Retroperitoneal liposarcoma: a comprehensive review. Am J Clin Oncol. 2015;38:213-219. [PMID: 24136142 DOI: 10.1097/coc.0b013e31829b5667]

Combination of eribulin and anlotinib exerts synergistic cytotoxicity in retroperitoneal liposarcoma by inducing endoplasmic reticulum stress

Primary retroperitoneal liposarcoma (RLPS) is a rare heterogeneous tumor occurring within retroperitoneal space, and its overall survival has not improved much in the past few decades. Based on a small-sample clinical practice at our center, patients with RLPS can greatly benefit from anlotinib and eribulin combination. In this study, we investigated the combinational effect of anlotinib and eribulin on RLPS. In vitro experiments revealed that a low dose of anlotinib significantly enhances the cytotoxic effects of eribulin, leading to a remarkable suppression of RLPS cell proliferation, viability, colony formation, migration, and cell-cycle progression compared to individual drug treatments. At the organoid level, the combination treatment causes the spheroids in Matrigel to disintegrate earlier than the single-drug group. In vivo, RLPS patient-derived xenograft (PDX) models demonstrated that the combination of these two drugs can obviously exert a safe and effective anti-tumor effect. Through transcriptome analysis, we uncovered and validated that the synergistic effect mainly is induced by the endoplasmic reticulum stress (ERS) pathway both in vitro and in vivo. Further analyses indicate that anlotinib plus eribulin treatment results in micro-vessel density and PD-L1 expression alterations, suggesting a potential impact on the tumor microenvironment. This study extensively explored the combination regimen at multiple levels and its underlying molecular mechanism in RLPS, thus providing a foundation for translational medicine research.

A rare presentation of retroperitoneal liposarcoma presented with jejunal intussusception: An interesting radiological findings

A jejunal intussusception as a presentation of retroperitoneal liposarcoma (RLPS) is a rare occurrence. The majority of RLPS are presented as an abdominal mass, however, having a jejunal obstruction is an interesting case. The aim is to describe the management of jejunal intussusception secondary to atypical lipomatous tumours with concurrent RLPS. A 61-year-old lady presented with a sudden onset of intestinal obstruction with 1 month of constitutional symptoms and an enlarging right lumbar mass. Computed tomography showed a small bowel intussusception with diffuse peritoneal and retroperitoneal lipomatosis. Emergency exploratory laparotomy, segmental bowel resection, and partial excision of intraperitoneal mesenteric lipoma were performed. A stage En-bloc resection of the RLPS and right nephrectomy was done later. However, she refused for subsequent surgery. A complete resection is the gold standard in managing RLPS. In this report, the management is rendered not to the standard as the patient first presented with intestinal obstruction requiring emergency reduction with a piecemeal resection. A stage surgery was required to determine a promising prognosis, but the patient refused such surgery. A small bowel intussusception in adults is rare but is mostly caused by a tumor or neoplasm. Early recognition of the complexity of the case should be preempted and referred to the tertiary team for further definitive surgery. Patient exhaustion from the subsequent surgery might hamper the only management available for the case.

Comprehensive Analysis of a Six-Gene Signature Predicting Survival and Immune Infiltration of Liposarcoma Patients and Deciphering Its Therapeutic Significance

BACKGROUND

As a common soft tissue sarcoma, liposarcoma (LPS) is a heterogeneous malignant tumor derived from adipose tissue. Due to the high risk of metastasis and recurrence, the prognosis of LPS remains unfavorable. To improve clinical treatment, a robust risk prediction model is essential to evaluate the prognosis of LPS patients.

METHODS

By comprehensive analysis of data derived from GEO datasets, differentially expressed genes (DEGs) were obtained. Univariate and Lasso Cox regressions were subsequently employed to reveal distant recurrence-free survival (DRFS)-associated DEGs and develop a prognostic gene signature, which was assessed by Kaplan-Meier survival and ROC curve. GSEA and immune infiltration analyses were conducted to illuminate molecular mechanisms and immune correlations of this model in LPS progression. Furthermore, a correlation analysis was involved to decipher the therapeutic significance of this model for LPS.

RESULTS

A six-gene signature was developed to predict DRFS of LPS patients and showed higher precision performance in more aggressive LPS subtypes. Then, a nomogram was further established for clinical application based on this risk model. Via GSEA, the high-risk group was significantly enriched in cell cycle-related pathways. In the LPS microenvironment, neutrophils, memory B cells and resting mast cells exhibited significant differences in cell abundance between high-risk and low-risk patients. Moreover, this model was significantly correlated with therapeutic targets.

