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Liposarcoma is the commonest soft tissue neoplasm, usually located in the deep soft tissue of the limbs. The central nervous system (CNS) as the primary site is exceedingly rare. We report a 35-year-old male patient who presented with seizure and weakness of the left half of the body for three months. The magnetic resonance imaging of the brain revealed a large solid partially necrotic lesion in the right posterior frontal lobe with perilesional edema. The tumour was firm, intra-axial, not adherent to the dura, and was completely excised. Based on the morphology, immunohistochemistry, and imaging findings, the diagnosis of primary intracerebral pleomorphic liposarcoma was rendered. Post-operatively, the patient had an uneventful follow-up. Pleomorphic liposarcoma is a rare CNS tumor with aggressive behavior, high potential for local recurrence, and distant metastasis. However, the acquaintance with intracranial liposarcoma is limited because of its rarity, and thus, no standard treatment protocol is of consensus. [ABSTRACT FROM AUTHOR]

Objective: To update the current Sarculator retroperitoneal sarcoma (RPS) prognostic nomograms considering the improvement in patient prognosis and the case volume effect. Background: Survival of patients with primary RPS has been increasing over time, and the volume–outcome relationship has been well recognized. Nevertheless, the specific impact on prognostic nomograms is unknown. Methods: All consecutive adult patients with primary localized RPS treated at 8 European and North American sarcoma reference centers between 2010 and 2017 were included. Patients were divided into 2 groups: high-volume centers (HVC, ≥13 cases/year) and low-volume centers (LVC, <13 cases/year). Primary end points were overall survival (OS) and disease-free survival (DFS). Multivariable analyses for OS and DFS were performed. The nomograms were updated by recalibration. Nomograms performance was assessed in terms of discrimination (Harrell C index) and calibration (calibration plot). Results: The HVC and LVC groups comprised 857 and 244 patients, respectively. The median annual primary RPS case volume (interquartile range) was 24.0 in HVC (15.0–41.3) and 9.0 in LVC (1.8–10.3). Five-year OS was 71.4% (95% CI: 68.3%–74.7%) in the HVC cohort and 63.3% (56.8%–70.5%) in the LVC cohort (P= 0.012). Case volume was associated with both OS (LVC vs. HVC hazard ratio 1.40, 95% CI: 1.08–1.82, P=0.011) and DFS (hazard ratio 1.93, 95% CI: 1.57–2.37, P< 0.001) at multivariable analyses. When applied to the study cohorts, the Sarculator nomograms showed good discrimination (Harrell C index between 0.68 and 0.73). The recalibrated nomograms showed good calibration in the HVC group, whereas the original nomograms showed good calibration in the LVC group. Conclusions: New nomograms for patients with primary RPS treated with surgery at high-volume versus low-volume sarcoma reference centers are available in the Sarculator app. [ABSTRACT FROM AUTHOR]

Curative management of retroperitoneal sarcoma relies on surgery, and complete monoblock resection is one of the main prognostic factors. The goal of this study was to search predictive factors for incomplete resection. All patients undergoing surgery for retroperitoneal sarcoma in two University hospitals between 2010 and 202 were included. The main endpoint was incomplete resection (R1 ad R2) after surgery. Secondary analysis was performed where marginal R0 resection was considered as complete. Univariate and multivariable analysis of demographics, radiological, surgical and pathologic criteria were performed. Overall survival, local and distant recurrence were evaluated. Fifty-eight patients were included in the study. Fifty patients had incomplete resection, of which seven had marginal R0 resection. In multivariable analysis, none of the factors analyzed were associated with incomplete resection. In secondary analysis, undifferentiated liposarcoma histology (OR 12.3, 95% CI [1.416–107.303], P = 0.023) was statistically significantly associated with incomplete resection. Low grade (grade I) histology was predictive of complete resection (OR 0.24, 95% CI [0.060–0.959], P = 0.043). Median follow-up duration was 27 months. Local and distant recurrence rates at three years were 37% and 22.4%, respectively. In this study, we highlighted several predictive factors for incomplete resection. These factors enable us to define target populations that could most benefit from complementary therapy along with surgery. [ABSTRACT FROM AUTHOR]

Myxoid liposarcoma is an extremely rare malignant breast tumor. We report the case of a 44-year-old woman who had myxoid liposarcoma of the breast with a history of phyllodes tumor and describe the imaging findings on US, mammography, and MRI. Before surgery, the mass was considered to be a recurrent phyllodes tumor. However, using US, we retrospectively identified some differences between myxoid liposarcomas and phyllodes tumors. [ABSTRACT FROM AUTHOR]

To evaluate the outcomes of adult patients with spermatic cord sarcoma (SCS). All consecutive patients with SCS managed by the French Sarcoma Group from 1980 to 2017 were analysed retrospectively. Multivariate analysis (MVA) was used to identify independent correlates of overall survival (OS), metastasis-free survival (MFS), and local relapse-free survival (LRFS). A total of 224 patients were recorded. The median age was 65.1 years. Forty-one (20.1%) SCSs were discovered unexpectedly during inguinal hernia surgery. The most common subtypes were liposarcoma (LPS) (73%) and leiomyosarcoma (LMS) (12.5%). The initial treatment was surgery for 218 (97.3%) patients. Forty-two patients (18.8%) received radiotherapy, 17 patients (7.6%) received chemotherapy. The median follow-up was 5.1 years. The median OS was 13.9 years. In MVA, OS decreased significantly with histology (HR, well-differentiated LPS versus others = 0.096; p = 0.0224), high grade (HR, 3 versus 1–2 = 2.7; p = 0.0111), previous cancer and metastasis at diagnosis (HR = 6.8; p = 0.0006). The five-year MFS was 85.9% [95% CI: 79.3–90.6]. In MVA, significant factors associated with MFS were LMS subtype (HR = 4.517; p < 10-4) and grade 3 (HR = 3.664; p < 10-3). The five-year LRFS survival rate was 67.9% [95% CI: 59.6–74.9]. In MVA, significant factors associated with local relapse were margins and wide reresection (WRR) after incomplete resection. OS was not significantly different between patients with initial R0/R1 resection and R2 patients who underwent WRR. Unplanned surgery affected 20.1% of SCSs. A nonreducible painless inguinal lump should suggest a sarcoma. WRR with R0 resection achieved similar OS to patients with correct surgery upfront. [ABSTRACT FROM AUTHOR]

A 9-year-old female meerkat (Suricata suricatta) succumbed to progressive abdominal distension, anorexia, and depression. Necropsy revealed an extensively distended abdomen with ascites and markedly enlarged liver. The liver had multiple yellowish masses and displaced the thoracic cavity and abdominal organs. There was no evidence of metastatic lesions based on the gross and microscopic findings. Histologically, the liver mass was composed of locally invasive welldifferentiated neoplastic adipocytes with Oil Red O-positive lipid vacuoles. Immunohistochemistry revealed positive immunoreactivity to vimentin, S-100 and negative to pancytokeratin, desmin, smooth muscle actin (SMA), ionized calcium-binding adapter molecule 1 (IBA-1). Thus, the primary well differentiated hepatic liposarcoma was diagnosed based on gross, histological and immunohistochemistry results. [ABSTRACT FROM AUTHOR]

