma reference center from 2008 to 2017 were included in this IRB-approved retrospective study as they presented with a pre-treatment contrast-enhanced MRI (median age, 49 years old). Two radiologists reported usual conventional/semantic radiological variables. After signal intensity (SI) normalization, voxel size standardization of T2-WI, and whole tumor volume segmentation, 44 3D-radiomics features were extracted. Using least absolute shrinkage and selection operator penalized Cox regression on prefiltered features, a radiomics score based on 3 weighted radiomics features was generated. Four prognostic multivariate models for MRFS were compared using concordance index: (1) clinical model, (2) semantic radiological model, (3) radiomics model, and (4) radiomics + semantic radiological model. RESULTS: Twelve patients showed a metastatic relapse. The radiomics score included FOS_Skewness, GLRLM_LRHGE, and SHAPE_Volume and correlated with MRFS (hazard ratio = 19.37, p = 0.0009) and visual heterogeneity on T2-WI (p < 0.0001). A high score indicated a poorer prognosis. After adjustment, the best predictive performances were obtained with model (4) (concordance index = 0.937) and the lowest with model (1) (concordance index = 0.637). CONCLUSION: Adding selected radiomics features that quantify tumor heterogeneity and shape at baseline to a conventional radiological analysis improves prediction of MRC-LPS patients' prognosis. KEY POINTS: • Fourteen radiomics features quantifying shape and heterogeneity of myxoid/round cell liposarcomas on T2-WI were associated with metastatic relapse in univariate analysis. • A radiomics score based on 3 selected and weighted radiomics features was a strong and independent prognostic factor for metastatic relapse-free survival. • The best prediction of metastatic relapse-free survival for myxoid/round cell liposarcomas was achieved by combining the radiomics score to relevant radiological features.

Myxoid Liposarcoma Metastasizing to the Parotid Gland.

Localization of metastases into the parotid gland is a very uncommon event. Usually they arise from primary tumors located in the head and neck, mainly melanoma or epidermoid carcinoma of the skin, while other histotypes, from others anatomical districts, hardly have a metastatic spread to the parotid. Myxoid liposarcoma (MLS) is a rare malignant tumor of the soft tissue that mainly occurs in the extremities, representing the second most common subtype of liposarcoma. Although it is typical for liposarcomas to metastasize to the lungs, it is known that MLS can spread also to extra pulmonary sites. The authors report a case of myxoid liposarcoma of the left thigh in a 64-year-old man, with an unusual metastatic double presentation to the contralateral forearm first and to the parotid gland then. MLS with metastatic disease to the parotid gland is an extremely rare event with very few cases reported in the English literature.

Myxoid liposarcoma: local relapse and metastatic pattern in 43 patients.

BACKGROUND: Liposarcomas are the second most common type of soft tissue sarcomas, 30-50% of these are of myxoid subtype. The aim of this retrospective study was to analyze the local control rate, the metastatic pattern and survival of patients in a consecutive single-institution series. METHODS: From 1983 to 2015, 43 patients with myxoid liposarcoma of the extremities and trunk wall underwent resections. The margin was defined as R0 (wide) or R1 (marginal). Patients were followed for evidence of local recurrence or distant metastasis. Overall and recurrence-free survival was calculated. RESULTS: The mean age was 48.6 years. The lower extremity was involved in 40 cases, the mean tumour size was 12 cm. In 31 cases a wide and in 12 cases a marginal resection was performed. Grading was G1 in 14, G2 in 25 and G3 in 4 cases. Nine patient died in follow-up, 4 of them with metastatic disease, all nonpulmonary. 5-year local recurrence (LR) free survival was 82%. 4 (9.3%) patients developed LR (all R1). Overall survival (OS) was 81% after 5 and 72% after 10 years. In multivariate analysis age and Grading proved to be significant on OS. According to univariate analysis, only age over 48 years and distant metastasis had a significant impact on overall survival. CONCLUSIONS: Patients with myxoid liposarcomas have a good prognosis. Myxoid liposarcoma has a distinct pattern of nonpulmonary metastatic disease. Therefore, patients with high-risk extremity myxoid liposarcoma should undergo imaging studies of the chest, abdomen, spine and pelvis as part of their staging and follow-up examinations preferably with whole body MRI, or CT scans and MRI of the spine and pelvic region for detection of suspected metastatic disease.

