Well-differentiated Liposarcoma Research Articles

Primary Liposarcoma of the Spleen: Case Report With Review of the Literature.

We present a 55-year-old woman with a palpable mass in the right upper abdomen. Contrast-enhanced computed tomography showed a highly vascularized and primary resectable tumor of the spleen. We performed an open splenectomy with locoregional lymphadenectomy. Histopathological and immunohistochemical evaluation did not reveal classic markers of angiosarcoma, littoral cell angioma, or follicular dendritic cell sarcoma, but showed MDM2-amplification by FISH in all tumor cells as a marker for liposarcoma. The tumor showed growth limited to the spleen tissue. No MDM2-amplification was detectable in the perisplenic adipose tissue, so that infiltration of the spleen by retroperitoneal liposarcoma could be excluded. In summary, well-differentiated liposarcoma confined to the spleen was diagnosed. To the best of our knowledge, this is the first description of a primary liposarcoma of the spleen reported in the literature. Due to the local recurrence risk of liposarcomas, even after R0 resection, we recommended long-term periodic follow-up.

Perinephric Myxoid Pseudotumor of Fat: A Series of 13 Cases and Literature Review

Perinephric myxoid pseudotumor of fat (PMPF) is a recently described and rare retroperitoneal mass-forming lesion whose clinical significance chiefly involves mimicry of a variety of soft tissue tumors. For unknown reasons, it commonly occurs in male patients with underlying non-neoplastic renal diseases and/or type 2 diabetes (DMT2). A total of 55 cases have been reported in the literature. Recently, we have encountered 13 such masses with peculiar histologic features; thus, we sought to investigate our experience and review the clinicopathologic characteristics of the literature. Our series confirms that PMPF frequently occurs in adult male patients (11/13, 85%), with an average age of 66 years, and commonly co-occurs with renal disease, such as DMT2 (2/13, 15%), end-stage renal disease (ESRD) (5/13, 39%), renal cysts (4/13, 31%), concurrent or prior renal neoplasia (2/13; 15%), and myeloma/lymphoma (2/13; 15%). Histologic evaluation shows lipomatous masses commonly showing variable amounts of fat necrosis, myxoid degeneration, lymphoplasmacytic inflammation and lacking atypical hyperchromatic stromal spindle cells. Unusual histologic features include extramedullary hematopoiesis (1/13, 8%), hemosiderin deposition (4/13, 31%), and small wisps of mature smooth muscle (6/13, 46%). All cases tested were negative for MDM2 and did not show an increased ratio of IgG4+/IgG+ plasma cells. Our study confirms the clinical and pathologic features of PMPF and expands its histologic spectrum, underscoring the importance of this entity as a benign pseudotumor which should be included in the differential diagnosis of other fat-containing retroperitoneal masses, particularly well-differentiated liposarcoma.

Real-world Referral Pattern of Unplanned Excision in Patients With Soft-tissue Sarcoma: A Multicenter Study Conducted by the Bone and Soft-tissue Tumor Study Group of the Japan Clinical Oncology Group.

Despite the well-publicized clinical outcomes after unplanned excision (UE) and re-excision (re-excision) in patients with soft-tissue sarcoma (STS), there is little information about the real-life referral patterns for UE, such as patient profile, details of procedures, and subsequent management after UE. We aimed to investigate the characteristics of patients with UE who were referred to sarcoma-specific centers. Between May 2022 and June 2023, we registered 97 patients who underwent UE and were referred to sarcoma-specific centers in Japan. We excluded those with well-differentiated liposarcomas and dermatofibrosarcoma protuberances. We investigated the details of UE and additional treatment after UE. There were 49 men and 48 women, with a mean age of 62 years. A broad range of surgeons performed UE; 36 plastic surgeons, 22 orthopedic surgeons, 17 general surgeons, 17 dermatologists, and 5 others. The mean tumor size was 4.1 cm. Local anesthesia was administered to 58 patients. Forty-five patients underwent UE without prior magnetic resonance imaging. Inappropriate transverse skin incisions were performed in 42 patients. Of the 97 patients, 82 underwent re-excision after UE. The mean time between UE and date of initial presentation at the referral hospital was 46 days. The mean interval between UE and re-excision was 96 days. Of the 82 patients, 59 underwent soft-tissue reconstruction after re-excision. A broad range of surgeons performed UE. Continuous education about STS should be considered for all surgeons. UE should be avoided because residual tumors are common, and reconstructive surgery may be necessary.