Primary non-metastatic retroperitoneal soft tissue sarcoma patients can be cured by radical surgery. However there remains a risk for patients to develop a local recurrence. To minimize this risk, patients with low grade liposarcomas might benefit from preoperative radiotherapy. This review summarizes all issues that should be considered for the irradiation of patients with retroperitoneal soft tissue sarcoma. • Radiotherapy (RT) is not standard of care for an unselected group of RPS patients • Within the most prevalent RPS-subgroup of liposarcomas, an improved recurrence-free survival after preoperative RT may be observed • Timing, patient preparation, delineation and doses are summarized for RT in RPS • Referral of all RPS patients to specialized RPS centers is highly recommended [ABSTRACT FROM AUTHOR]

Pelvic soft tissue sarcomas (PSTS) are a rare, heterogeneous group of tumors. They have been usually analyzed with retroperitoneal sarcomas (RPS), but actually have key differences. Due to their unique anatomic location, symptomatic presentation of PSTS may be more common than RPS. Adequate imaging approach is paramount for guiding differential diagnosis, while preoperative biopsy is mandatory, especially when preoperative treatment may be considered as initial approach. The most frequent histologic subtype is leiomyosarcoma, which is different as expected in the retroperitoneum where liposarcoma is the commonest histology. Also solitary fibrous tumor is commonly diagnosed in the pelvis. Surgical approach for PSTS differs from that for RPS mainly due to anatomic relations. Similarly, in the lack of definite evidence from specific trials about neoadjuvant and adjuvant treatments, the anatomic constraints to obtain wide margins in the pelvis as well as the expected functional outcome in case of organ resections should be factored into decision for individualized treatment offer. Vascular and genitourinary involvement are frequent, as well as herniation through pelvic foramina. For these reasons a multidisciplinary surgical team should always be considered. Early referral of these patients to high-volume centers is critical and may impact on survival, given that optimal initial resection is a major predictor of curative treatment. International consensus on PSTS treatment is advocated, similarly to the recent efforts realized for RPS. - Adequate imaging and biopsy are crucial for diagnosis and planning surgical approach - Histologic subtypes are different in pelvic sarcomas compared to retroperitoneal - Multimodal treatment is frequently adopted at referral centers - Pelvic anatomy impacts functional outcome and decision for preoperative therapy - Benefit from referral to high volume centers and histology driven tailored approach [ABSTRACT FROM AUTHOR]

Until recently, the recommendation for primary retroperitoneal sarcomas (RPS) was to perform a complete en-bloc gross excision, (neo) adjuvant treatments being options which were not validated by randomized studies, with a large discrepancy of use between centers. The heterogeneity of RPS, with their different biological behaviour, renders a homogenous therapeutic and surgical approach probably inappropriate. Recent studies, both surgical and dedicated to adjuvant treatments, allow refining these recommendations. This review summarizes recent advances and directions. [ABSTRACT FROM AUTHOR]

Almost half of retroperitoneal (RP) sarcomas are liposarcomas (LPS). The large majority of RP LPS are either well-differentiated LPS (WDLPS) or dedifferentiated LPS (DDLPS), these latter further classified according to grading in G2 and G3 DDLPS. Surgery is the only potentially curative treatment to achieve local control and possibly cure in primary localized disease. Over the last decade, a better delineation of the different histology-specific patterns of failure and the development of nomograms predictors of outcome has led to a better management of these rare tumors, with a special focus on non-surgical treatments. Available evidences – although far from exhaustive – show that radiation therapy might have a role, if any, as neoadjuvant treatment in locally aggressive histologies (i.e. WDLPS and G2 DDLPS), while it does not seem beneficial for histologies with a higher metastatic risk (i.e. G3 DDLPS and leiomyosarcoma). Neoadjuvant chemotherapy, instead, can be considered to reduce the risk of distant metastasis while waiting for the results of an ongoing RCT (STRASS-2) evaluating its effect in these tumors. However, given the rarity of these diseases and the subsequent lack of strong evidences to guide treatment, outcome improvement in these patients remains a challenge. Patients' referral to a sarcoma center where a dedicated specialized multidisciplinary team tailor optimal treatment on a case-by-case basis is crucial to ensure these patients the best outcome. Refining available nomograms – e.g including molecular variables – and identifying predictors of response/toxicity to chemotherapy and immunotherapy might be significantly helpful in tailoring treatments to the patient's characteristics. Also, new systemic agents are eagerly awaited for improving the management further. [ABSTRACT FROM AUTHOR]

Retroperitoneal sarcomas (RPS) refer to a heterogeneous group of malignancies of mesenchymal origin developing from retroperitoneal tissues and vessels. The most frequent RPS are well differentiated/dedifferentiated liposarcomas and leiomyosarcomas, but other rare histological subtypes can be observed. Over the last decade, significant advances have been made in the pathological and molecular characterization of sarcomas. These advances have led to major changes in their diagnostic management as well as in the development of new therapeutic strategies based on tumor biology and microenvironment. This review describes the current knowledge and recent findings in the pathology and molecular biology of the most frequent RPS subtypes. [ABSTRACT FROM AUTHOR]

Retroperitoneal soft tissue sarcomas mainly consist histologically of liposarcomas and leiomyosarcomas. For the liposarcoma subgroup, the local relapse rate seems to determine patients' overall prognosis. In contrast, leiomyosarcoma patients are challenged by the development of metastatic disease; therefore, effective systemic therapies are the cornerstone to improve patients' outcome. No doubt, the limited number of active regimens currently available makes the treatment of patients with locally advanced and/or metastatic disease challenging and results in the overall poor prognosis of this population. In this European Journal of Surgical Oncology Educational Special Issue from the Transatlantic Australasian RetroPeritoneal Sarcoma Working Group (TARPSWG), we aim to summarize state-of-the-art systemic treatments for patients with retroperitoneal sarcomas with a focus on the locally advanced and metastatic disease setting including conventional standard chemotherapies as well as new innovative treatment approaches in order to identify current unmet medical needs guiding the sarcoma community to initiate appropriate translational research projects and design innovative clinical trials. [ABSTRACT FROM AUTHOR]

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Compared with other soft tissue sarcomas, myxoid liposarcoma (MLS) occurs in younger patients, has a propensity for intermuscular locations and is highly radiosensitive. With pre-operative radiotherapy, intermuscular MLS demonstrates substantial volume reduction and can be easily separated from surrounding tissues during resection. However, it is unclear whether marginal excision of MLS is oncologically safe. This study aimed to assess the association between margins and survival in irradiated, intermuscular MLS. The study identified 198 patients from seven sarcoma centres with a first presentation of localized, extremity, intermuscular MLS that received pre-operative radiotherapy and was diagnosed between 1990 and 2017. Patient and treatment characteristics, radiological and histological responses to neoadjuvant treatment and clinical surveillance were recorded. Margins were microscopically positive in 11% (n = 22), <1.0 mm in 15% (n = 29) and ≥1.0 mm in 72% (n = 143). There was no association between margin status and local recurrence-free, metastasis-free or overall survival. This finding held true even in patients at higher risk of worse overall survival based on multivariable analysis (% round cell≥5%, percentage ellipsoid tumour volume change ≤ -60.1%). Irradiated, extremity, intermuscular myxoid liposarcoma can safely undergo marginal resection without compromising oncologic control. Following pre-operative radiotherapy, extremity intermuscular myxoid liposarcoma can be marginally resected without compromising local recurrence-free, metastasis-free or overall survival. [ABSTRACT FROM AUTHOR]

