Pleomorphic Liposarcoma Research Articles

Intracranial pleomorphic liposarcoma misclassified as a pleomorphic xanthoastrocytoma by a DNA methylation classifier: illustrative case.

Recently, it has been shown that DNA methylation arrays and German Cancer Research Center (Deutsches Krebsforschungszentrum) methylation classifiers are useful aids in brain tumor diagnosis for cases in which histopathological diagnosis is difficult. However, not enough is known about diagnostic aids for intracranial liposarcoma (LPS). An 18-year-old woman with a history of natural killer/T-cell lymphoma, which had been treated with a bone marrow transplant and total body irradiation at age 11 years, presented with diplopia. Magnetic resonance imaging revealed a brain tumor in the posterior left temporal lobe, which was removed by craniotomy. The tumor was initially diagnosed as pleomorphic xanthoastrocytoma through histopathological and DNA methylation examination. She also had a soft tissue tumor in her left thigh, which was removed. It contained spindle cells with oval nuclei and highly pleomorphic cells and was diagnosed as radiation-induced LPS. Histopathological re-examination of the brain tumor led to a final diagnosis of pleomorphic LPS. In this report, the authors describe the case of a patient with an intracranial pleomorphic LPS that was initially classified as a pleomorphic xanthoastrocytoma by a DNA methylation classifier. Although DNA methylation classifiers are useful as diagnostic aids in cases in which definitive pathology is difficult to determine, there is a risk of misdiagnosis in some types of tumors. https://thejns.org/doi/10.3171/CASE24465.

Lipomatous Neoplasms of Soft Tissue: A Contemporary Review.

This review summarizes the clinicopathologic features of various lipomatous tumors of soft tissue and addresses some recent conceptual issues relating to adipocytic neoplasms, such as atypical spindle cell/pleomorphic lipomatous tumor and myxoid pleomorphic liposarcoma, and provides an update on the molecular aspects of these tumors. Recent advances in cytogenetic characterization and classification of lipomatous tumors are reviewed, and the genetic importance of distinct chromosomal aberrations are briefly discussed.

Pleomorphic Liposarcoma of the Extremity and Trunk: Multimodality Therapy for Some but Not All?

Pleomorphic liposarcoma (PLPS) is an ultra-rare malignancy distinct from well-differentiated/dedifferentiated and myxoid liposarcoma. In this study, we sought to (1) assess outcomes after surgery for primary, non-metastatic PLPS and (2) explore potential indications for multimodality therapy. Clinicopathologic data were retrospectively collected for patients treated from 2002 to 2019 at our sarcoma referral center. Descriptive data were summarized and Kaplan-Meier plots were constructed for overall survival (OS) and crude cumulative incidences (CCI) of disease-specific death (DSD), local recurrence (LR), and distant metastasis (DM). Univariable models were performed to assess the association of specific variables of interest on outcome. Forty-four pathology-verified PLPS cases were included in this study. Median tumor size was 8.5 cm; 75% were FNCLCC Grade 3. All patients underwent complete resection, including 15 patients (34%) who required re-excision to secure microscopic negative margins. Radiation therapy was given to 75% of patients, chemotherapy in 36%. At 5 years, OS was 75.3%; CCI of DSD, LR, and DM were 17.5%, 2.3%, and 32.5%. Larger tumor size was strongly associated with worse OS (p = 0.028) and DSD (p ≤ 0.001). A subgroup of patients (n = 10, 23%) with smaller, predominantly Grade 2 tumors underwent surgery alone without any LR or DM event at a median follow-up of 7.9 years. In PLPS, aggressive surgery and when appropriate, radiation therapy, results in excellent local control. Chemotherapy can be considered for larger tumors. Patients with smaller, Grade 2 tumors may be potentially cured with surgery alone.

Myxoid pleomorphic liposarcoma.