Evaluation of morphological patterns and immunohistochemical characteristics of well-differentiated and dedifferentiated liposarcomas

Evaluation of morphological patterns and immunohistochemical characteristics of well-differentiated and dedifferentiated liposarcomas

MDM2 Testing In Lipomatous Tumors: An Institutional Experience with 1,161 Neoplasms

Abstract Introduction/Objective Amplifications of the MDM2 gene is a well-recognized central molecular event in atypical lipomatous tumors, well-differentiated liposarcomas, and dedifferentiated liposarcomas. However, given the fact that most adipocytic neoplasms are benign, the specific testing approaches that will maximize the detection of MDM2 amplified tumors in an accurate and cost-efficient manner remains unclear. The purpose of this study is to present our experience with MDM2 testing by FISH in a large cohort of lipomatous neoplasms. Methods/Case Report The pathologic database of an academic medical center was queried for all lipomatous tumors as well as all tumors for which MDM2 testing was performed during a three-year period. At our center, MDM2 testing for well differentiated adipocytic neoplasms is triggered by the so-called “traditional criteria”: a deep tumor and/or tumor size >10 cm and/or recurrence. We also take an expanded approach for a variety of indications that may include equivocal atypia or clinical/imaging concern, among others. Testing is also performed on overt malignancies for which dedifferentiated liposarcoma is a plausible consideration after review of morphologic features. Clinicopathologic data, including patient age of diagnosis, tumor size, depth of tumor, results from MDM2 testing [when performed], anatomic location(s) and recurrence [where applicable], were collected for each patient. Results (if a Case Study enter NA) 1161 cases were assessed, 456 of whom underwent MDM2 testing, and 108 of which were ultimately classified as MDM2 amplified. Standardized bivariable comparisons found that a deep tumor location (p=0.0014) and older age (p=0.0002), but not tumor size at the >10 cm cut off were associated with MDM2 positivity. However, a logistic regression model showed that neither size, depth or age were significantly associated with MDM2 positivity. Among the MDM2-positive cohort, 91% had tumor sizes <10 cm, 14% were superficial, 23% were non-recurrent and 15% were less than the median cohort patient age of 58 years. If the aforementioned “traditional criteria” were used as the sole basis for MDM2 testing, 50 (46.29%) of the 108 cases that were ultimately classified as MDM2 positive would not have been tested. Conclusion Our findings suggest that a strict adherence to “traditional criteria” may result in a significant subset of MDM2 positive tumors not being tested in lipomatous tumors. A more expansive approach that incorporates additional indications for testing, should be evaluated.

Variability in treatment approaches, outcomes, and recurrence patterns after curative intent treatment for primary retroperitoneal sarcomas in Latin America: A report on 333 patients from LATAMSARC collaborative working group

Background and objectiveRetroperitoneal sarcomas (RPS) are rare tumors with several well-defined histologic subtypes. This study aimed to assess the epidemiology, treatment patterns, and outcomes of patients with retroperitoneal sarcoma in Latin America and analyze patterns of recurrence and treatment variations in a large population of patients treated at reference centers. MethodsThis retrospective descriptive study utilized an electronic database of medical records from LATAMSARC (a group studying sarcomas consisting of different centers in various countries in Latin America, including Argentina, Chile, Costa Rica, Mexico, and Peru). Adult patients (≥18 years) with retroperitoneal sarcoma who underwent surgery at six cancer centers in Latin America were included. Key outcomes were practice patterns, overall survival (OS), and progression-free survival (PFS). ResultsIn this retrospective study, 333 patients diagnosed with retroperitoneal sarcomas met the inclusion/exclusion criteria. The cohort consisted of 157 females (42.3 %) and 176 males (57.7 %), with an average age of 53.9 years (SD 13.37). Histology most commonly included Dedifferentiated Liposarcoma (31.5 %), Well-Differentiated Liposarcoma (29.7 %), and Leiomyosarcoma (9.9 %). The tumors predominantly resided in the retroperitoneum (81.7 %) and showed a mean diameter of 23.53 cm (SD 13.8 cm). Surgical interventions varied, with Complete Compartmental Resection performed in 31.2 % of cases and Simple Complete Resection in 29.4 %. Postoperative complications were documented, with Clavien-Dindo Grade ≥3 complications occurring in 16.8 % of patients. An R0/1 resection was obtained in 91.6 % of cases. The ICU admission rate post-surgery was 18.6 %. Adjuvant treatments included radiotherapy in 8.1 %. Local recurrence occurred in 20.7 % of cases, with the majority being ipsilateral. Distal recurrence was observed in 15 patients, predominantly affecting the liver. The mean overall survival was 65.5 months, and disease-free survival was 47.0 months. ConclusionThis study provides information on the epidemiology, treatment patterns, and outcomes of retroperitoneal sarcomas in a group of reference centers in Latin America. These results represent Latin America's largest body of evidence on retroperitoneal sarcomas.