Dedifferentiated liposarcoma occurs predominantly in the retroperitoneum. Given the paucity of cases, information on the clinical characteristics of this entity in the extremities and trunk wall is quite limited. In particular, the significance of preoperative evaluation and principles of intraoperative management of the different components, i.e., well-differentiated and dedifferentiated areas, are still to be defined. Clinical characteristics, treatment outcomes, and risk factors for poor oncological outcomes in cases of dedifferentiated liposarcoma in the extremity or trunk wall were analyzed by a retrospective, multicentric study. A total of 132 patients were included. The mean duration from the initial presentation to dedifferentiation was 101 months in dedifferentiation-type cases. The 5-year local recurrence-free survival, metastasis-free survival, and disease-specific survival rates were 71.6%, 75.7%, and 84.7%, respectively. Among 32 patients with metastasis, 15 presented with extrapulmonary metastasis. A percentage of dedifferentiated area over 87.5%, marginal/intralesional margin, and R1/2 resection in the dedifferentiated area were independent risk factors for local recurrence. Dedifferentiated areas over 36 cm2, French Federation of Cancer Centers Sarcoma Group grade III, and intralesional or marginal resection were independent risk factors for metastasis. A dedifferentiated area over 77 cm2 and lung metastasis were independent risk factors for disease-specific mortality. The typical clinical characteristics of dedifferentiated liposarcoma in the extremity and trunk wall were reconfirmed in the largest cohort ever. The evaluation of the dedifferentiated area in terms of grade, extension, and pathological margin, together with securing adequate surgical margins, was critical in the management of this entity. ● The mean time to dedifferentiation was 101 months in dedifferentiation type. ● The 5-year local recurrence and metastasis-free survival were 71.6% and 75.7%. ● The 5-year disease-specific survival rate was 84.7%. ● Among 32 patients with metastasis, 15 presented with extrapulmonary metastasis. ● Grade, extension, and margin in the dedifferentiated area are critical to outcomes. [ABSTRACT FROM AUTHOR]

When obstructive lesions from the uterus or ovaries are suspected, patients with hydronephrosis are usually referred to a gynecologist. Here, a case of suspected endometriosis‑related hydroureteronephrosis is reported. A 43‑year‑old woman with hydronephrosis was found to have a left distal periureteral tumor on the computerized tomography scan. Before the operation, the hydroureteronephrosis was suspected caused by the obstruction of ureter, related with ureteral endometriosis; however, the postoperative pathology revealed the diagnosis of retroperitoneal well‑differentiated liposarcoma. When female patients have hydronephrosis, gynecologic causes should be considered. Both benign and malignant causes are needed to include when making differential diagnosis. Therefore, robot‑assisted surgery is a feasible option because of its lower morbidity rate and more precise dissection of soft tissue than laparotomy in both benign and malignant retroperitoneal tumors. [ABSTRACT FROM AUTHOR]

Pelvic sarcomas are a rare and heterogenous group of tumors divided into two groups: soft tissue sarcomas and bone sarcomas. Soft tissue sarcomas of the pelvis include most commonly liposarcoma, leiomyosarcoma, gastrointestinal stromal tumors, malignant peripheral nerve sheath tumors, and solitary fibrous tumors. Bone sarcomas of the pelvis most commonly include osteosarcoma and chondrosarcoma. Multidisciplinary treatment at a center experienced in the treatment of sarcoma is essential. Management is dictated by histologic type and grade. Surgical resection with wide margins is the cornerstone of treatment for pelvic sarcomas, although this is often challenging due to anatomic constraints of the pelvis. Multimodal treatment is critical due to the high risk of local recurrence in the pelvis. [ABSTRACT FROM AUTHOR]

Clinical outcome data in the United Kingdom, Europe, and the United States have yet to facilitate appropriately specific surveillance for liposarcoma histological subtypes, despite being one of the most common soft tissue sarcomas. Therefore, this study aims to demonstrate histologic-specific differences in liposarcoma recurrence, disease progression, and survival and discuss the implications. This cohort study involves patients from a regional sarcoma service in the UK who have had a primary surgical excision of liposarcoma between October 2002 and September 2019. The median follow-up is five years. Confirmed histopathological diagnoses of liposarcoma (n = 193) are organised according to the World Health Organisation recognised subtypes: atypical lipomatous tumours (ALT), myxoid, pleomorphic, and dedifferentiated liposarcomas. In addition, retroperitoneal variants (n = 34) are included to illustrate the broader spectrum of phenotypes. The primary outcomes were local recurrence, distant disease progression, and disease-specific death, and compared using Kaplan–Meier analyses and tumour variables using Cox proportional hazard analyses. All three primary outcomes significantly differed (P < 0.0001, n = 193). There were no metastases or disease-specific death in patients with ALT (n = 92) and no metastases of their retroperitoneal counterparts (n = 17). Amongst the metastasising cases of rarer subtypes, there were pulmonary spread of pleomorphic (8/9, n = 20), dedifferentiated (4/5, n = 18), and myxoid (2/3, n = 29) liposarcomas. An absence of metastases of ALT should be considered alongside global evidence. Surveillance protocols could better differentiate between these subtypes and, in doing so, save patients a considerable amount of irradiation, time, fear, and anxiety. [ABSTRACT FROM AUTHOR]

The pleomorphic variant is the least common and consequently, the least known subtype of liposarcomas. It represents <5 % of all liposarcomas and develops during late adulthood. We report the case of a 77-year-old male who presented with pain in the right iliac fossa and right inguinal region. A CT scan revealed a stony lesion at the level of the cecum. A right hemicolectomy was performed, and the pathology report was positive for pleomorphic liposarcoma. Consequently, he was referred for adjuvant radiotherapy. Molecular analysis has validated the distinction of liposarcoma subtypes, although histological subtype remains the reliable prognostic parameter in daily practice, recent evidence suggests that genetic profiles may eventually influence risk stratification of individual patients. The pleomorphic subtype of liposarcomas is infrequent, and they are very rare in the cecum, so it is currently recommended that patients be evaluated by a multidisciplinary team to make a therapeutic decision as it is a subtype of very aggressive behavior, before initiating any type of oncologic treatment. • A very rare case reported in the world literature • Research on the subject based on current books and publications • Adequate treatment options for this pathology • Adequate differential diagnoses • Description of the imminuhistochemistry in the clinical case [ABSTRACT FROM AUTHOR]

