Management of myxoid liposarcoma of the extremity

"Enhancing Liposarcoma Prognosis - A New Predictive Scoring System Integrating Histopathological Insights"

Introduction

Liposarcomas are malignant soft tissue tumours with heterogeneous features and variable prognosis. Each entity comprised in this group displays distinct morphology and harbours specific genetic alterations, which correlate with clinical behaviour and therapy response. The aim of this study is to analyse the clinical and histopathological features that can influence the prognosis of liposarcoma. We also present a newly designed scoring system that could be useful for predicting the risk of disease progression and death in patients with different liposarcoma subtypes.

Materials and Methods

We carried out a retrospective multicentric study on 77 liposarcomas diagnosed between 2009 and 2023 that were followed up to assess the presence of metastases and survival of the patients. We evaluated the age, gender, tumour location and dimensions, histological subtype, mitotic index, presence and percentage of necrosis, and their association with disease progression and survival.

Results

In this respect, progression-free survival was positively associated with lower mitotic index, somatic soft-tissue localization, well-differentiated and myxoid subtypes and absence of necrosis. Overall survival was negatively influenced by older age, higher mitotic index, dedifferentiated and pleomorphic subtypes and the presence of necrosis. Therefore, several clinical and histopathological features of liposarcomas, such as tumour location, mitotic index, and tumour necrosis can strongly predict the disease evolution.

Discussion

This study focuses on developing a new scoring system that considers histologic subtype, mitotic index, and tumour necrosis as indicators that could predict the risk of disease progression and overall survival in patients with liposarcoma. The system classifies liposarcomas of any histological subtype into low-risk and high-risk tumours. Diagnosing liposarcomas using this two-tiered system could be useful for providing personalized therapy, in order to avoid relapses, metastases and improve the disease's prognosis.

Histology-Tailored Approach to Soft Tissue Sarcoma

Soft tissue sarcomas are a diverse and heterogeneous group of cancers of mesenchymal origin. Each histological type of soft tissue sarcoma has unique clinical particularities, which makes them challenging to diagnose and treat. Multidisciplinary management of these rare diseases is thus key for improved survival. The role of surgery has been well established, and it represents the cornerstone curative treatment for soft tissue sarcomas. To date, local recurrence is the leading cause of death in low-grade sarcomas located at critical sites, and distant metastasis in high-grade sarcomas, regardless of the site of origin. Management must be tailored to each individual histologic type. We describe the most common types of extremity, trunk, abdominal, and retroperitoneal soft tissue sarcoma along with characteristics to consider for optimized management.

Myxoid Liposarcomas of the Thigh: Pre-Operative Presentation, Clinical Outcomes, and Functional Results of Surgical Treatment

Myxoid liposarcomas are malignant soft-tissue sarcomas whose treatment represents a challenge, even for the most experienced surgeon. In this study, we report on our experience with the treatment of myxoid liposarcomas of the thigh. Our retrospective analysis included myxoid liposarcomas of the thigh treated with surgical resection between 2016 and 2022. Resection margins, complications, local recurrences, and metastases were recorded. The oncological outcome of each case was evaluated at their latest follow-up. Adjuvant therapies were administered according to the ESMO guidelines. Functionality was assessed with the MSTS score before surgery and at the patients' latest follow-up. Thirty cases (ten high-grade and 20 low-grade) were included. The mean diameter was 11.8 cm. Twenty-four cases had wide margins (80%) and six (20%) were marginal. Five cases (60% marginal) had local recurrences (17%). Marginal resection was associated with a higher risk of local recurrence (p = 0.041). Three cases with high-grade tumors (10%) developed metastases. At the patients' latest follow-up, their mean MSTS score had risen from 22.9 to 27.3. While tumor grade influences the risk of metastases, the quality of resection margins can determine the local recurrence rate. An adequate surgery can lead to good post-operative functional outcomes.

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

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

Pseudocystic myxoid liposarcoma of the posterior chest wall - a rare case report

Introduction and importance

Liposarcoma (LPS) is a common soft-tissue sarcoma predominantly diagnosed in adults, arising from malignant adipose cells. Among its various subtypes, myxoid LPS (MLPS) stands out as the second most frequent, accounting for ~30% of all LPS cases. This particular subtype typically manifests in males between the ages of 40 and 50 and is commonly found in the lower extremities. Although rare, MLPS may also occur in the head, neck, and infrequently in the back. Chest wall LPS cases are also sparsely reported.

Case presentation

In this report, we present a case of MLPS in a 69-year-old male patient who presented with a complaint of firm swelling on the right posterior chest wall, which was progressively increasing in size over the past 10 years. The tumour was located in the posterior chest wall on the left side, and further diagnostic evaluation using computed tomography (CT) and MRI was conducted to identify its characteristics and extent.

Clinical discussion

The use of CT scanning plays a crucial role in differentiating between various lipomatous tumour types, aiding in the identification and classification of MLPS. However, MRI emerges as a more effective technique for detecting microscopic fat compared to CT or ultrasonography, providing valuable insights for accurate diagnosis and treatment planning.

Conclusion

Surgery remains the primary therapeutic approach for managing LPSs, including MLPS. Adjuvant preoperative radiation is recommended due to its significant sensitivity and potential for improved outcomes. Given the rarity of this presentation and the varied anatomical locations, a multidisciplinary approach is paramount in effectively managing such cases. Medical practitioners should collaborate closely, considering the unique challenges posed by MLPS to ensure optimal patient care and treatment outcomes.