Prognostic factors and outcome of Liposarcoma patients: a retrospective evaluation over 15 years.

BACKGROUND: Soft tissue sarcomas are rare entities with over 50 histological subtypes. Liposarcoma (LS) is the most common neoplasm in this group; it is a complex neoplasm that is divided into different histological subtypes. Different therapy options, such as surgical resection, radiation, and chemotherapy, are available. Depending on the subtype, location, status of the resection margins and metastatic status, different therapy options are used. Therefore, the aim of this study was to determine the prognostic factors influencing the survival of patients affected by LS with consideration for the grading, histological subtype, state of the resection margin, size, location, metastases and local recurrence in a retrospective, single-centre analysis over 15 years. METHODS: We included 133 patients (male/female = 67/66) in this study. We recorded the histologic subtype, grade, TNM classification, localization, biopsy technique, tumour margins, number of operations, complications, radiation and dose, chemotherapy, survival, recrudescence, metastases and follow-up. Survivorship analysis was performed. RESULTS: We detected 56 (43%; 95%-CI 34.6-51.6%) atypical LS cases, 21 (16.2%; 95%-CI 9.8-22.5) dedifferentiated LS cases, 40 (30.8%; 95%-CI 22.8-38.7) myxoid LS cases and 12 (9.2%; 95%-CI 4.3-14.2) pleomorphic LS cases. G1 was the most common grade, which was followed by G3. Negative margins (R0) were detected in 67 cases (53.6%; 95%-CI 44.9-62.3) after surgical resection. Local recurrence was detected in 23.6% of cases. The presence of metastases and dedifferentiated LS subtype as well as negative margins, grade and tumour size are significant prognostic factors of the survival rates (p < 0.015). CONCLUSION: Grading, LS subtype, negative margins after surgery, metastases and tumour size are independently associated with disease-specific survival, and patients with local recurrence had lower survival rates. We hope our investigation may facilitate a further prospective study and clinical decision-making in LS.

Extensive left ventricular, pulmonary artery, and pericardial metastasis from myxoid liposarcoma 16 years after the initial detection of the primary tumour: a case report and review of the literature.

Liposarcoma is regarded as the second most common soft tissue malignant tumour. Metastasis of liposarcoma to the heart is very rare, and to date, less than 40 cases have been reported in the literature. We report a 46 year-old male with myxoid liposarcoma of the lower extremity who developed extensive metastasis to the left ventricle, pulmonary artery, and pericardium. The patient presented with acute symptoms of dyspnea 16 years after surgical resection of the primary tumour, and his dyspnea progressed to cardio-respiratory arrest within the first few days of hospital admission.

Establishment and characterization of a new human myxoid liposarcoma cell line (DL-221) with the FUS-DDIT3 translocation.

Myxoid liposarcoma has the pathognomonic fusion oncogene FUS-DDIT3 encoding a chimeric transcription factor. Metastatic risk is higher with an increased round cell component and has been linked to aberrations involving the IGFR/PI3K/AKT pathway. These molecular insights have yet to translate to targeted therapies, and the lack of experimental models is a major hindrance. We describe the initial in-depth characterization of a new cell line (DL-221) and establishment of a mouse xenograft model. The cell line DL-221 was derived from a metastatic pleural lesion showing myxoid and round cell histology. This newly established cell line was characterized for phenotypic properties and molecular cytogenetic profile, using PCR, COBRA-FISH, and western blot. Next-generation whole-exome sequencing was performed to further characterize the cell line and the parent tumor. NOD-SCID-IL2R gamma knockout mice were xenograft hosts. DL-221 cells grew an adhering monolayer and COBRA-FISH showed an aneuploid karyotype with t(12;16)(q13;p11) and several other rearrangements; RT-PCR demonstrated a FUS-DDIT3 fusion transcript type 1. Both the cell line and the original tumor harbored a TP53 compound heterozygous mutation in exon 4 and 7, and were wild-type for PIK3CA. Moreover, among the 1254 variants called by whole-exome sequencing, there was 77% concordance between the cell line and parent tumor. The recently described hotspot mutation in the TERT promoter region in myxoid liposarcomas was also found at C228T in DL-221. Xenografts suitable for additional preclinical studies were successfully established in mice after subcutaneous injection. The established DL-221 cell line is the only published available myxoid liposarcoma cell line that underwent spontaneous immortalization, without requiring SV40 transformation. The cell line and its xenograft model are unique and helpful tools to study the biology and novel potential-targeted treatment approaches for myxoid liposarcoma.