This paper outlines the oncological outcomes of patients with large volume liposarcomas of the posterior thigh who underwent nerve-preserving surgery utilising epineural dissection. Thirty-seven consecutive patients (group I) with a mean age of 66.2 (31–96) were surgically treated with a planned marginal resection and epineurectomy for liposarcoma with known sciatic nerve involvement between March 1997 and January 2015. The mean follow-up was 79 months (15–192). All patients underwent multidisciplinary team (MDT) pre-operative assessment and staging, with follow-up in Sarcoma Clinic. Pre-operative function was assessed by applying the Toronto extremity salvage score (TESS). Oncological and functional outcomes were recorded. In grades 1, 2, and 3, 24, 6, and 7 liposarcomas, respectively, were included with mean volume 1859 cm3. Sciatic nerve involvement extended for 13–30 cm; in one case, the nerve was abutting the tumour throughout its length. Soft tissue reconstructive surgery was required in three cases. The remainder underwent direct primary closure. Seventeen patients underwent post-operative adjuvant radiotherapy 46–60 Gy and three received chemotherapy. There was local recurrence of disease in three patients. One patient had post-radiation wound breakdown treated non-operatively. Three patients died of an unrelated cause. When compared to a cohort of 37 patients without sciatic nerve involvement (group II), there were no significant differences in local and systemic recurrence rate or post-operative survival. In conclusion, sciatic nerve-preserving surgery is both possible and safe when using a planned epineural dissection in large volume tumours encasing the sciatic nerve. [ABSTRACT FROM AUTHOR]

Lipomas are common soft-tissue neoplasms, usually present on the trunk and proximal portions of the extremities and less frequently in the mouth. We report the case of a 51-year-old patient affected by an intra-extraoral swelling for eight months. Aspiration, surgical excision and histopathological examination confirmed that it was a simple oral lipoma, although clinically and surgically, it mimicked an infiltrating lipoma. Conservative surgical treatment, preferably using an intraoral approach, results in less morbidity and less sequelae for patients. [ABSTRACT FROM AUTHOR]

Fat-containing tumors are very commonly found in daily practice with benign lipoma accounting for the majority of superficial tumors. Overlap in imaging findings between benign and intermediate or malignant fat-containing tumor is common. Guidelines recommend a core needle biopsy (CNB) for all deep tumors, and superficial tumors over 3 cm. However, specific strategy for diagnosis and referral to a sarcoma center should be applied on adipocytic tumors. The aim of this consensus statement is to provide a specific algorithm for adipocytic tumors, to discriminate patients who do require a CNB for preoperative diagnosis from those who can simply undergo active surveillance or a simple excision. [ABSTRACT FROM AUTHOR]

Tertiary centers recruit a large proportion of locally advanced or recurrent soft tissue sarcomas (STSs) that may have been preoperatively irradiated. The objective of this study was to evaluate the results of oncoplastic surgery (OPS) for patients affected by extremities or parietal trunk STS. This retrospective study includes patients who underwent a flap reconstruction after sarcoma resection between January 2018 and December 2020 at Institut Curie. The primary endpoint was the evaluation of the impact of OPS on the quality of surgical margins. The secondary endpoint was to quantify the morbidity of OPS and identify predictive factors for wound complications. Of 211 patients, 89 (42.2%) had a flap reconstruction. Surgery was realized on an irradiated field in 56 (62.9%) patients. Without OPS, all patients were candidates either for amputation (n = 9,10.1%) due to vessels/nerve infiltration, or R1/R2 resection (n = 80,89.9%). Seventy-two (80.0%) pedicle flaps and 18 (20.0%) free flaps were used. No R2 resections were performed. R0 and R1 margins were achieved in 82 (92.1%) and 7 (7.9%), respectively. The median closest margin was 3 mm (IQR 1–6 mm). Among R1 patients, 5 had positive margins along a preserved critical structure, 2 patients had well-differentiated liposarcomas. The surgical morbidity rate was 33.3% (30/90 flaps). The reoperation rate was 15.7% (14/89 patients). In a referral sarcoma center, the collaboration between the surgical oncologist and the plastic surgery team should be considered upfront in the surgical plan, allowing the most adequate wide oncological resection with acceptable postoperative morbidity. [ABSTRACT FROM AUTHOR]

The surgical management of retroperitoneal sarcomas frequently involves complex multivisceral resections, however retroperitoneal liposarcoma (LPS) rarely invade major abdominal vessels. The aim of the study was to assess association of major vascular resections with outcome of primary LPS. All consecutive patients who underwent resection at our institutions for primary LPS between 2002 and 2019 were included. A propensity matched analysis was performed, adjusting the groups for the variables of Sarculator, to assess the effect of vascular resection on oncological outcomes. Overall 425 patients were identified. Twenty-four (5%) patients had vascular resection. At final pathology 18 patients had vascular infiltration, 2 vascular encasement and 4 involvement without infiltration. Vascular resection was associated with longer operative time (480′ vs. 330'; p < 0.001) and greater need for transfusions (4 vs. 0 units; p < 0.001), and was burdened by a higher rate of major complications (54% vs. 25%; p = 0.002). After propensity matched analysis, patients undergoing vascular resection had a lower 5-year OS (60% vs. 81%; p = 0.05), and a higher incidence of local and distant recurrence at 5 years (local: 45% vs. 24%, p = 0.05; distant: 20% vs. 0%, p = 0.04). Vascular resection is feasible and safe even in the context of multivisceral resection for primary retroperitoneal liposarcomas, although associated to a higher complication rate. However, the independent association between vascular involvement and a higher risk of local recurrence, distant metastases and death may imply a more aggressive biology, which should be factored in the initial management of this complex disease. [ABSTRACT FROM AUTHOR]

Histotype specific neoadjuvant therapy response data is scarce in soft tissue sarcomas. This study aimed to assess the impact of a moderate radiotherapy (RT) dose on resectability and to correlate MRI parameters to pathological treatment response in Myxoid Liposarcoma (MLS). This prospective, multicenter, single-arm, phase 2 trial assessed the radiological effects of 36 Gy of preoperative radiotherapy in primary non-metastatic MLS (n=34). Distance of the tumor to the neurovascular bundle, tumor dimensions, fat fraction, enhancing fraction were determined on MRI scans at baseline, after 8 and 16 fractions, and preoperatively. Pathological response was established by central pathology review. Preoperative radiotherapy resulted in a median increase of 2 mm (IQR 0 to 6) of the distance of the tumor to the neurovascular bundle. As compared to baseline, the median change of the tumor volume, craniocaudal diameter and axial diameter at preoperative MRI were −60% (IQR -74 to -41), −19% (IQR -23 to -7) and −20% (IQR -29 to -12), respectively. The median fat fraction of 0.1 (IQR 0.0–0.1) and enhancing fraction of 0.8 (IQR 0.6 to 0.9) at baseline, changed to 0.2 (IQR 0.1 to 0.5) and to 0.5(IQR 0.4 to 0.9) preoperatively, respectively. Radiological signs of response in terms of volume, enhancing fraction and fat fraction were correlated with specific pathological signs of response like hyalinization, necrosis and fatty maturation. A moderate dose of preoperative radiotherapy may improve resectability in MLS and could facilitate achievement of clear margins and function preservation. MRI features which were predictive for expressions of pathological response, can play a role in further personalization of neoadjuvant treatment strategies in order to improve outcome in MLS. • Myxoid Liposarcomas (MLS) are exceptionally radiosensitive • A moderate dose of preoperative RT may improve resectability in MLS • The tumor to neurovascular bundle distance increases with 2 mm after 36Gy of RT • Volume, enhancing fraction and fat fraction on MRI may predict pathological response [ABSTRACT FROM AUTHOR]