Myxoid pleomorphic liposarcoma (MPL) is an extremely rare adipocytic tumor, recently recognized as a distinct entity in the 5th edition of the World Health Organization (WHO) Classification of Soft Tissue and Bone Tumors. Predominantly found in the mediastinum of young women, MPLs exhibit a combination of histological features characteristic of myxoid liposarcoma and pleomorphic (lipo)sarcoma. Their unique molecular features distinguish MPLs from other liposarcomas. Unlike myxoid liposarcomas and well-differentiated/dedifferentiated liposarcomas, MPLs lack specific FUS/EWSR1::DDIT3 gene fusions and MDM2/CDK4 gene amplifications, respectively. MPLs are associated with complex karyotypes, further highlighting their distinct genetic profile. They demonstrate aggressive growth patterns, high recurrence rates, and a high tendency to metastasize. These factors contribute to a poor prognosis, with a median survival of approximately 22.6 months. The aim of this review article is to provide a comprehensive summary of previously documented case reports and studies related to MPLs. By shedding light on the intricate details of MPLs, researchers and clinicians can gain valuable insights that may pave the way for improvements in diagnosis, treatment, and patient outcomes in the future.

Synchronous occurrence of Retroperitoneal Pleomorphic Liposarcoma and Papillary thyroid carcinoma: A Rare Case Report

Synchronous occurrence of Retroperitoneal Pleomorphic Liposarcoma and Papillary thyroid carcinoma: A Rare Case Report

Pleomorphic Liposarcoma Cytologically Detected in Hemosiderotic Pleural Effusion: Pitfalls Mitigated by Cytologic Clues and Cellblock Immunocytochemistry.

Sarcomatous serous effusions are uncommon and diagnostically challenging. Dedifferentiated and pleomorphic liposarcomas are rare tumors in pleural effusions revealing highly pleomorphic tumor cells mimicking carcinoma, mesothelioma, melanoma, and other sarcomas. Hematothoracic effusions further complicate the cytologic diagnosis. Correct cytologic recognition is important. We report pleomorphic liposarcoma cytologically detected in effusion fluid in a 56-year-old man who presented with a massive unilateral pleural effusion. ThinPrep showed hemorrhagic effusion fluid characterized by lysed red blood cells, foamy macrophages, and siderophages intermixed with highly pleomorphic predominantly naked mononuclear and giant nuclei. The aggregated siderophages and vacuolated macrophages could be mistaken for tumor cells, whereas the bare nuclei may be missed as nonspecific degenerate changes. Cellblock sections showed highly pleomorphic mononuclear and multinucleated giant tumor cells with diagnostic lipoblasts, intermixed with foamy macrophages and siderophages. Cellblock immunocytochemistry showed staining for vimentin and S-100 protein in the tumor cells. Other lineage-specific immunomarkers were negative. CD68 and calretinin revealed frequent background macrophages and scarce mesothelial cells. The tumor cells were negative for MDM2 and CDK4. The entertained cytopathologic diagnosis was pleomorphic liposarcoma. Core needle biopsy was procured from the mass. The histopathologic features and immunoprofile of the tissue specimen matched the cytopathologic and immunocytochemical findings confirming the cytologic diagnosis of pleomorphic liposarcoma. Pleomorphic liposarcoma is an unexpected cytologically challenging finding in effusions, particularly when compounded by pitfalls introduced by hemosiderotic fluid. Attention to certain cytologic clues mitigate pitfalls. Cellblock is a valuable diagnostic tool when integrated with relevant negative and positive immunocytochemical markers.

Surufatinib plus toripalimab in advanced soft tissue sarcoma (STS): Results from a multicenter, single-arm, basket study.