Round cell liposarcoma metastatic to the heart.

Myxoid liposarcoma is a soft tissue tumor in adults with rare cardiac involvement. We report a 50-year-old female with high grade round cell liposarcoma of the left knee with metastases to the right heart chambers. The tumor was located in the right atrium with extension to right ventricle. The Patient underwent radiotherapy after surgical resection and 12-month follow-up revealed no recurrent cardiac disease.

Myxoid\round cell liposarcoma (MRCLS) revisited: an analysis of 418 primarily managed cases.

BACKGROUND: Objectives of this study were to evaluate oncologic outcomes and to provide guidelines for the management of primary myxoid (MLS) and round cell liposarcoma (RCLS). METHODS: A multicenter, retrospective study of 418 cases of MRCLS primarily managed by Canadian multidisciplinary sarcoma teams. RESULTS: Study included 418 cases (MLS: 311 patients and RCLS: 107; >5% round cell) with a median age of 45 years and a median follow-up of 5.2 years. Median tumor size was 10 cm, and 81% were deep and 90% were in lower limb. The majority of patients underwent surgical resection and radiotherapy, with a small percentage (6%) receiving chemotherapy. The overall 10-year local control rate was 93% with no differences between MLS and RCLS. Radiotherapy was significant in preventing local relapse and reducing tumor diameter (median=18%) and improving microscopic margin status, but did not impact survival. Radiotherapy and the margin status were independent predictors of local recurrence. The 5- and 10-year metastatic-free survivals were 84 and 77% respectively for MLS and 69 and 46% for RCLS. The initial site of metastasis was found in multiple locations (34%) and bone involvement was frequent (40%) with predilection for spine (79%). Round cell percent (>5%) and tumor diameter (>10 cm) correlated with increased risk for metastasis and death. CONCLUSIONS: MLS and RCLS showed different metastatic risk but equally good local control. Radiotherapy was effective in preventing local recurrence and should be delivered as neoadjuvant. New staging strategies are to be defined to account for the unusual metastatic pattern.

The first case report of a metastatic myxoid liposarcoma invading the left atrial cavity and pulmonary vein.

Myxoid liposarcoma (MLS) is the most commonly encountered liposarcoma subgroup, accounting for about 50% of all cases. Metastatic MLS of the heart is extremely rare. Herein we describe for the first time metastasis of MLS to the left atrium and left upper pulmonary vein in a 54-year-old woman who was admitted with shortness of breath and cough persisting for 2 weeks. The patient reported that a total surgical excision of MLS of the left thigh followed by radiotherapy was performed 4 years ago. An emergency operation was performed due to rapidly progressive worsening of clinical condition and echocardiographic determination of left atrial mass protruding into the left ventricle and obstructing the mitral inflow throughout the diastole. The mass could not be totally excised because it was tightly adhered to the surrounding tissue. Postoperative magnetic resonance imaging (MRI) showed a 5 × 3 cm residual tumor deforming the posterior wall of the left atrium entirely and extending into the left upper pulmonary vein. Histopathological examination was consistent with MLS. In conclusion, considering probable cardiac metastasis in patients presenting with respiratory symptoms with medical history of soft tissue sarcomas would be life saving. The case is discussed, and a review of the literature in relation to the metastatic involvement of the heart by MLS is presented.

Clinicopathologic prognostic factors of pure myxoid liposarcoma of the extremities and trunk wall.