Primary liposarcoma at vallecula is an extremely rare tumor in hypopharyngeal region. Vallecular liposarcoma shares both clinical and imaging features with other common lesions at this site such as benign lipoma, mucus retention cysts, fibrovascular/ inflammatory polyp and epithelial malignancies extending from adjacent anatomical structures. The two closest mimickers in laryngeal region, atypial lipoma and well differentiated liposarcoma are very difficult to differentiate on laryngoscopic examination and radiological investigations. Dedifferentiation; a poor prognostic histological feature can rarely occur after multiple recurrences but liposarcoma with de novo de-differentiation in larynx is very rare. Herein, we describe a case of liposarcoma with de novo de-differentiation originating from vallecula in a 66 years old male with review of literatures. [ABSTRACT FROM AUTHOR]

This observational study aimed to evaluate the impact of intensity of radiological surveillance on survival following resection of retroperitoneal sarcoma. Retrospective cohort study of patients undergoing primary resection of soft tissue sarcoma arising in the retroperitoneum, abdomen or pelvis at a single, high-volume sarcoma centre. Intensity of follow-up regimes up to 5 postoperative years were categorized as 'European Society for Medical Oncology (ESMO) compliant' (intense), or 'non-ESMO compliant' (less-intense). The primary outcome measure was overall survival (OS). The secondary outcome measures were disease-free survival (DFS) and reoperation rate. Analyses were stratified by high (grade 2 or 3) or low (grade 1) tumour grade. Of 168 patients, 67.1% had high-grade and 32.9% had low-grade disease. Overall, 40.0% of patients had ESMO-compliant radiological follow-up (high-grade:25.7%, low-grade:66.7%). 41.7% of patients died and 48.2% suffered local or distant recurrence by cessation of follow up. Upon univariable analysis for high-grade tumours, ESMO compliance reduced DFS (p = 0.066) but had no impact on OS. There was no significant difference in the reoperation rate in patients with ESMO-compliant and non-compliant follow-up (p = 0.097). In low-grade tumours, ESMO compliance significantly reduced DFS (p < 0.001), but without effecting OS. In risk-adjusted models for high-grade tumours, ESMO compliant follow-up was associated with reduced OS (HR:3.47, 1.40–8.61, p = 0.007) and no difference in DFS. In low-grade tumours, there was no association between overall ESMO compliance and OS or DFS. This study did not find a benefit for high-intensity radiological surveillance and overall survival in patients undergoing primary resection for high or low-grade retroperitoneal sarcoma. [ABSTRACT FROM AUTHOR]

Objective: We sought to define the prognostic significance of histologic subtype for extremity/truncal liposarcoma (LPS). Background: LPS, the most common sarcoma, is comprised of 5 histologic subtypes. Despite their distinct behaviors, LPS outcomes are frequently reported as a single entity. Methods: We analyzed data on all patients from a single-institution prospective database treated from July 1982 to September 2017 for primary, nonmetastatic, extremity or truncal LPS of known subtype. Clinicopathologic variables were tested using competing risk analyses for association with disease-specific death (DSD), distant recurrence (DR), and local recurrence (LR). Results: Among 1001 patients, median follow-up in survivors was 5.4 years. Tumor size and subtype were independently associated with DSD and DR. Size, subtype, and R1 resection were independently associated with LR. DR was most frequent among pleomorphic and round cell LPS; the former recurred early (43% by 3 years), and the latter over a longer period (23%, 3 years; 37%, 10 years). LR was most common in dedifferentiated LPS, in which it occurred early (24%, 3 years; 33%, 5 years), followed by pleomorphic LPS (18%, 3 years; 25%, 10 years). Conclusions: Histologic subtype is the factor most strongly associated with DSD, DR, and LR in extremity/truncal LPS. Both risk and timing of adverse outcomes vary by subtype. These data may guide selective use of systemic therapy for patients with round cell and pleomorphic LPS, which carry a high risk of DR, and radiotherapy for LPS subtypes at high risk of LR when treated with surgery alone. [ABSTRACT FROM AUTHOR]

Paratesticular liposarcoma is a rare variant of genitourinary malignancy. This malignancy accounts for less than 12 % of all liposarcomas. Approximately 200 cases of paratesticular liposarcoma have been reported. Giant paratesticular liposarcoma sizing over 10 cm is rarer, with only a few reported cases. Due to the rarity of this disease, there are no standardized guidelines regarding its incidence, diagnostic, recurrence, and treatment. A 73-year-old male came to the hospital with a painless left scrotal mass three years ago. The patient had an ultrasound examination of the left scrotal, which proved a solid mass and hypervascular on the left testicular. Abdominopelvic computed tomography (CT) showed a solid-cyst masses, size ±16,6 × 9,6 × 18,2 cm, lobulated, contrast enhancement with no sign of metastatic disease. The patient had radical orchiectomy without any complications. Histopathological and immunohistochemistry examination (Vimentin, MDM2, dan CDK4) showed well-differentiated liposarcoma. Radical orchiectomy is the best curative therapy. Adjuvant chemotherapy and radiotherapy benefit is still inconclusive. The patient had followed up for two years after surgery found no recurrent mass and metastatic. The well-differentiated type has a better prognosis but has a high incidence of local recurrence if incompletely excised. The result showed that this approach produces excellent outcomes without any relapse. Giant Paratesticular Liposarcoma is a rare condition that can be managed by radical. Long-term follow-up is importance to observe the relapse of this malignancy. • Paratesticular liposarcoma is a rare variant of genitourinary malignancy. • A complete excision might a crucial step to prevent the recurrence. • Adjuvant radiotherapy is required for unclear-margin resection. [ABSTRACT FROM AUTHOR]

• Dedifferentiated liposarcoma is a highly malignant, rapidly recurring tumor. • Dedifferentiated subtype is concerning due to aggressive behavior and rapid recurrence. • Negative margins are an essential factor for recurrence-free survival. Dedifferentiated liposarcoma is a rare, highly malignant, rapidly recurring tumor. When found in the spermatic cord, this tumor may deceptively present as an inguinal hernia, and due to its rarity, may not be readily identified. We report a case of a 46-year old man with dedifferentiated liposarcoma presenting as a slow-growing right inguinal bulge. His surgical management included ipsilateral orchiectomy and excision with wide margins. He received adjuvant focused radiation therapy. Liposarcoma of the Spermatic Cord is a rare and highly malignant tumor that rapidly recurs. Therefore, a high degree of suspicion, regular surveillance and imaging are justified. [ABSTRACT FROM AUTHOR]

In front of a primary retroperitoneal tumour, it is necessary to have in mind all possible diagnoses in order to specify the diagnostic strategy and the treatment. According to the World Health Organization (WHO) classification of tumours, mesenchymal benign and malignant tumours (including sarcomas and, currently, neurogenic tumours), parasympathetic tumours, extragonadal germ cell tumours, and lymphoid tumours have been identified. By definition, primary retroperitoneal tumours start independently from the retroperitoneal organs. Secondary lesions, carcinoma metastasis, and adenopathy are excluded from this definition, but they can also develop in the retroperitoneal space and lead to misdiagnoses. In the absence of positive tumour markers or an evocative biology, percutaneous biopsy is necessary. Pathological diagnosis is necessary to decide whether surgery must be done, its timing among the other treatments, and its extension. This paper summarizes all the diagnostic possibilities. - Retro- and infraperitoneal tumours: Percutaneous biopsy is the standard of care. In fact, the indications for and extent of surgery depends on the diagnosis. - Both the early complication rate and the incidence of needle tract seeding of per cutaneous biopsy of an RP mass are very low. - The well-differentiated components of liposarcomas are often underestimated, leading to incomplete surgery, which definitely worsens prognosis. - The surgical standard of care for sarcoma is a complete, non-fragmented, en bloc resection with clear margins on the larger surface. Typical resection is a compartmental surgery, with en bloc resection of the kidney, colon, and psoas fascia. Adjustments are made according to the histological subtype. - Sarcoma surgery must be performed in a referral sarcoma centre. [ABSTRACT FROM AUTHOR]