42 Background: Soft tissue sarcomas (STS) are highly malignant despite their low incidence and prone to recurrence, with limited therapeutic options after failure of first-line treatment. Several antiangiogenic monotherapies have shown some efficacy but limited benefit. The open-label, multi-cohort, single-arm, basket study was performed to evaluate the efficacy and safety of the combination of surufatinib (a small-molecule inhibitor of VEGFR 1-3, FGFR1 and CSF-1R) with toripalimab (an anti-programmed death 1 [PD-1] antibody) for Chinese patients (pts) with advanced solid tumors. Here, we reported the results from the STS cohort. Methods: Pts with STS who had progressed on ≤ 2 lines of systemic chemotherapy, or were intolerant to standard treatment, or for whom there was currently no effective therapy were eligible. They received 21-day cycles of surufatinib 250 mg orally, once daily, plus toripalimab 240 mg intravenously, once every 3 weeks, until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) per RECIST 1.1. Results: As of data cutoff (Feb 28, 2023), a total of 20 pts (incl. 4 treatment-naïve pts) were enrolled and received the combination treatment (mean duration: 5.81 months [m]). Median (range) age was 50 (23-74) years, 10 pts were male, 17 pts were TNM stage IV. The pathological types include leiomyosarcoma (n=4, incl. 1 naïve patient), synovial sarcoma (n=4), alveolar soft part sarcoma (n=3, incl. 2 naïve pts), undifferentiated pleomorphic sarcoma (n=3), liposarcoma (n=2, incl. 1 naïve patient) and fibrosarcoma (n=1), malignant fibrous histiocytoma (n=1) and others (n=2). Seven (35%) pts had PD-L1 combined positive score of ≥1. The median follow-up duration was 27.14 m. Confirmed ORR and disease control rate (DCR) for 19 efficacy-evaluable pts was 10.5% and 68.4%, respectively; median duration of response was 7.05m. The median progression-free survival (mPFS) and median overall survival (mOS) was 2.69 m and 16.23 m for all dosed pts. For 16 previously treated pts, ORR and DCR was 6.3% and 62.5% respectively; median duration of response (DoR) was 7.13 m; mPFS was 2.65 m; mOS was 14.32 m. 18 (90%) pts experienced at least one treatment-related adverse event (TRAE), and 7 (35%) of them reported grade ≥3 TRAEs. The incidence of immune-related adverse events (irAEs) was 70%, only 2 pts had grade ≥3 irAEs, which were immune-related pancreatitis and immune-related diabetes. 2 pts were permanently discontinued due to TRAEs, which were grade 2 renal impairment and grade 3 hyperglycemia. No new safety signals were observed. Conclusions: Surufatinib plus toripalimab had a promising antitumor activity and a manageable safety profile in pts with advanced STS. Clinical trial information: NCT04169672 .

Cureit: An End-to-End Pipeline for Implementing Mixture Cure Models With an Application to Liposarcoma Data.

Cure models are a useful alternative to Cox proportional hazards models in oncology studies when there is a subpopulation of patients who will not experience the event of interest. Although software is available to fit cure models, there are limited tools to evaluate, report, and visualize model results. This article introduces the cureit R package, an end-to-end pipeline for building mixture cure models, and demonstrates its use in a data set of patients with primary extremity and truncal liposarcoma. To assess associations between liposarcoma histologic subtypes and disease-specific death (DSD) in patients treated at Memorial Sloan Kettering Cancer Center between July 1982 and September 2017, mixture cure models were fit and evaluated using the cureit package. Liposarcoma histologic subtypes were defined as well-differentiated, dedifferentiated, myxoid, round cell, and pleomorphic. All other analyzed liposarcoma histologic subtypes were significantly associated with higher DSD in cure models compared with well-differentiated. In multivariable models, myxoid (odds ratio [OR], 6.25 [95% CI, 1.32 to 29.6]) and round cell (OR, 16.2 [95% CI, 2.80 to 93.2]) liposarcoma had higher incidences of DSD compared with well-differentiated patients. By contrast, dedifferentiated liposarcoma was associated with the latency of DSD (hazard ratio, 10.6 [95% CI, 1.48 to 75.9]). Pleomorphic liposarcomas had significantly higher risk in both incidence and the latency of DSD (P < .0001). Brier scores indicated comparable predictive accuracy between cure and Cox models. We developed the cureit pipeline to fit and evaluate mixture cure models and demonstrated its clinical utility in the liposarcoma disease setting, shedding insights on the subtype-specific associations with incidence and/or latency.