CONCLUSION

A prognostic six-gene signature was developed and significantly associated with cell cycle pathways and therapeutic target genes, which could provide new insights into risk assessment of LPS progression and therapeutic strategies for LPS patients to improve their prognosis.

Rapid and Precise Diagnosis of Retroperitoneal Liposarcoma with Deep-Learned Label-Free Molecular Microscopy

The retroperitoneal liposarcoma (RLPS) is a rare malignancy whose only curative therapy is surgical resection. However, well-differentiated liposarcomas (WDLPSs), one of its most common types, can hardly be distinguished from normal fat during operation without an effective margin assessment method, jeopardizing the prognosis severely with a high recurrence risk. Here, we combined dual label-free nonlinear optical modalities, stimulated Raman scattering (SRS) microscopy and second harmonic generation (SHG) microscopy, to image two predominant tissue biomolecules, lipids and collagen fibers, in 35 RLPSs and 34 normal fat samples collected from 35 patients. The produced dual-modal tissue images were used for RLPS diagnosis based on deep learning. Dramatically decreasing lipids and increasing collagen fibers during tumor progression were reflected. A ResNeXt101-based model achieved 94.7% overall accuracy and 0.987 mean area under the ROC curve (AUC) in differentiating among normal fat, WDLPSs, and dedifferentiated liposarcomas (DDLPSs). In particular, WDLPSs were detected with 94.1% precision and 84.6% sensitivity superior to existing methods. The ablation experiment showed that such performance was attributed to both SRS and SHG microscopies, which increased the sensitivity of recognizing WDLPS by 16.0 and 3.6%, respectively. Furthermore, we utilized this model on RLPS margins to identify the tumor infiltration. Our method holds great potential for accurate intraoperative liposarcoma detection.

A Case of a Giant Liposarcoma at Binh Dan Hospital

Retroperitoneal liposarcomas (RLSs) are uncommon mesenchymal tumors that might present a diagnostic challenge due to their rarity and anatomical location. Despite grossly complete resections, they are commonly linked to a high recurrence rate, necessitating long-term or indefinite follow-up. This report discusses a 59-year-old male patient referred to the Gastrointestinal Department due to chronic abdominal distention, right-sided back pain, and a sizable abdominal mass. The diagnosis was an RLS, and the patient underwent en bloc resection of the mass.

A Case Report of a 17 cm Retropharyngeal Well-Differentiated Liposarcoma With Bilateral Neck Extension

Liposarcomas, malignant adipocytic tumors, primarily manifest in the lower extremities and retroperitoneum, with a strikingly low incidence in the head and neck region. Symptomatology typically remains absent until the tumor attains significant size, leading to cosmetic concerns or compression-related complications. This report presents a unique case of well-differentiated retropharyngeal liposarcoma in an 81-year-old male, emphasizing diagnostic challenges, management strategies, and the crucial role of Mouse double minute 2 (MDM2) fluorescence in situ hybridization (FISH) analysis in confirmation. The patient exhibited dysphagia attributed to a retropharyngeal mass, prompting suspicion of malignancy. Diagnostic assessments, including flexible laryngoscopy and percutaneous tru-cut biopsy, highlighted unique features such as atypical nuclear features in adipocytes. MDM2 FISH analysis definitively confirmed the diagnosis by detecting MDM2 gene amplification. The rarity of retropharyngeal liposarcomas complicates diagnosis, often leading to confusion with benign lesions. Surgical excision, the mainstay of treatment, varies based on tumor size and extension. In this case, a left neck dissection via a hockey stick incision successfully resected a 17 cm well-differentiated liposarcoma. Pathologic analysis revealed focal involvement of resection margins, with no complications or vocal cord damage. In conclusion, retropharyngeal liposarcomas pose diagnostic challenges, warranting reliance on MDM2 FISH analysis for accurate confirmation. Early surgical intervention, guided by tumor size and extension, is paramount for optimal outcomes in managing these rare tumors. This case underscores the significance of a detailed surgical approach in achieving successful outcomes for retropharyngeal liposarcomas.