A rare well-differentiated renal retroperitoneal liposarcoma: a case report

Introduction and importance: Retroperitoneal liposarcomas (RPLPSs) are rare tumors that arise from mesenchymal cells in the peritoneum cavity. The sites of PRLPSs vary a lot, but renal PRLPSs are extremely rare (there are only 45 cases of Renal retroperitoneal liposarcomas on PubMed). In this case, the authors present a rare renal retroperitoneal liposarcoma case, describe the major concepts, and raise awareness about this rare tumor. Case presentation: A 44-year-old woman presented to the clinic with hirsutism and irregular menstruation; upon physical examination, a large abdominal mass was accidentally identified; the patient had Doppler ultrasound (Doppler US) and MRI, which both showed a mass arising from the right upper pole of the kidney, fine needle aspiration (FNA) confirmed the diagnosis of retroperitoneal liposarcoma, patient underwent surgical removal and her symptoms disappeared. Clinical discussion: The retroperitoneum is a cavity behind the abdominal wall containing organs like the pancreas and kidneys. Retroperitoneal tumors (RPTs) are rare neoplasms, primarily of mesenchymal origin. Retroperitoneal liposarcomas (RPLPS) are the most common RPT, often asymptomatic until large, and rarely metastasize but frequently recur. Liposarcomas are classified into five subtypes, with well-differentiated liposarcoma being the most common and characterized by high local recurrence. The presence of specific oncologic mutations affects the prognosis and the response to treatment. Conclusion: In rare cases, retroperitoneal liposarcomas can arise from sites near the kidney and compress the adjoining adrenal gland.

Uncommon Presentation Of A Giant Retroperitoneal Liposarcoma: A Peculiar Case Study

Introduction: Soft tissue sarcomas constitute less than 1% of all neoplasms, with approximately one-third of malignant tumors in the retroperitoneum being sarcomas. Among these, liposarcoma emerges as the most prevalent type. Retroperitoneal liposarcomas with intraperitoneal extension and extension into the inguinal canal are relatively uncommon, presenting a challenge for treatment due to their local aggressiveness and clinical nonspecificity. The clinical difficulty in managing these cases is exacerbated by patients often seeking medical attention late in the disease progression. The slow development and the scarcity of symptoms in the early stages contribute to delayed reporting. Consequently, these tumors are recognized for their capacity to reach enormous sizes before being diagnosed and addressed. Case Report: We present a case involving a 52-year-old man who underwent surgical resection for a massive, well-differentiated retroperitoneal liposarcoma. This tumor exhibited intraperitoneal extension and weighed a substantial 6.8 kilograms. Discussion: Retroperitoneal liposarcomas (RPS) frequently manifest as large, locally advanced lesions. The occurrence of RPS with intraperitoneal extension and extension into the inguinal canal is relatively uncommon. The clinical presentation is often delayed, attributed to the expansive nature of the retroperitoneal space. Evaluating these tumors necessitates a comprehensive, multimodal approach. Given that most RPS are characterized as low-grade, distant metastasis is infrequent, and the primary challenge lies in achieving effective local control and preventing recurrence. The preferred treatment involves radical resection of these tumors, incorporating en bloc resection of involved structures. In certain cases, the strategic use of neoadjuvant and adjuvant therapies, tailored to specific tumor histologies, may enhance local control and overall survival. Conclusion: Effectively managing retroperitoneal liposarcomas necessitates a multidisciplinary approach, ideally conducted at high-volume centers that specialize in the treatment of patients facing these intricate malignancies. Existing data indicate that radical resection stands as the primary opportunity for a cure. In select cases, chemotherapy and radiation therapy may offer a survival benefit, underlining the importance of individualized treatment strategies based on the specific characteristics of the tumor and the patient