BACKGROUND: Myxoid liposarcoma is generally considered a low grade tumor but the presence of areas of round cells exceeding 5% is reportedly associated with a worse prognosis. Whether "pure" tumors without round cells are low grade has not been confirmed. While radiotherapy has been used for patients' myxoid liposarcoma it is unclear whether it reduces local recurrences. QUESTIONS/PURPOSES: We therefore determined the survival, roles of radiotherapy for local control, and prognostic factors of pure myxoid liposarcoma of the extremities and trunk wall. METHODS: We retrospectively reviewed 53 patients histologically diagnosed with pure myxoid liposarcoma arising in extremities and the trunk wall. Nine patients of the 53 received radiotherapy for primary tumors. Clinical features and prognosis was determined, and various factors were analyzed as to their usefulness as prognostic factors (age, gender, location, size, depth, surgical margin, and adjuvant radiotherapy). The minimum followup was 12 months (mean, 60 months; range, 12-226 months). RESULTS: Seven (13%) and 6 (11%) patients developed a local recurrence and distant metastasis, respectively. The 5- and 10-year disease-specific and disease-free survival rates were 90% and 83% and 77% and 77%, respectively. Radiotherapy had no impact on either overall or disease free survival. Age (older than 60 years) independently predicted worse overall and disease-free survival. CONCLUSIONS: In pure myxoid liposarcoma located in the extremities and trunk wall, relatively few patients developed distant metastasis suggesting the tumor is generally low grade. Local control could be achieved with wide surgical margins without radiotherapy. Age was associated with lower survival but size and depth were not. Myxoid liposarcoma in older patients requires special consideration for treatment and followup.

Clinical outcomes of patients with advanced synovial sarcoma or myxoid/round cell liposarcoma treated at major cancer centers in the United States.

BACKGROUND: Outcomes data regarding advanced synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) are limited, consisting primarily of retrospective series and post hoc analyses of clinical trials. METHODS: In this multi-center retrospective study, data were abstracted from the medical records of 350 patients from nine sarcoma centers throughout the United States and combined into a registry. Patients with advanced/unresectable or metastatic SS (n = 249) or MRCL (n = 101) who received first-line systemic anticancer therapy and had records of tumor imaging were included. Overall survival (OS), time to next treatment, time to distant metastasis, and progression-free survival (PFS) were evaluated using the Kaplan-Meier method and Cox regression. RESULTS: At start of first-line systemic anticancer therapy, 92.4% of patients with SS and 91.1% of patients with MRCL had metastatic lesions. However, 74.7% of patients with SS and 72.3% of patients with MRCL had ≥2 lines of systemic therapy. Median OS and median PFS from first-line therapy for SS was 24.7 months (95% CI, 20.9-29.4) and 7.5 months, respectively (95% CI, 6.4-8.4). Median OS and median PFS from start of first-line therapy for MRCL was 29.9 months (95% CI, 27-44.6) and 8.9 months (95% CI 4.5-12.0). CONCLUSIONS: To the best of our knowledge, this is the largest retrospective study of patients with SS and MRCL. It provides an analysis of real-world clinical outcomes among patients treated at major sarcoma cancer centers and could inform treatment decisions and design of clinical trials. In general, the survival outcomes for this selected population appear more favorable than in published literature.

Surgical treatment for epicardial metastasis of myxoid liposarcoma involving atrioventricular sulcus.

We report the case of a 52-year-old man who presented with a cardiac metastasis of myxoid liposarcoma invading the atrioventricular sulcus. The tumor was arising from the anterior wall of the right atrium and basal right ventricle. After complete resection of the tumor (14 x 7.5 x 6 cm, 279 g), the annulus had no strong supporting tissue because of invasion of the atrioventricular sulcus. The tricuspid valve was reconstructed with reinforcement of the annulus using an autologous pericardial strip. The defect of the right atrial wall was reconstructed with a pericardial patch. After the reconstruction, echocardiography showed grade 1 tricuspid regurgitation. Although the patient had a small metastasis to the lung after surgery, he is doing well after 31-month follow-up. We believe that it is justified to perform aggressive resection with annuloplasty, when it is feasible, for cardiac metastasis of myxoid liposarcoma.

Excellent local control rates and distinctive patterns of failure in myxoid liposarcoma treated with conservation surgery and radiotherapy.