Case Report: Successful R0 resection in locally advanced retroperitoneal sarcomas

We present a case series of three successfully resected tumors in our center at Al-Makassed Hospital in Jerusalem, Palestine, all of which primarily involved or invaded adjacent structures and needed a multidisciplinary approach to achieve R0 resection. Our first patient is a 42-year-old previously healthy female with intermittent attacks of dull aching abdominal pain. Her tumor was a leiomyosarcoma that involved major vessels and other adjacent vital structures. Ultimately, she needed major highly advanced surgery necessitating the need for vascular reconstruction of the IVC, as well as R0 resection. The surgery was performed by a multidisciplinary team of highly specialized surgeons in related fields. Our second case is a 75-year-old female patient with a well-differentiated liposarcoma invading the upper pole of the right kidney, necessitating a nephrectomy. Consequently, this case demanded the interdisciplinary involvement of nephrology. Our third patient is a 59-year-old male with dedifferentiated liposarcoma that involved the spleen, pancreas, and splenic flexure while engulfing the left kidney and ureter. Beyond the removal of the tumor, multiorgan resection was imperative to achieve microscopic margin-free resection. This extensive local spread needed broad collaboration from the medical team and other surgical subspecialties. All surgeries went well, and their outcomes were promising. All patients had an uneventful follow-up and, to date, no recurrence. Invasive retroperitoneal sarcomas of different histological types and clinical stages represent a technical challenge. Careful preoperative investigation and an experienced, dedicated multidisciplinary team of surgeons and non-surgeons from related fields, including vascular, urologic, and hepatobiliary surgeons, are usually needed for a safe and successful R0 resection despite extensive tumor involvement in light of difficulty achieving early diagnosis.

Liposarcoma Masquerading as Immunoglobulin G4-Related Disease

This case report highlights the challenge of differentiating between immunoglobulin G4 (IgG4)-related disease (IGRD) and liposarcoma, which have similar symptoms and serological markers. A 40-year-old woman presented with right upper-quadrant pain and a retroperitoneal mass. Initial biopsy indicated increased IgG4-positive cells, leading to an IGRD diagnosis. However, the mass grew, despite prednisone treatment, prompting a repeat biopsy that revealed well-differentiated liposarcoma. Liposarcoma should be considered in patients with retroperitoneal masses and elevated IgG4 levels. Surgical resection is the primary treatment, emphasizing the need for early identification and close monitoring. Confirming IGRD or ruling out other diagnoses through histopathologic analysis is vital.

Predictors and outcomes of recurrent retroperitoneal liposarcoma: new insights into its recurrence patterns

BACKGROUND

The clinical profiles of recurrent retroperitoneal liposarcoma (RLS) need to be explored. The recurrence patterns of RLS are controversial and ambiguous.

METHODS

A total of 138 patients with recurrent RLS were finally recruited in the study. The analysis of overall survival (OS) and recurrence-free survival (RFS) was performed by Kaplan‒Meier analysis. To identify independent prognostic factors, all significant variables on univariate Cox regression analysis (P ≤ 0.05) were subjected to multivariate Cox regression analysis. The corresponding nomogram model was further built to predict the survival status of patients.

RESULTS

Among patients, the 1-, 3-, and 5-year OS rates were 70.7%, 35.9% and 30.9%, respectively. The 1-, 3- and 5-year RFS rates of the 55 patients who underwent R0 resection were 76.1%, 50.8% and 34.4%, respectively. The multivariate analysis revealed that resection method, tumor size, status of pathological differentiation, pathological subtypes and recurrence pattern were independent risk factors for OS or RFS. Patients with distant recurrence (DR) pattern usually had multifocal tumors (90.5% vs. 74.7%, P < 0.05); they were prone to experience changes of pathological differentiation (69.9% vs. 33.3%, P < 0.05) and had a better prognosis than those with local recurrence (LR) pattern. R0 resection and combined organ resection favored the survival of patients with DR pattern in some cases.

CONCLUSIONS

Patients with DR pattern had better prognosis, and they may benefit more from aggressive combined resection than those with LR pattern. Classifying the recurrence patterns of RLS provides guidance for individualized clinical management of recurrent RLS.

Predictors and outcomes of recurrent retroperitoneal liposarcoma with multiple tumors

Background

Retroperitoneal liposarcoma (RLS) is a rare but severe disease. Repeated postoperative recurrence with multiple tumors is a therapeutic dilemma. The clinical outcomes and survival predictors of recurrent RLS with multiple tumors remain to be explored.

Methods

Patients with recurrent RLS were retrospectively analyzed. Univariate and multivariate analysis was performed to find independent prognostic factors that were correlated with Overall survival (OS) or progression-free survival (PFS). Factors significant in univariate analysis were further included into multivariate Cox proportional hazards regression model. The nomogram model was built to predict the survival status of patients. Variables that were significant in multivariable analysis were added to the internally validated nomogram models. The analysis of OS and PFS was performed by Kaplan-Meier analysis and log-rank test.