Liposarcoma del cordón espermático

Introduction: liposarcoma of the spermatic cord (LSC) is a rare condition and accounts for about 3 to 7% of all paratesticular sarcomas. A case is presented in an 80-year-old patient who consulted for a left inguinoscrotal painless swelling, that had been present for several years. Physical examination revealed a soft left hemiscrotal tumor that appeared not to be adherent to the testicle. Ultrasonography showed a solid, heterogeneous hyperschoic paratesticular mass with central calcifications and peripheral hypervascularity. During surgery, a diffuse lipomatous tumor was found in the spermatic cord on the superior pole of the left testicle, separated from it. Anatomopathological examination revealed a well-differentiated liposarcoma of the spermatic cord. Discussion: this neoplasm features a slow-growing palpable paratesticular mass. This site of occurrence is rare and represents 7 to 10% of all scrotal tumors. Imaging differentiation between LSC and benign lesions is sometimes challenging. Surgical treatment should include radical orchiectomy wide local excision, and spermatic cord and inguinal ring surrounding soft tissue resection. Conclusion: spermatic cord liposarcoma is a rare and unusual mesenchymal tumor and should be considered among the differential diagnoses of scrotal tumors.

A metabolic crosstalk between liposarcoma and muscle sustains tumor growth

Dedifferentiated and Well-differentiated liposarcoma are characterized by a systematic amplification of the Murine Double Minute 2 (MDM2) oncogene. We demonstrate that p53-independent metabolic functions of chromatin-bound MDM2 are exacerbated in liposarcoma and mediate an addiction to serine metabolism to sustain tumor growth. However, the origin of exogenous serine remains unclear. Here, we show that elevated serine levels in mice harboring liposarcoma-patient derived xenograft, released by distant muscle is essential for liposarcoma cell survival. Repressing interleukine-6 expression, or treating liposarcoma cells with Food and Drugs Administration (FDA) approved anti-interleukine-6 monoclonal antibody, decreases de novo serine synthesis in muscle, impairs proliferation, and increases cell death in vitro and in vivo. This work reveals a metabolic crosstalk between muscle and liposarcoma tumor and identifies anti-interleukine-6 as a plausible treatment for liposarcoma patients.

Predictive Value of Quantitative Parameters of 18F-FDG PET/CT in Patients with Liposarcoma.

The purpose of this study was to evaluate the predictive features of baseline F-18-fluorodeoxy-D-glucose positron emission tomography (18F-FDG PET)/computed tomography (CT) parameters in patients with dedifferentiated liposarcomas (DDLPSs) and well-differentiated liposarcomas (WDLPSs) receiving systemic treatment. A total of 24 patients with liposarcoma who underwent longitudinal 18F-FDG PET/CT in systemic therapy were included. All volumetric segmentation of each tumor section and semiquantitative imaging parameters were extracted from the axial field of view from both PET and CT images. Maximum, mean, and minimum standardized uptake values (SUVmax, SUVmean, and SUVmin), Hounsfield units (HUs), and their respective changes from baseline and posttreatment were calculated. The voxel values from unenhanced CT images were correlated with PET-derived parameters. The 18F-FDG uptake decreased by more than 56% on average in responders for both SUVmax and SUVmean in DDLPS. There was a decrease in HUmax in DDLPS among responders. Using AUC > 0.8 as a reasonable predictor, we found that the ratios of SUVmaxD/HUmean, SUVmaxD/HUmedian, and SUVmeanD/HUmedian at baseline were significant indicators of the response to treatment in patients with liposarcoma. The changes in SUVmean and not just SUVmax parameters could be considered as accurate tumor response indicators. For the first time, we introduced baseline SUV/HU ratios as a valuable diagnostic tool in predicting liposarcoma treatment outcomes. This ability was not revealed by classic semiquantitative PET or CT parameters at baseline.