Liposarcoma (LPS) is a one of the most commonly diagnosed soft tissue sarcomas. Little is known about the epidemiology and prognosis of each subtype. We present an analysis of epidemiology and survival of the subtypes of LPS using a national database. We queried the Survival Epidemiology, and End Results (SEER) and the Canadian Institute for Clinical Evaluative Sciences (ICES) databases for data on 7 types of LPS. Pearson's chi square was used to determine associations between variables and subtypes. Kaplan-Meier and Cox Regression analyses were performed for two tests: one using SEER data and the other using variables common to both SEER and ICES. The well-differentiated subtype was the most common subtype identified. Metastatic disease was associated with decreased survival across all subtypes and age >35 was associated with decreased survival in well-differentiated and myxoid subtypes. Tumor grade was associated with decreased survival in the well-differentiated, myxoid, mixed, and round cell subtypes. In the secondary analysis, age >35 was associated with decreased survival in the myxoid subtype. The prognosis of liposarcoma differs greatly by subtype. Clinicians should account for patient factors at the time of diagnosis to best navigate treatment of their patients. [ABSTRACT FROM AUTHOR]

• Liposarcomas typically presents as bulky heterogeneous solid lesions that are larger/firmer than simple "cord lipoma." Tumors range from 3 to 30 cm in diameter. • Current controversy in management of liposarcomas pertains to the use of adjuvant chemotherapy or radiotherapy and whether these treatment options decrease recurrence/survival. • We recommend an initial complete resection with wide margins without the use of adjuvant therapy with aggressive long-term surveillance. • Based on extrapolated data from studies pertaining to sarcomas of the extremities, adjuvant radiation or chemotherapy may serve a role but further research is crucial. Malignant spermatic cord tumors have an annual incidence of 0.3 cases/million. The vast majority of tumors in this region are benign. We present a rare case of a dedifferentiated liposarcoma of the spermatic cord successfully treated. A 59-year-old gentleman presented complaining of an enlarging painful right groin mass. On exam there was an obvious 10 cm inguinal mass. Imaging illustrated a right inguinal soft tissue mass that was not present on imaging 22 months prior. The patient underwent a right inguinal exploration, en bloc resection of the mass, and radical orchiectomy to ensure negative margins. Histopathological analysis revealed a grade 2 dedifferentiated liposarcoma that measured 9 × 6 × 5 cm, with 5 cm negative margins. The patient did well and was discharged on postoperative day one. On 6-month follow-up there was no evidence of recurrence. We present a rare dedifferentiated liposarcoma of the spermatic cord that was successfully treated with surgical resection. This case highlights the importance of maintaining a high index of suspicion coupled with a thorough history and physical examination when encountering an enlarging inguinal mass. This rare pathology is lacking level one evidence-based standardized treatment algorithms. The mainstay of treatment is surgical resection. For spermatic cord liposarcomas, the surgical approach is en bloc resection with radical orchiectomy aiming for R0 margins. Prognosis depends on tumor grade, anatomic site, and the ability to achieve a microscopically tumor negative resection. Despite our patient's disease free status, prolonged surveillance with physical examination and cross sectional imaging is still warranted. [ABSTRACT FROM AUTHOR]

In retroperitoneal soft tissue sarcoma (STS) local recurrence (LR) rates remain high despite more aggressive surgical approaches. Since wide resection margins cannot be achieved in all patients, application of intraoperative radiation therapy (IORT) has been frequently discussed. Still, the significance of IORT in multimodal treatment of retroperitoneal STS remains unclear. Patients undergoing resection of primary or recurrent retroperitoneal STS at the University of Heidelberg Department of General, Visceral and Transplantation Surgery were retrospectively analyzed. Univariate Kaplan-Meyer and multivariate Cox regression analyses were performed to identify predictors of LR-free survival and to investigate the impact of IORT and high cumulative radiation doses. Analyses with propensity-score matched subgroups for IORT and cumulative radiation dose were performed to control for selection bias. Subgroup analyses for patients with retroperitoneal liposarcoma were likewise performed. 272 patients were identified. Recurrent tumors, histology of dedifferentiated liposarcoma or unclassified sarcoma and microscopically incomplete resection were associated with decreased LR-free survival. In liposarcoma, only recurrent and dedifferentiated tumors were confirmed as poor prognostic factors concerning LR. IORT and cumulative radiation doses exceeding 60 Gy did not influence LR rates (estimated 5-year LR-free survival: IORT: 39%, non-IORT: 46%; p = 0.79). In this retrospective evaluation, additional application of IORT does not significantly influence oncological outcome in retroperitoneal soft tissue sarcoma. Randomized trials are needed to clarify the benefit of IORT. [ABSTRACT FROM AUTHOR]

• Sciatic hernias are very rare. • Lipomatous tumors herniating through the sciatic foramen have only been documented in 6 cases. • CT and MRI imaging of the abdomen and pelvis facilitate diagnosis and appropriate surgical treatment. • Documented findings add to the current literature and will guide appropriate treatment in future cases. Lipomatous tumors herniating through the sciatic foramen are extremely rare with less than 6 cases reported in the existing literature. We report a case of gluteal well differentiated liposarcoma that presented as sciatic hernia. A 66-year-old female presented with persistent pain in the right gluteal region. Physical examination coupled with CT/MRI scans identified a firm mass extending into the right pelvic side via the sciatic foramen. It measured approximately 18.9 cm × 13 cm × 22.8 cm. The tumor was resected via transgluteal approach. Immunohistochemical and microscopic features were consistent with well-differentiated liposarcoma. Although sciatic hernias associated with intraabdominal contents have been recorded less than 100 times in the literature, instances where gluteal lipomatous tumors manifest as sciatic hernias are even more rare. In this case the gluteal liposarcoma was successfully identified utilizing CT/MRI scanning followed by a transgluteal excision of the mass. While sciatic hernias are rare, lipomatous/liposarcomatous tumors presenting as sciatic hernias are extremely rare. This case report highlights a combination of rare phenomena. The information presented adds to the current evidence that will guide accurate diagnosis and appropriate treatment of future cases. [ABSTRACT FROM AUTHOR]