Results

A total of 113 recurrent RLS patients with multiple tumors were enrolled in the study. The 1-, 3-, and 5-years OS (PFS) rates were 70.7% (76.1%), 35.9% (76.1%), and 30.9% (76.1%), respectively. Univariate and multivariate analyses showed that number of surgeries, resection methods, tumor size, status of pathological differentiation, pathological subtypes, and recurrence patterns were important prognostic factors for OS or PFS (each p < 0.05). Nomogram models were established to efficiently predict the prognostic status of patients. Patients with the local recurrence (LR) pattern had a poor prognosis and would derive no survival benefit from combined organ resection and R0/R1 resection (each p < 0.05).

Conclusion

RLS patients recurrence with multiple tumors had a poor prognosis. Those patients should be followed up more frequently after surgery. The strategies of aggressive resection may not improve the survival of patients with LR pattern in the retroperitoneum. Prognostic factors in the efficient nomogram models should be considered in the individualized clinical management of recurrent RLS with multiple tumors.

Giant retroperitoneal well differentiated liposarcoma: A case report and literature review

INTRODUCTION AND IMPORTANCE

The most prevalent type of primary retroperitoneal tumors is soft tissue sarcoma (STS). Liposarcoma accounts for 40 % of retroperitoneal tumors (Mack, 1995). Retroperitoneal liposarcoma accounts for 12 % to 40 % of all liposarcomas (Vijay and Ram, 2015). They typically present with advanced disease and often carry a poor prognosis. Because of their rarity and anatomic location, these malignant tumors can cause a diagnostic dilemma and present several therapeutic challenges (Vijay and Ram, 2015).

CASE PRESENTATION

A 48-year-old male patient presented to our gastrointestinal oncology clinic with a 2-year history of abdominal discomfort, weight loss and steadily growing abdominal swelling. A soft, rubbery lobulated mass with a positive "slippage sign" was palpable over all the quadrants of the abdomen. CT scan conclusion was retroperitoneal lipoma with internal enhancing nodular components. During laparotomy, a fatty mass measuring 55*60*22 cm and weighing 14 kg was excised. Histopathologic report showed a well differentiated liposarcoma (WDLS).

CLINICAL DISCUSSION

Giant retroperitoneal liposarcoma (RPL) is exceedingly rare. Liposarcomas have diverse MRI and CT appearances due to the various subtypes. WDLS are difficult to identify from lipomas before surgery. Histopathology is the only way to provide a reliable diagnosis; therefore en block resection is the recommended approach when malignancy cannot be ruled out.

CONCLUSION

Although imaging with ultrasound, CT, and MRI can aid in the diagnosis, differentiating WDLS from lipoma pre-operatively can be difficult, and en block resection is the recommended approach when malignancy cannot be ruled out.

Whole exome sequencing of well-differentiated liposarcoma and dedifferentiated liposarcoma in older woman: a case report

Background

Common kinds of soft tissue sarcomas (STS) include well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS). In this case, we present a comprehensive clinical profile of a patient who underwent multiple recurrences during the progression from WDLPS to DDLPS.

Case presentation

A 62-year-old Asian female underwent retroperitoneal resection of a large tumor 11 years ago, the initial pathology revealed a fibrolipoma-like lesion. Over the next six years, the patient underwent three resections for recurrence of abdominal tumors. Postoperative histology shows mature adipose tissue with scattered "adipoblast"-like cells with moderate-to-severe heterogeneous spindle cells, pleomorphic cells, or tumor giant cells. Immunohistochemistry (IHC) demonstrated positive staining for MDM2 and CDK4, confirming that the abdominal tumor was WDLPS and gradually progressing to DDLPS. Post-operative targeted sequencing and IHC confirmed the POC1B::ROS1 fusion gene in DDLPS. Whole-exome sequencing (WES) revealed that WDLPS and DDLPS shared similar somatic mutations and copy number variations (CNVs), whereas DDLPS had more mutated genes and a higher and more concentrated amplification of the chromosome 12q region. Furthermore, somatic mutations in DDLPS were significantly reduced after treatment with CDK4 inhibitors, while CNVs remained elevated.

Conclusion

Due to the high likelihood of recurrence of liposarcoma, various effective treatments should be taken into consideration even if surgery is the primary treatment for recurrent liposarcoma. To effectively control the course of the disease following surgery, combination targeted therapy may be a viable alternative to chemotherapy and radiotherapy in the treatment of liposarcoma.