A 24-kilogram retroperitoneal liposarcoma surgical management: A case report

Sarcomas are diverse malignant tumors originating from soft tissues (STS) or bones, with STS being more prevalent. Liposarcoma is the most common type of STS, typically arising in the extremities and retroperitoneum. This case report discusses the management of a rare, giant retroperitoneal liposarcoma (RL) in a 47-year-old man presented with significant abdominal enlargement, post-pharyngeal discharge, and urinary dribbling. Medical history included an inguinal hernia and smoking. Diagnosis through imaging (sonography, CT, MRI) and biopsy confirmed a well-differentiated liposarcoma encasing the left kidney and compressing abdominal organs. The tumor measured 53 × 47 x 20 cm and weighed 24 kg. Surgical management included complete tumor excision, left nephrectomy, iliac artery repair, colectomy, and lymph node dissection. The management of RL is challenging due to its size and proximity to vital organs. Complete surgical resection is crucial for recurrence-free survival. Preoperative radiotherapy can aid in achieving negative margins by defining target volumes and reducing irradiation of adjacent tissues. Chemotherapy is reserved for high-grade tumors with metastatic potential. This report highlights the complexities of managing giant RL, underscoring the importance of thorough surgical planning, multidisciplinary collaboration, and assessing potential adjunct therapies to improve patient prognosis.

Diagnostic Accuracy of Immunohistochemical Expression of p16, MDM2, and CDK4 in Well-Differentiated and De-Differentiated Liposarcoma in MDM2 Fluorescent in situ Hybridisation Confirmed Cases.

To establish the diagnostic utility of immunohistochemistry markers p16 along with MDM2 and CDK-4 in confirming the diagnosis of well-differentiated and de-differentiated liposarcoma while taking Fluorescent in situ Hybridisation (FISH) as a gold standard. A cross-sectional study. Place and Duration of the Study: Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from 30th January 2022 to 30th June 2023. A standard panel of three immunohistochemistry markers p16, MDM2, and CDK4 were applied to 36 cases of atypical lipomatous tumours, well-differentiated liposarcoma (WDLPS), and de-differentiated liposarcoma (DDLPS), on which the gold standard FISH was already performed. The sample size was calculated with the help of a WHO calculator taking prevalence 1-2% in Pakistani population. Qualitative variables such as gender and site of tumour were presented by calculating frequency and percentages and comparison of Immunohistochemistry results with FISH was done by using a 2x2 table. The sensitivity and specificity of this triple marker panel for detecting WDLPS/DDLPS were 43.47% and 15.38%, respectively. The sensitivity and specificity of CDK4 for detecting WDLPS / DDLPS were 82.6% and 15.4%, those of MDM2 were 73.9% and 61.5 %, and those of p16 were 60.9% and 53.8%, respectively. Among all three markers, CDK4 was the most sensitive and MDM2 was the most specific marker for detecting WDLPS-DDLPS. It also showed that a combination of these three markers improves the diagnostic credibility of the immunohistochemistry in diagnosing DDLPS and WDLPS but FISH is the most reliable and confirmatory method. De-differentiated liposarcoma, Well-differentiated liposarcoma, P16, CDK4, MDM2.

Targeting Asparagine Metabolism in Well-Differentiated/Dedifferentiated Liposarcoma.

mTORC1 activity is dependent on the presence of micronutrients, including Asparagine (Asn), to promote anabolic cell signaling in many cancers. We hypothesized that targeting Asn metabolism would inhibit tumor growth by reducing mTORC1 activity in well-differentiated (WD)/dedifferentiated (DD) liposarcoma (LPS). Human tumor metabolomic analysis was utilized to compare abundance of Asn in WD vs. DD LPS. Gene set enrichment analysis (GSEA) compared relative expression among metabolic pathways upregulated in DD vs. WD LPS. Proliferation assays were performed for LPS cell lines and organoid models by using the combination treatment of electron transport chain (ETC) inhibitors with Asn-free media. 13C-Glucose-labeling metabolomics evaluated the effects of combination treatment on nucleotide synthesis. Murine xenograft models were used to assess the effects of ETC inhibition combined with PEGylated L-Asparaginase (PEG-Asnase) on tumor growth and mTORC1 signaling. Asn was enriched in DD LPS compared to WD LPS. GSEA indicated that mTORC1 signaling was upregulated in DD LPS. Within available LPS cell lines and organoid models, the combination of ETC inhibition with Asn-free media resulted in reduced cell proliferation. Combination treatment inhibited nucleotide synthesis and promoted cell cycle arrest. In vivo, the combination of ETC inhibition with PEG-Asnase restricted tumor growth. Asn enrichment and mTORC1 upregulation are important factors contributing to WD/DD LPS tumor progression. Effective targeting strategies require limiting access to extracellular Asn and inhibition of de novo synthesis mechanisms. The combination of PEG-Asnase with ETC inhibition is an effective therapy to restrict tumor growth in WD/DD LPS.