Survival of a patient with five recurrences of retroperitoneal liposarcoma over a period of 13 years: A case report and review

Retroperitoneal liposarcoma (RPLS) is a rare tumor that occurs in the retroperitoneal region and accounts for ~0.2% of all malignant tumor incidence. The present study describes the treatment of a surviving patient with RPLS that recurred five times in 13 years. This case has a long survival time and numerous relapses, which is a rare occurrence. The 40-year-old female patient was admitted to Shaoxing Second Hospital (Shaoxing, China) with an abdominal mass. Abdominal computed tomography (CT) scan revealed multiple liposarcoma recurrences in the abdominal, pelvic and retroperitoneal areas. As the diagnosis of RPLS was the fifth recurrence, cytoreductive surgery was performed and post-operative pathology suggested mixed liposarcoma. The patient underwent six cycles of doxorubicin and ifosfamide regimen chemotherapy and targeted therapy with anlotinib following surgery; no evidence of disease progression was found on abdominal CT scan during follow-up. The present study also reviewed the literature in terms of the clinical diagnosis, treatment, pathological characteristics and similar cases of liposarcoma with the aim of improving diagnosis and treatment.

Primary renal myxoid liposarcoma with pancreatic invasion on 18F-FDG PET/CT: first case report and literature review

Background

Myxoid liposarcoma (MLS) is a rare malignant soft tissue sarcoma that predominantly manifests in the deep soft tissues of the extremities, particularly within the musculature of the thigh. Unlike other types of liposarcoma, MLS demonstrates a propensity for metastasis to atypical sites, including the lung parenchyma, soft tissues, retroperitoneum, mediastinum, breast, liver, thymus, lymph nodes, and bones. The definitive diagnosis primarily relies on histology with HE staining. Imaging modalities such as ultrasound, CT, MRI, and 18F-FDG PET/CT scans serve as valuable tools for tumor identification.

Case report

A 57-year-old man presented with symptoms of abdominal distention and vomiting 1 month ago. Contrast-enhancement CT revealed a heterogeneous hypodense mass in the upper-middle part of the left kidney, displaying irregular morphology and protrusion towards the exterior of the kidney, with abundant blood supply and had a maximum dimension of approximately 10.7 cm × 9.0 cm. Additionally, a rounded soft tissue density was identified in the pancreatic body. Multiplanar reconstruction demonstrated a connection between the pancreatic lesion and the kidney mass. 18F-FDG PET/CT was conducted for staging, revealing significant growth of the lesion in the upper-middle part of the left kidney, extending beyond the kidney and infiltrating the pancreatic body. The lesion demonstrated remarkably high 18F-FDG uptake (SUVmax = 10.2, MTV = 136.13 cm3, TLG = 484.62). The postoperative pathological examination confirmed the diagnosis of MLS. On the 10th day post-surgery, the patient presented with tumor recurrence and underwent another surgical resection. Unfortunately, during the operation, the patient experienced a sudden cardiac arrest and died.

Conclusion

Renal MLS with invasion into the pancreas is very rare in clinical practice. Due to the limited research on the utilization of 18F-FDG PET/CT in this particular context, given the rarity and low incidence of MLS, its role remains largely unexplored. As PET/CT imaging becomes increasingly prevalent, thorough imaging of disease sites becomes indispensable for the development of treatment protocols and the monitoring of treatment response.

Case report: Atypical spindle cell/pleomorphic lipomatous tumor masquerading as a myxoid liposarcoma or intramuscular myxoma

Atypical spindle cell/pleomorphic lipomatous tumors (ASPLTs) were recently categorized as benign lipomatous tumors. However, accurate and complete preoperative diagnosis of ASPLTs may be difficult. Furthermore, diagnosis based on magnetic resonance imaging (MRI) findings is uncertain because of the varying ratios of the fat component within the tumor. Here, we report a case of ASPLT masquerading as a myxoid tumor. Although MRI findings were consistent with a myxoid liposarcoma, needle biopsy findings suggested a myxoma, and we performed marginal resection. Histopathological findings revealed infiltrating spindle cells with atypia. In addition, immunohistochemistry (IHC) showed positive staining for CD34 and heterogeneous retinoblastoma deficiency, and fluorescence in situ hybridization (FISH) showed no amplification of mouse double minute 2 homolog and no rearrangement of FUS or EWSR1. When MRI and histopathological findings suggest a myxoid tumor, IHC and FISH should be considered and performed for a precise and accurate diagnosis.

Targetable Pathways in the Treatment of Retroperitoneal Liposarcoma

Liposarcoma (LPS) is the most prevalent soft tissue sarcoma histological subtype. When it occurs in the abdomen the overall survival rate is as low as 10% at 10 years and is fraught with high rates of recurrence, particularly for the more aggressive dedifferentiated subtype. Surgery remains the mainstay of treatment. Systemic therapies for the treatment of metastatic or unresectable disease have low response rates. Deep understanding of well-differentiated and de-differentiated LPS (WDLPS and DDLPS, respectively) oncologic drivers is necessary for the development of new efficacious targeted therapies for the management of this disease. This review discusses the current treatments under evaluation for retroperitoneal DDLPS and the potential targetable pathways in DDLPS.