• Complete surgical resection of liposarcoma is central in treatment based on grade. • Radiation reduces risk of local recurrence or minimize surgical morbidity in the highly radiosensitive myxoid/round cell liposarcoma group. • Chemotherapy is utilized in chemosensitive histologies with metastatic potential. • Understanding of the genetic aberrations allows development of targeted therapies for liposarcoma. Multifocal soft tissue sarcoma is a rare clinical entity occurring in 1 % of patients with extremity soft tissue sarcoma and in 4.5 % of patients with liposarcoma. Multifocal disease may arise either synchronously or metachronously and has been associated with poor prognosis. Herein, we report a rare case of a Syrian woman patient with six different foci of liposarcoma in five sites at the time of diagnosis. Liposarcomas are currently classified into four different subtypes based on histologic or genetic analysis according to the World Health Organization (WHO), including cell-differentiated, dedifferentiated, myxoid, and pleomorphic. In the present work, we report a neglected patient with a multicentric round cell liposarcoma in five different sites. Medicine cannot provide much care for these advanced cases of multicentric liposarcoma so far. Therefore, more research should be conducted to improve the ability to manage these entities and to identify potential novel therapies. [ABSTRACT FROM AUTHOR]

Tumor location as a prognostic factor for patients with liposarcoma (LPS) has been studied modestly with varying outcomes. The aim was to establish the impact of tumor location on recurrence and survival of LPS patients. A retrospective database of patients treated for LPS until December 2017 was used to assess 5-year local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and disease-specific survival (DSS) per tumor location using the Kaplan-Meier method and log-rank test. A multivariable Cox regression analysis was performed to adjust for other prognostic factors. In total, 518 patients were identified with a median follow-up of 68 months (interquartile range 31–138). Patients with retroperitoneal/intrathoracic WDLPS or DDLPS (p = 0.014), or testicular WDLPS (p = 0.026) developed a local recurrence more often than patients with other tumor locations. No differences between LPS subtypes and tumor location in the development of metastases (p = 0.600) was observed. Five-year LRFS differed significantly between tumor locations (p < 0.001) as well as 5y-DSS (p < 0.001), but 5y-DMFS did not (p = 0.241), with retroperitoneal/intrathoracic LPS having a worse prognosis. Patients with WDLPS in the extremity, trunk or testicular region did not die of disease, except for the rare occasion of dedifferentiation upon recurrence. After adjustment for other prognostic factors, tumor location was only of prognostic value for DSS (retroperitoneal/intrathoracic vs. extremity: HR 5.08, 95% CI 2.41–10.71, p < 0.001). For all tumor locations, DSS mimicked DMFS except for retroperitoneal/intrathoracic LPS, where DSS mimicked LRFS and where DSS was worse than DMFS. This implies that these patients die of local disease instead of metastatic disease. [ABSTRACT FROM AUTHOR]

Myxoid Round cell containing myxoid liposarcomas (MRCLS) have a high propensity to metastasize to soft tissue and bone. Whole Body Magnetic Resonance Imaging (BMRI) has been reported as a critical modality to early detect disease spreading in asymptomatic patients. The purpose of this study is to describe metastatic patterns and outcomes in patients through annual BMRI surveillance after diagnosis of MRCLS of the extremities and trunk. This retrospective study included patients with histology confirmed MRCLS. Initial BMRI were done within 6 months following the first line treatment then once a year. Forty-five out of 51 consecutive MRCLS patients were included. At the last follow-up 10 patients (22.2%) had an extra-pulmonary soft-tissue or/and bone metastasis detected in a median delay of 22.7 ± 16 months [0−49] from the diagnosis of the MRCLS. Nine patients were asymptomatic. Finally, 5-years metastatic free survival was 72 ± 8%. All metastatic patients had multiple lesion within the year following the first lesion diagnosis. Systematic BMRI in MRCLS patients following treatment frequently identify extra-pulmonary metastasis in asymptomatic patients within the first 5 years of follow-up. Despite a long survival can be expected after diagnosis, extra-skeletal metastasis was a signal of disseminated disease. [ABSTRACT FROM AUTHOR]

The incidence of lipoblastoma is low, with fetal occurrences being even rarer. There are very few prenatal reports about lipoblastoma. We present a case report of fetal perineal lipoblastoma, which was confirmed by pathology after birth. In this case, the combination of three-dimensional(3D) ultrasound greatly improved the diagnostic accuracy by determining the location and shape of the mass. Combining 3D ultrasound imaging with specific ultrasound characteristics related to different masses significantly enhances diagnostic accuracy for lipoblastomas during prenatal examinations. This case report provides valuable insights for prenatal diagnosis and counseling of lipoblastoma. [ABSTRACT FROM AUTHOR]

• MDM2 and CDK4 alterations are known mutations in some liposarcomas. • Both are also hallmarks of well-differentiated and dedifferentiated liposarcomas. • These alterations are associated with oncogenesis and disease progression. • Clinical trials in liposarcoma are investigating agents targeting MDM2 and CDK4. Well-differentiated and dedifferentiated liposarcomas (WDLPS and DDLPS) are rare tumors that arise from lipocytes in soft tissue. There is a high unmet need in patients with these liposarcomas given poor outcomes, particularly for DDLPS. WDLPS and DDLPS share important genetic and histological characteristics – most notably, the amplification of the 2 genes MDM2 and CDK4. Both genes are considered oncogenes because of their ability to shut down tumor suppressor pathways. There are multiple therapeutic approaches that aim to target MDM2 and CDK4 activity for the purpose of restoring intrinsic tumor suppressor cellular response and terminating oncogenesis. However, current understanding of the molecular mechanisms involved in WDLPS and DDLPS pathology is limited. In recent years, significant efforts have been made to refine and implement targeted therapy for this patient population. The use of patient-derived cell and tumor xenograft models has been an important tool for recapitulating WDLPS and DDLPS biology. These models also offer valuable insights for drug development and drug combination studies. Here we offer a review of the current understanding of WDLPS and DDLPS biology and its therapeutic implications. [ABSTRACT FROM AUTHOR]

• Systematic review using PICO model to determine the role of perioperative chemotherapy in retroperitoneal sarcoma. • Search identified 23 studies (22 retrospective studies, one meta-analysis) • No evidence that the addition of chemotherapy to surgery improves recurrence free survival or overall survival in resectable RPS. In primary localised resectable retroperitoneal sarcoma (RPS), loco-regional and distant relapse occur frequently despite optimal surgical management. The role of chemotherapy in improving outcomes is unclear. A systematic review was conducted, using the population, intervention, comparison outcome (PICO) model, to evaluate whether neoadjuvant or adjuvant chemotherapy improve outcomes in adults with primary localised resectable RPS. Medline, Embase and Cochrane Central were queried for publications from 1946 to June 2022 that evaluated recurrence free survival, overall survival, and post operative complications. Each study was screened by two independent reviewers for suitability. A qualitative synthesis of the results was performed. Twenty three studies were identified; one meta -analysis of retrospective studies and 22 retrospective studies including three with propensity matched cohorts. Most studies did not analyse outcomes by histology, detail treatment regimens, provide baseline characteristics or selection criteria for those receiving chemotherapy. Evidence of selection bias was illustrated in several studies. Newcastle-Ottawa quality of retrospective cohort studies was good for 12 studies and poor for 10 studies. All studies were assessed as Level III-2 evidence by the Australian NHMRC hierarchy. Overall, the addition of neoadjuvant or adjuvant chemotherapy to surgery was not associated with improvement in local recurrence, metastasis free survival, disease free survival or overall survival in primary localised resectable RPS. There is some evidence of an association of chemotherapy with worse overall survival. One single centre study showed that neoadjuvant chemotherapy was not associated with increased post operative complications compared to surgery alone in primary localised resectable RPS. There is currently no evidence that demonstrates the addition of chemotherapy to surgery improves outcomes in adult patients with primary localised resectable RPS. Available evidence is limited by its retrospective nature and high likelihood of selection bias with chemotherapy generally administered to patients at higher risk of recurrence and many patients not receiving care in high volume sarcoma centres. Randomised trials are required to conclusively determine the role of chemotherapy in primary localised resectable RPS. [ABSTRACT FROM AUTHOR]