Giant retroperitoneal liposarcoma with multiple organ involvement: a case report and literature review

BackgroundRetroperitoneal liposarcoma (RPLPS) is a relatively rare disease. Liposarcomas vary in size, but sizeable RPLPS larger than 30 cm in diameter are very rare, and their diagnosis and treatment present significant challenges.Case presentationWe report a 58-year-old male patient who was admitted to the hospital with an increased abdominal circumference and was later diagnosed with a giant RPLPS. The liposarcoma was found to adhere to the right kidney and the entire ureter, invading the ascending colon. The patient underwent complete combined surgical resection. The tumor was removed intact, measured 55.0 cm × 30.0 cm × 18.0 cm, and weighed 19.8 kg. Histopathologic analysis revealed well-differentiated liposarcoma (WDLPS). The patient was successfully discharged from the hospital and followed up for 6 months with no signs of recurrence.ConclusionRPLPS is a rare tumor with atypical clinical presentation. Surgery remains the most effective method of treatment for retroperitoneal sarcomas, with complete removal if there is local invasion. Preoperative examination, including three-dimensional (3D) reconstruction, is essential for surgical success. The role of adjuvant radiotherapy or chemotherapy remains controversial. However, clinicians should not rule them out as viable options.

Combined use of composite mesh and acellular dermal matrix graft for abdominal wall repair following tumour resection

BackgroundSurgeries for sarcomas in the abdominal wall require wide resections, often radical en bloc resections, which generate major defects involving a very complex repair. The combined use of porcine dermal xenografts, together with composite meshes, may assist in the repair of these defects with minimal complications.MethodWe present a series of 19 patients (10 males and 9 females), with a mean age of 53.2 years (range: 11–86 years) treated in the Sarcoma Unit of the Virgen de la Arrixaca University Hospital from January 2015 to December 2021. Histopathologically, there were four chondrosarcomas (21%), three Ewing sarcomas (15.7%), two desmoid tumours (10.5%), two undifferentiated pleomorphic sarcomas (10.5%), two well-differentiated liposarcomas (10.5%), two leiomyosarcomas (10.5%), one synovial sarcoma, one dermatofibrosarcoma protuberans, one fibromyxoid sarcoma (or Evans tumour), and one metastasis from an adenocarcinoma of unknown origin. All the patients were resected following surgical oncology principles and reconstructed by means of the combined use of a composite mesh acting as a neoperitoneum and a porcine dermal xenograft acting as an abdominal neofascia.ResultsThe mean size of the defects generated after surgery for tumour excision was 262.8 cm2 (range: 150–600 cm2). After a mean follow-up of 38 months, six patients (31.5%) developed complications—two cases of wound dehiscence, one case of surgical wound infection, one case of graft partial necrosis, one case of anastomotic leak and one death due to multiorgan failure secondary to massive bronchoaspiration.ConclusionSurgeries for sarcomas of the abdominal wall require wide oncological resections, which generate major abdominal wall defects. The repair of these defects by means of the combined use of synthetic and biological meshes is a technique associated with minimal complications and excellent medium-term results.

A Case of Dedifferentiated Liposarcoma That Contributes to Accompanying Vessels of Various Size.

Dedifferentiated liposarcoma (DDLPS) is a non-lipogenic sarcoma, generally arising from well-differentiated liposarcoma (WDLPS), although it can develop de novo. DDLPS tumors rarely trans-differentiate into non-adipose mesenchymal tissues; however, the latter lack notable variety and mostly show striated muscle or osteogenic/chondrogenic differentiation. Here, we report a case of DDLPS that contained numerous atypical vessels. A man in his sixties presented with a large tumor in his right thigh, and the tumor was surgically resected. Microscopically, most of the tumor was WDLPS, but a minor portion showed DDLPS, consisting of high-grade spindle cells. Remarkably, the DDLPS contained vessels of various sizes with atypical cytoarchitecture, including vessels with seemingly muscular layers. Immunohistochemically, the atypical cells within the vascular wall expressed aSMA, consistent with smooth muscle cells or pericytes, whereas surrounding high-grade spindle cells only focally expressed it, and these aSMA-positive cells within the vessels exhibited MDM2 amplification by immuno-fluorescence in situ hybridization. Our results demonstrate that DDLPS can trans-differentiate into smooth muscle cells of various-sized accompanying vessels, which may support their survival and proliferation.