Analysis of MDM2 and TP53 genes in canine liposarcoma

Canine liposarcoma is an uncommon tumor that shares morphological similarities with its human counterpart. In dogs, the genetic features of this tumor are unknown and, based on immunohistochemical studies, amplification of the gene MDM2 and the mutation of TP53 are suspected. In this study 51 cases of primary liposarcomas were immunohistochemically stained for MDM2 and p53 and subjected to fluorescent in situ hybridization and next-generation sequencing to detect MDM2 amplification and TP53 mutations, respectively. MDM2 and p53 were expressed in 21 and 6 cases, respectively. MDM2 amplification and TP53 mutations were identified in 10 and 15 cases, respectively. Statistical analysis revealed an association of the myxoid subtype and the mitotic count with p53 expression and TP53 mutation. No association was found between MDM2 amplification and MDM2 expression or tumor subtype. These results suggest that despite morphological similarities, canine liposarcoma differs from its human counterpart, for which MDM2 amplification is diagnostic for well differentiated and de-differentiated variants, and TP53 mutations are more common in pleomorphic liposarcoma rather than the myxoid one as occur in our cases. Furthermore, canine myxoid liposarcoma likely represents a distinct disease rather than a mere morphological variant.

Pleomorphic Liposarcoma Unraveled: Investigating Histopathological and Immunohistochemical Markers for Tailored Diagnosis and Therapeutic Innovations.

Liposarcomas are some of the most challenging soft tissue tumors and are subclassified into multiple subtypes with special histologic and molecular features. The peculiarities of each histopathological subtype influence the clinical behavior, management, and treatment of these neoplasms. For instance, well-differentiated liposarcomas are common soft tissue malignancies and usually display a favorable outcome. On the other hand, pleomorphic liposarcoma is the rarest, yet the most aggressive subtype of liposarcoma. This histopathological diagnosis may be challenging due to the scarce available data and because pleomorphic liposarcomas can mimic other pleomorphic sarcomas or other neoplasms of dissimilar differentiation. Nevertheless, the correct diagnosis of pleomorphic liposarcoma is of utmost importance as such patients are prone to develop local recurrences and metastases. Treatment usually consists of surgical excision along with radiotherapy and follow-up of the patients. Therefore, this review aims to assess the complex clinical, histological, and immunohistochemical features of liposarcomas in order to establish how these characteristics influence the management and prognosis of the patients, emphasizing the particularities of pleomorphic liposarcoma.

An overview on liposarcoma subtypes: Genetic alterations and recent advances in therapeutic strategies.

Liposarcoma (LPS) is a rare malignancy of adipocytic differentiation. According to World Health Organization classification, LPS comprises of four principle subtypes Atypical lipomatous tumor/Well-differentiated liposarcoma (ATL/WDLPS), Dedifferentiated liposarcoma (WDLPS), Myxoid liposarcoma (MLPS), and Pleomorphic liposarcoma (PLPS). Each subtype can develop at any location and shows distinct clinical behavior and treatment sensitivity. ATL/ WDLPS subtype has a higher incidence rate, low recurrence, and is insensitive to radiation and chemotherapy. DDLPS is the focal progression of WDLPS, which is aggressive and highly metastasizing. MLPS is sensitive to radiation and chemotherapy, with a higher recurrence rate and metastasis. PLPS subtype is highly metastasizing, has a poor prognosis, and exhibiting higher recurrence rate. Initial histological analysis provides information for the characterization of LPS subtypes', further molecular and genetic analysis provides certain subtype specifications, such as gene amplifications and gene fusions. Such molecular genetic alterations will be useful as therapeutic targets in various cancers, including the LPS subtypes. A wide range of novel therapeutic agents based on genetic alterations that aim to target LPS subtypes specifically are under investigation. This review summarizes the LPS subtype classification, their molecular genetic characteristics, and the implications of genetic alterations in therapeutics.