High rates of local recurrence (LR) have been reported following resection of extremity Atypical lipomatous tumours/Well-differentiated liposarcomas (ALTs). This retrospective study of patients who underwent resection of primary deep extremity and trunk ALTs at a specialist sarcoma centre aims to assess morbidity and factors associated with low local recurrence rates (LRR). To review a homogeneous cohort of patients with low-grade disease, tumours with known high-risk histological features were excluded. Prognostic variables potentially influencing local recurrence (LR) (age, size, site, margin status, and histological findings) were analysed. Endpoints were LR, distant recurrence (DR) and local disease-free survival (LDFS). 127 patients were identified, with median follow-up of 54 months (0–235). Median tumour size was 17.5 cm (5–36). 85 % occurred in the lower limb. 93.7 % underwent marginal resection. No patients received radiotherapy. Median hospital stay was 3 days (0–16). 7.9 % returned to theatre for evacuation of haematoma or infected seroma and 18.1 % had outpatient seroma aspiration. Surgical margins were R0/R1 in 93.7 % of patients and R2 in 6.3 % with a LR rate of 8.4 % and 75 % respectively at median time of 54 months. One- and 5-year LDFS was 100 % and 88.4 %, respectively. DR rate was 0.8 % (1/127) this patient had pleomorphic liposarcomatous transformation on recurrence and subsequently developed distant metastases. No patients died of disease. Function-preserving marginal resection of non-coelomic ALTs has low morbidity, low LR and extremely low rates of distant relapse. Patients with lower limb ALT were found to have significantly lower LR, which may impact follow-up protocols. [ABSTRACT FROM AUTHOR]

Histologic subtype of cancer guides treatment sequencing and the extent of surgery for retroperitoneal tumours (RPTs) but concerns persist regarding percutaneous core needle biopsy (CNB). Endpoints were the incidence of early complications, needle tract seeding (NTS) after CNB, diagnostic accuracy. Between 2015 and 2022, data from patients with RPT who underwent a CNB and who operated on at Institut Curie were collected. We retrospectively reviewed the medical records and microscopic analysis of both CNB and surgical specimens to evaluate the diagnostic accuracy of CNB (quantified using positive and negative predictive values, PPV/NPV). 313 patients underwent CNB. In 10/326 (3 %) procedures, minor complications were observed. One of 212 (0.47 %) resected RPSs exhibited a local recurrence compatible with NTS. Microscopic analysis of CNB specimens allowed the classification of tumours between groups of cancers and benign/intermediate mesenchymal tumours in 307/313 (98 %) patients. Among the 204 patients with retroperitoneal sarcoma, the overall concordance between CNB and final pathology following resection was 178/204 (87.2 %). The respective PPVs of solitary fibrous tumour, dedifferentiated liposarcoma, leiomyosarcoma and well-differentiated liposarcoma were 100 %, 98 %, 97 % and 68 %, respectively. The diagnosis of a high-grade (G 2-3) sarcoma resulted in a high specificity (97 %) and PPV (98 %) but low sensitivity (76 %). CNB allowed the classification of RPT in the vast majority of patients with a low morbidity rate. Concordance with final diagnosis was high for sarcomas with the exception of well-differentiated liposarcoma. As a result, CNB results should be integrated with imaging/radiomics by multidisciplinary tumour boards. [ABSTRACT FROM AUTHOR]

Liposarcoma is one of the most common mesenchymal neoplasms in adults. Among liposarcomas, gastrointestinal tract involvement is uncommon, and liposarcoma of the stomach is a particularly rare entity, In addition, few cases of gastric liposarcoma with malignant transformation from benign gastric lipoma have been reported. Here we present the case of a 62-year-old male patient who was diagnosed with gastric liposarcoma and managed with laparoscopic surgical resection. He was first diagnosed with subepithelial lipoma of the stomach 4 years ago and was under observation, but underwent laparoscopic distal gastrectomy due to malignant transformation of gastric lipoma. He has been following up for 1 year after surgery, and there are no recurrence or other complications to date. This patient was initially diagnosed with gastric lipoma and was surgically resected after 4 years of observation to show malignant transformation. To the best of our knowledge, this case represents the first report of gastric lipoma demonstrating malignant transformation into gastric liposarcoma. Gastric lipoma can be transformed into gastric liposarcoma, so if the size is large or the rate of size change is fast, surgical resection is recommended in the early state, and en-bloc resection including node dissection and reconstruction are desirable during surgery. • Gastric liposarcoma is a very rare entity. • Gastric liposarcoma can be transformed from the gastric lipoma • It is important to conduct follow-up assessments while considering the possibility of gastric liposarcoma. [ABSTRACT FROM AUTHOR]

In this study, we present six cases of epithelioid dedifferentiated liposarcoma to further characterize its clinical and pathological features. The patients are all adult men with age at presentation ranging from 46 to 64 years (median 58.5 years). The patients presented with nonspecific symptoms of retroperitoneal mass, intermittent dull pain or discomfort. None of the patients had any prior history of a primary tumor. Radiological examinations revealed the presence of ill-demarcated heterogenous mass located in the deep soft tissue, including retroperitoneum (4 cases), pelvis and trunk (1 case each). Grossly, they appeared as solid tumors with focal areas of necrosis being presented in 2 cases. Histologically, all tumors were characterized by sheets of epithelioid cells that displayed marked cellular atypia and brisk mitotic activity. Variable portion of atypical lipomatous tumor/well-differentiated liposarcoma was present in 3 cases. By immunohistochemistry, the high-grade epithelioid component in all 6 cases showed strong and diffuse nuclear staining of MDM2, CDK4 and P16, with partial expression of AE1/AE3 in 3 cases. Fluorescence in situ hybridization analysis revealed high-level amplification of MDM2 in all 6 cases, with co-amplification of CDK4 in 3 cases. Follow up information showed that two patients died of the disease within one year despite multidisciplinary treatment. Due to the striking epithelioid appearance, this rare variant of dedifferentiated liposarcoma may be confused with undifferentiated epithelioid sarcoma, poorly differentiated carcinoma, mesothelioma or other malignancies with epithelioid phenotype. The study presented herein further highlights the aggressive clinical behavior of this unique tumor type. For patients with advanced disease, CDK4 inhibitor may provide an optional targeted treatment. • Epithelioid differentiated liposarcoma represents an underrecognized novel variant. • Showing a predilection for the retroperitoneum of middle to old aged males • Immunostaining and FISH test for MDM2 and CDK4 are essential for the diagnosis. • Biologically characterized by a high rate of recurrence, metastasis and mortality • The provisional targeted therapy of CDK4 inhibitor remains to be further investigated. [ABSTRACT FROM AUTHOR]