PURPOSE: To evaluate the local control rates and patterns of metastatic relapse in patients with localized myxoid liposarcoma treated with conservation surgery and radiotherapy (RT). PATIENTS AND METHODS: Between 1960 and 2003, 127 patients with non-metastatic myxoid liposarcoma were treated with conservation surgery and RT at our institution. The median patient age was 39 years (range, 14-79 years). Of the 127 patients, 46% underwent preoperative RT (median dose, 50 Gy) and 54% underwent postoperative RT (median dose, 60 Gy). Also, 28% received doxorubicin-based chemotherapy as a part of their treatment. RESULTS: The median follow-up was 9.1 years. The overall survival rate at 5 and 10 years was 87% and 79%, respectively. The corresponding disease-free survival rates were 81% and 73%. The local control rate at > or =5 years was 97%. The actuarial rate of distant metastases at 5 and 10 years was 15% and 24%, respectively. Of the 27 patients who developed distant metastases, 48% did so in the retroperitoneum, 22% in other extrapulmonary soft tissues, 22% in the lung, 15% in bone, and 4% in the liver. CONCLUSION: The results of our study have shown that RT and conservation surgery for localized myxoid liposarcoma provide excellent local control. Distant metastatic relapse tended to occur in the retroperitoneum and other nonpulmonary soft tissues. Therefore, staging and surveillance imaging should include the abdomen and pelvis, as well as the thorax, for patients with localized myxoid liposarcoma.

Isolated metastatic extremity liposarcoma to the liver, an uncommon and transient finding.

BACKGROUND: Extremity liposarcomas can metastasize to different areas of the body but have rarely been demonstrated to metastasize to the liver. Due to the unusual occurrence of isolated metastatic extremity liposarcoma to the liver, the optimal treatment of this condition is unknown. CASE PRESENTATION: Less than one year after resection of a myxoid/round cell liposarcoma of the left lateral calf, a 61-year-old male presented with a CT scan showing a 2 cm low-density lesion in the right lobe of the liver. The lesion tripled in size over the next few months. An extensive evaluation revealed isolated disease to the liver. The lesion was surgically removed with a right hepatic lobectomy and the pathology was consistent with metastatic myxoid/round cell liposarcoma. CONCLUSION: Although extremity liposarcoma rarely metastasizes solely to the liver, the best chance at cure is with complete resection. Unfortunately, cure rates are very low in the setting of metastatic disease. As expected, the patient experienced progression of disease at sites outside of the liver 5 months after the liver resection.

Myxoid Liposarcoma: Prognostic Factors and Metastatic Pattern in a Series of 148 Patients Treated at a Single Institution.

OBJECTIVES: The authors reported a retrospective study on myxoid liposarcomas (MLs), evaluating factors that may influence overall survival (OS), local recurrence-free survival (LRFS), metastasis-free survival (MFS), and analyzing the metastatic pattern. METHODS: 148 MLs were analyzed. The sites of metastases were investigated. RESULTS: Margins (p = 0.002), grading (p = 0,0479), and metastasis (p < 0,0001) were significant risk factors affecting overall survival (OS). Type of presentation (p = 0.0243), grading (p = 0,0055), margin (p = 0.0001), and local recurrence (0.0437) were risk factors on metastasis-free survival (MFS). Authors did not observe statistically significant risk factors for local recurrence-free survival (LRFS) and reported 55% extrapulmonary metastases and 45% pulmonary metastases. CONCLUSION: Margins, grading, presentation, local recurrence, and metastasis were prognostic factors. Extrapulmonary metastases were more frequent in myxoid liposarcoma.

Fine-needle aspiration biopsy of myxoid liposarcoma metastatic to the liver: cytomorphologic and cytogenetic features.

Myxoid liposarcoma has characteristic cytomorphological features and carries a specific cytogenetic abnormality. Here we describe a case of myxoid liposarcoma metastatic to the liver, which was diagnosed by fine-needle aspiration biopsy. The aspirate smears revealed numerous oval to round tumor cells embedded in a myxoid background admixed with arborizing capillary vasculature. Some of the tumor cells showed adipocytic differentiation and a few lipoblasts were present. A fluorescence in situ hybridization analysis using CHOP break apart probe 12q13 demonstrated the presence of chromosomal translocation involving the CHOP gene, confirming the diagnosis. The case illustrates that cytomorphological evaluation with a targeted cytogenetic study can render a definite diagnosis of myxoid liposarcoma via fine-needle aspiration biopsy.

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.

Myxoid liposarcoma metastatic to the thyroid gland: a case report and literature review.

We present the second reported case of a myxoid liposarcoma metastatic to the thyroid gland in a 51-year-old gentleman with previous liposarcoma of the right thigh. Myxoid liposarcoma has a relatively good prognosis but tends to recur locally. Metastases affecting the thyroid gland are a rare entity and most commonly arise from the kidney, lung or breast. Clinical presentation, patterns of recurrence and prognosis of myxoid liposarcoma and metastases to the thyroid gland are discussed.