Genomic profiling of pleomorphic rhabdomyosarcoma reveals a genomic signature distinct from that of embryonal rhabdomyosarcoma.

Pleomorphic rhabdomyosarcoma (PRMS) is a rare and highly aggressive sarcoma, occurring mostly in the deep soft tissues of middle-aged adults and showing a variable degree of skeletal muscle differentiation. The diagnosis is challenging as pathologic features overlap with embryonal rhabdomyosarcoma (ERMS), malignant Triton tumor, and other pleomorphic sarcomas. As recurrent genetic alterations underlying PRMS have not been described to date, ancillary molecular diagnostic testing is not useful in subclassification. Herein, we perform genomic profiling of a well-characterized cohort of 14 PRMS, compared to a control group of 23 ERMS and other pleomorphic sarcomas (undifferentiated pleomorphic sarcoma and pleomorphic liposarcoma) using clinically validated DNA-targeted Next generation sequencing (NGS) panels (MSK-IMPACT). The PRMS cohort included eight males and six females, with a median age of 53 years (range 31-76 years). Despite similar tumor mutation burdens, the genomic landscape of PRMS, with a high frequency of TP53 (79%) and RB1 (43%) alterations, stood in stark contrast to ERMS, with 4% and 0%, respectively. CDKN2A deletions were more common in PRMS (43%), compared to ERMS (13%). In contrast, ERMS harbored somatic driver mutations in the RAS pathway and loss of function mutations in BCOR, which were absent in PRMS. Copy number variations in PRMS showed multiple chromosomal arm-level changes, most commonly gains of chr17p and chr22q and loss of chr6q. Notably, gain of chr8, commonly seen in ERMS (61%) was conspicuously absent in PRMS. The genomic profiles of other pleomorphic sarcomas were overall analogous to PRMS, showing shared alterations in TP53, RB1, and CDKN2A. Overall survival and progression-free survival of PRMS were significantly worse (p < 0.0005) than that of ERMS. Our findings revealed that the molecular landscape of PRMS aligns with other adult pleomorphic sarcomas and is distinct from that of ERMS. Thus, NGS assays may be applied in select challenging cases toward a refined classification. Finally, our data corroborate the inclusion of PRMS in the therapeutic bracket of pleomorphic sarcomas, given that their clinical outcomes are comparable.

Outcome of patients with liposarcoma: A retrospective review over 12 ​Years in a single center

BackgroundLiposarcoma is the most common soft tissue sarcoma, which comprises around 20% of soft tissue sarcoma. While diverse therapeutic approaches exist for liposarcoma, the primary goal remains the achievement of effective local disease control. Wide resection of liposarcoma is the cornerstone of treatment. Radiotherapy is often employed as an adjuvant measure to enhance the local disease control. At Hospital Kuala Lumpur, the treatment protocol includes R0 resection and followed by adjuvant radiotherapy. This study aims to review the demographic characteristic of liposarcoma patients and evaluate the efficacy of their treatment based on the treatment protocol. Method and materialThis is a retrospective cohort study. A total of 72 patients (male/female ​= ​43/29) were included in this study. Recorded parameters included the histologic subtype, tumor location, treatment modality, resection margin, radiotherapy status, and occurrences of local recurrence and metastasis. ResultHistopathological examination revealed a varied spectrum of liposarcoma subtypes, with the predominant subtype being atypical lipomatous tumor (n ​= ​35), followed by myxoid liposarcoma (n ​= ​32), two cases of dedifferentiated liposarcoma, and three cases of pleomorphic liposarcoma. Of these patients, 69 underwent resection, while three necessitated amputations. Total 62 achieving negative and 10 cases had R1 margins. Adjuvant radiotherapy was administered in 58 cases. Overall, the local recurrence was observed in only six cases. ConclusionThis study emphasizes that achieving R0 resection is the fundamental approach in the treatment of liposarcoma and is able to minimize the risk of local recurrence.