Optimizing surgical strategies for retroperitoneal liposarcoma: a comprehensive evaluation of standardized aggressive surgical policies

BackgroundRetroperitoneal liposarcoma (RLPS) constitutes the majority of retroperitoneal sarcomas. While surgical resection remains the sole curative approach, determining the optimal surgical strategy for RLPS remains elusive. This study addresses the ongoing debate surrounding the optimal surgical strategy for RLPS.MethodsWe recruited 77 patients with RLPS who underwent aggressive surgical policies. Patients were categorized into three surgical subtypes: suprapancreatic RLPS, pancreatic RLPS, and subpancreatic RLPS. Our standardized surgical strategy involved resecting macroscopically uninvolved adjacent organs according to surgical subtypes. We collected clinical, pathological and prognostic data for analyses.ResultsThe median follow-up was 45.5 months. Overall survival (OS) and recurrence-free survival (RFS) were significantly correlated with multifocal RLPS, pathological subtype, recurrent RLPS and histological grade (P for OS = 0.011, 0.004, 0.010, and < 0.001, P for RFS = 0.004, 0.001, < 0.001, and < 0.001, respectively). The 5-Year Estimate OS of well-differentiated liposarcoma (WDLPS), G1 RLPS, de novo RLPS and unifocal RLPS were 100%, 89.4%, 75.3% and 69.1%, respectively. The distant metastasis rate was 1.4%. The morbidity rates (≥ grade III) for suprapancreatic, pancreatic, and subpancreatic RLPS were 26.7%, 15.6%, and 13.3%, respectively. The perioperative mortality rate is 2.6%.ConclusionsStandardized aggressive surgical policies demonstrated prognostic benefits for RLPS, particularly for G1 RLPS, WDLPS, unifocal RLPS, and de novo RLPS. This approach effectively balanced considerations of adequate exposure, surgical safety, and thorough removal of all fat tissue. G1 RLPS, WDLPS, unifocal RLPS, and de novo RLPS could be potential indications for aggressive surgical policies.

Preoperative Contrast-Enhanced CT-Based Deep Learning Radiomics Model for Distinguishing Retroperitoneal Lipomas and Well‑Differentiated Liposarcomas

ObjectivesTo assess the efficacy of a preoperative contrast-enhanced CT (CECT) –based deep learning radiomics nomogram (DLRN) for predicting murine double minute 2 (MDM2) gene amplification as a means of distinguishing between retroperitoneal well-differentiated liposarcomas (WDLPS) and lipomas. MethodsThis retrospective multi-centre study included 167 patients (training/external test cohort, 104/63) with MDM2-positive WDLPS or MDM2-negative lipomas. Clinical data and CECT features were independently measured and analyzed by two radiologists. A clinico-radiological model, radiomics signature (RS), deep learning and radiomics signature (DLRS), and a DLRN incorporating radiomics and deep learning features were developed to differentiate between WDLPS and lipoma. The model utility was evaluated based on the area under the receiver operating characteristic curve (AUC), accuracy, calibration curve, and decision curve analysis (DCA). ResultsThe DLRN showed good performance for distinguishing retroperitoneal lipomas and WDLPS in the training (AUC, 0.981; accuracy, 0.933) and external validation group (AUC, 0.861; accuracy, 0.810). The DeLong test revealed the DLRN was noticeably better than clinico-radiological and RS models (training: 0.981 vs. 0.890 vs. 0.751; validation: 0.861 vs. 0.724 vs. 0.700; both P < 0.05); however, no discernible difference in performance was seen between the DLRN and DLRS (training: 0.981 vs. 0.969; validation: 0.861 vs. 0.837; both P > 0.05). The calibration curve analysis and DCA demonstrated that the nomogram exhibited good calibration and offered substantial clinical advantages. ConclusionsThe DLRN exhibited strong predictive capability in predicting WDLPS and retroperitoneal lipomas preoperatively, making it a promising imaging biomarker that can facilitate personalized management and precision medicine.

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.