Multimodality therapy and innovative surgical techniques for successful resection and reconstruction of a rare and aggressive pleomorphic liposarcoma

Managing rare thoracic liposarcomas, accounting for < 1% of soft tissue sarcomas, demands tailored strategies. We explore effective approaches, considering tumor attributes and innovative techniques, and compare NCCN-guided therapies and surgeries. Using PubMed, Embase, and Cochrane Library, we identified studies on thoracic liposarcomas. Data synthesis summarized findings, acknowledging rarity's evidence limitations. This study reports a successful resection of a rare thoracic soft tissue sarcoma. Overcoming challenges through innovative techniques like hyperthermic pleural lavage and Gore-Tex® reconstruction, it underscores neoadjuvant therapies and surgical precision. Thoracic liposarcoma management demands tailored multidisciplinary approaches. Neoadjuvant chemotherapy, surgery, and adjuvant therapies are fundamental. Surgical ingenuity, like extrapleural pneumonectomy and novel reconstructions, ensures thorough tumor removal with minimal complications. Hyperthermic pleural lavage and Gore-Tex® offer promising refinements. Successful outcomes highlight potential for improved prognoses. Further research will optimize strategies for this rare, aggressive cancer.

Well-differentiated/dedifferentiated liposarcoma associated with myxoid-like morphology: a clinicopathological and molecular genetic characteristics analysis of 34 cases

Objective: To investigate the clinicopathological and molecular genetic characteristics of well-differentiated/dedifferentiated liposarcoma (WDLPS/DDLPS) with myxoid-like morphology, and to distinguish them from myxofibrosarcoma (MFS) with similar morphology. Methods: Twenty-nine cases of myxoid-like liposarcoma and 5 cases of MFS were collected from Henan Provincial People's Hospital, Zhengzhou, China and the First Medical Center of PLA General Hospital, Beijing, China from January 2015 to March 2023. Relevant markers were detected using immunohistochemistry and fluorescence in situ hybridization (FISH). The literature was also reviewed. Results: There were 24 males and 10 females, with ages ranging from 41 to 73 years. The tumor sites included retroperitoneum (n=17), abdomen (n=9), lower limbs (n=5), scrotum (n=1), upper limb (n=1) and axilla (n=1). WDLPS was commonly seen as lipomatoid type (12 cases), while the dedifferentiated components of DDLPS included low-grade (13 cases) and high-grade (2 cases) morphology, with low-high grade myxofibrosarcoma, dermatofibrosarcoma protuberans, and low-grade fibrosarcoma structures. Twenty-nine liposarcomas had various proportions of myxoid-like morphology, while 16 showed various degrees of tumor necrosis. The myxoid-like component showed myxoid pleomorphic liposarcoma (MLPS)-like morphology, lobulated growth, characteristic slender, ramified capillary network,"chicken claw-like"morphology, mucus-rich stroma and lung edema-like morphology. Tumor cells were spindle and oval, with many variable vacuolar lipoblasts. MDM2 gene amplification was detected using FISH and present in all tested cases (29/29). DDIT3 break-apart mutation was not detected, but its cluster amplification was present (24/29). Among the MFS cases, one showed cluster amplification (1/5), but no cases showed break-apart or amplification of MDM2 gene. Conclusions: WDLPS/DDLPS with myxoid-like morphology is most commonly seen in the retroperitoneum and abdominal cavity and mostly harbors DDIT3 break-apart probe amplification, while this amplification is not specific to liposarcoma. For core biopsy specimens or very rare tumors in the limbs, when histology has mucinous stroma and MLPS-like morphology, misdiagnosis of MLPS or other non-lipomatous neoplasms with myxoid morphology should be avoided.

A Case of Myxoid Pleomorphic Liposarcoma with Rhabdoid Cells: A Diagnostic Pitfall.

Myxoid pleomorphic liposarcoma (MPLS) is an extremely rare tumor listed in the fifth edition of the WHO classification (2020). Histologically, it mainly comprises a mixture of myxoid and pleomorphic liposarcoma-like components. Genetically, it lacks FUS/EWSR1::DDIT3 fusion and MDM2 amplification. Herein, we describe an example of MPLS with rhabdoid cells in a 10-year-old girl who presented with a growing mass in the right inguinal region. The specimen from the wide excision measured 68 mm × 55 mm × 43 mm, and a circumscribed and lobulated mass was observed in the subcutaneous tissue. Histologically, oval-to-short, spindle-shaped, proliferating tumor cells with moderate nuclear atypia and mesh-like capillaries against a myxoid background were noted. Adipocytes were observed focally, while rhabdoid cells were observed multifocally. Immunohistochemically, the tumor showed inconsistent reactivity for desmin but was negative for MYOD1, myogenin, MDM2, and CDK4. Fluorescence in situ hybridization revealed no DDIT3 rearrangement. Despite adjuvant chemotherapy, the tumor metastasized to the thoracic cavity 24 months after excision. The metastatic lesions contained abundant lipoblasts rather than rhabdoid cells, and we concluded this tumor was a MPLS. The presence of rhabdoid cells could be a diagnostic pitfall, and recognizing such a variation in histology would help improve diagnostic accuracy.

Genetically engineered mouse model of pleomorphic liposarcoma: Immunophenotyping and histologic characterization

IntroductionPleomorphic liposarcoma is a rare and aggressive subset of soft-tissue sarcomas with a high mortality burden. Local treatment largely consists of radiation therapy and wide surgical resection, but options for systemic therapy in the setting of metastatic disease are limited and largely ineffective, prompting exploration of novel therapeutic strategies and experimental models. As with other cancers, sarcoma cell lines and patient-derived xenograft models have been developed and used to characterize these tumors and identify therapeutic targets, but these models have inherent limitations. The establishment of genetically engineered mouse models represents a more realistic framework for reproducing clinically relevant conditions for studying pleomorphic liposarcoma. MethodsTrp53fl/fl/Rb1fl/fl/Ptenfl/fl (RPP) mice were used to reliably generate an immunocompetent model of mouse pleomorphic liposarcoma through Cre-mediated conditional silencing of the Trp53, Rb1, and Pten tumor suppressor genes. Evaluation of tumor-infiltrating lymphocytes was assessed with immunostaining for CD4, CD8, and PD-L1, and flow cytometry with analysis of CD45, CD3, CD4, CD8, CD19, F4/80, CD11b, and NKp46 sub-populations. ResultsMice reliably produced noticeable soft-tissue tumors in approximately 6 weeks with rapid tumor growth between 100 and 150 days of life, after which mice reached euthanasia criteria. Histologic features were consistent with pleomorphic liposarcoma, including widespread pleomorphic lipoblasts. Immunoprofiling and assessment of tumor-infiltrating lymphocytes was consistent with other soft-tissue sarcomas. ConclusionGenetically engineered RPP mice reliably produced soft-tissue tumors consistent with pleomorphic liposarcoma, which immunological findings similar to other soft-tissue sarcomas. This model may demonstrate utility in testing treatments for this rare disease, including immunomodulatory therapies.

Acquired isolated factor VII deficiency in a patient with myxoid pleomorphic liposarcoma, case report

Introduction: Acquired factor VII (FVII) deficiency is a rare condition with various causes, including acquired inhibitors to FVII, liver disease, and malignancies. Myxoid pleomorphic liposarcoma is a rare and aggressive form of soft tissue sarcoma that can cause a range of clinical manifestations, including bleeding and clotting disorders. Patient concerns and diagnosis: We present a case report of a 21-year-old man with severe acquired FVII deficiency due to mediastinal myxoid pleomorphic liposarcoma. The patient presented with elevated International normalized ratio (INR) and a severe reduction in FVII coagulant activity, unresponsive to conventional therapy. While an acquired inhibitor to FVII was initially suspected, negative results from laboratory testing, including protein G sepharose adsorption and a Bethesda assay using Immunoglobulin G purified from patient plasma, made the diagnosis of an acquired inhibitor to FVII uncertain. Interventions and outcome: The patient underwent surgical resection of the tumor, supported by recombinant FVII infusion, leading to the normalization of coagulation parameters. However, a relapse of the disease was detected 6 months later when he was noted to have a decline in FVII levels. Conclusion: This case highlights the importance of considering rare causes of bleeding and clotting disorders, particularly in unresponsive or atypical presentations. It also underscores the need for close monitoring and follow-up in patients with acquired FVII deficiency, even after successful treatment.

Pleomorphic liposarcoma of the extremity with solitary huge liver metastasis at initial diagnosis treated with conversion surgery combined with adjuvant chemotherapy: a case report

BackgroundPleomorphic liposarcoma is the rarest subtype of liposarcoma. Pleomorphic liposarcomas are generally unresponsive to chemotherapy and radiotherapy. Moreover, metastasis in the liver, as the first and sole site, from a primary extremity soft tissue sarcoma, including pleomorphic liposarcoma, is extremely rare. Information regarding the appropriate management of these lesions is limited.Case presentationA 50-year-old Japanese woman presented with a mass in the left thigh. Imaging examination revealed a soft tissue sarcoma on the left posterior thigh. The tumor was histologically diagnosed as pleomorphic liposarcoma. Computed tomography examination for assessment of metastases incidentally detected a huge liver mass. Wide excision of sarcoma was performed prior to chemotherapy. Right trisectionectomy was necessary to achieve hepatic clearance; however, the future liver remnant volume was insufficient. Therefore, we decided to administer anthracycline-based chemotheraphy to shrink the tumor. After seven courses of adriamycin-based chemotherapy, the liver tumor size was reduced from 211 mm × 106 mm × 180 mm to 105 mm × 66 mm × 90 mm. Finally, a right hemihepatectomy was performed. The patient was continuously monitored and was metastasis or local recurrence free within 5 months after liver surgery.ConclusionChemotherapy is effective in some cases for the treatment of unresectable liver metastases of pleomorphic liposarcoma, and complete resection is possible with conversion surgery. If the patient’s general condition permits, anthracycline-based chemotherapy can be used for the treatment of stage 4 pleomorphic liposarcoma.

PDE3A Is a Highly Expressed Therapy Target in Myxoid Liposarcoma.

Liposarcomas (LPSs) are a heterogeneous group of malignancies that arise from adipose tissue. Although LPSs are among the most common soft-tissue sarcoma subtypes, precision medicine treatments are not currently available. To discover LPS-subtype-specific therapy targets, we investigated RNA sequenced transcriptomes of 131 clinical LPS tissue samples and compared the data with a transcriptome database that contained 20,218 samples from 95 healthy tissues and 106 cancerous tissue types. The identified genes were referred to the NCATS BioPlanet library with Enrichr to analyze upregulated signaling pathways. PDE3A protein expression was investigated with immunohistochemistry in 181 LPS samples, and PDE3A and SLFN12 mRNA expression with RT-qPCR were investigated in 63 LPS samples. Immunoblotting and cell viability assays were used to study LPS cell lines and their sensitivity to PDE3A modulators. We identified 97, 247, and 37 subtype-specific, highly expressed genes in dedifferentiated, myxoid, and pleomorphic LPS subtypes, respectively. Signaling pathway analysis revealed a highly activated hedgehog signaling pathway in dedifferentiated LPS, phospholipase c mediated cascade and insulin signaling in myxoid LPS, and pathways associated with cell proliferation in pleomorphic LPS. We discovered a strong association between high PDE3A expression and myxoid LPS, particularly in high-grade tumors. Moreover, myxoid LPS samples showed elevated expression levels of SLFN12 mRNA. In addition, PDE3A- and SLFN12-coexpressing LPS cell lines SA4 and GOT3 were sensitive to PDE3A modulators. Our results indicate that PDE3A modulators are promising drugs to treat myxoid LPS. Further studies are required to develop these drugs for clinical use.