Comparative In Silico Analysis of Ultra-Hypofractionated Intensity-Modulated Photon Radiotherapy (IMRT) Versus Intensity-Modulated Proton Therapy (IMPT) in the Pre-Operative Treatment of Retroperitoneal Sarcoma

BACKGROUND

While pre-operative radiation did not improve abdominal recurrence-free survival for retroperitoneal sarcoma (RPS) in the randomized STRASS trial, it did reduce rates of local recurrence. However, the risk of toxicity was substantial and the time to surgery was prolonged. A combination of hypofractionation and proton therapy may reduce delays from the initiation of radiation to surgery and limit the dose to surrounding organs at risk (OARs). We conducted a dosimetric comparison of the pre-operative ultra-hypofractionated intensity-modulated photon (IMRT) and proton radiotherapy (IMPT).

METHODS

Pre-operative IMRT and IMPT plans were generated on 10 RPS patients. The prescription was 25 Gy radiobiological equivalents (GyEs) (radiobiological effective dose of 1.1) to the clinical target volume and 30 GyEs to the margin at risk, all in five fractions. Comparisons were made using student T-tests.

RESULTS

The following endpoints were significantly lower with IMPT than with IMRT: mean doses to liver, bone, and all genitourinary and gastrointestinal OARs; bowel, kidney, and bone V5-V20; stomach V15; liver V5; maximum doses to stomach, spinal canal, and body; and whole-body integral dose.

CONCLUSIONS

IMPT maintained target coverage while significantly reducing the dose to adjacent OARs and integral dose compared to IMRT. A prospective trial treating RPS with pre-operative ultra-hypofractionated IMPT at our institution is currently being pursued.

A case of retroperitoneal liposarcoma extending through the inguinal canal to the thigh and lesser trochanter

Introduction

Liposarcoma is the most common retroperitoneal soft tissue tumor. Liposarcomas are often asymptomatic and are discovered after they become huge. Surgical resection is the first-line treatment for retroperitoneal liposarcoma, but the surrounding organs are often resected with the liposarcoma.

Case presentation

A man saw a hospital with a complaint of left lower abdominal distention, and a left retroperitoneal mass was noted on imaging examination. The patient was referred to our hospital. The mass extended from the retroperitoneum through the inguinal canal to the thigh and involved the femoral nerve and psoas major muscle. A well-differentiated liposarcoma was suspected, and an open surgical resection was performed. Complete resection of a retroperitoneal liposarcoma extending to the thigh was achieved without postoperative complications.

Conclusion

Treatment strategies for huge retroperitoneal liposarcomas are important to balance antitumor efficacy and postoperative quality of life.

Survival analysis and prognostic factors of retroperitoneal liposarcoma curative surgery in a single centre. Analysis of adjacent organ invasion between imaging and definitive histopathology

INTRODUCTION

Retroperitoneal liposarcoma (RPL) is a rare primary mesenchymal tumour that develops in retroperitoneal adipose tissue. Unlike the majority of published series, this homogeneous cohort focuses on RPL. The main purpose of this study is to evaluate the overall and recurrence-free survival of RPLs who underwent excision surgery and the prognostic factors involved.

PATIENTS AND METHODS

A total of 82 patients from a single centre, who underwent curative surgery for histologically confirmed retroperitoneal liposarcoma between 2008 and 2020, were analysed in the study. Compartmental surgical excision was advised as per the guidelines. The primary endpoints were 5 years of overall survival and recurrence-free survival. Predictable tumour invasion of adjacent organs, based on a pre-operative CT scan, was also investigated to test the correlation between pre-operative imaging and pathological data.

RESULTS

Median follow-up was 61.6 months. Five year overall survival was 71.9% [95% CI: 59.8; 80.9] and 5 year recurrence-free survival was 49% [95% CI: 36.4; 60.5]. Following multivariable analysis, the factors influencing overall survival were tumour rupture and onset of severe complications (Dindo-Clavien grade ≥3). Factors influencing recurrence-free survival were neoadjuvant radiotherapy and tumour rupture. A significant correlation (p < 0.05) was found between predicted invasion based on a CT scan of the colon, spleen, adrenal gland, posterior abdominal wall and diaphragm, and pathological invasion.

CONCLUSIONS

Curative compartmental surgery remains the gold standard treatment for RPL. This study, highlights the fact that the quality of the surgical excision is a crucial factor in patient prognosis.

Malignant adipocytic tumours: A 20‑year single‑centre retrospective study

Adipocytic tumours are the most common soft tissue neoplasms. Among them, liposarcoma is the most frequent malignant neoplasm. However, to the best of our knowledge, no previously published study has assessed the evolution and oncological prognosis of the different subtypes of liposarcoma at the retroperitoneal level compared with at other locations. The present study is a retrospective observational study in which all patients were operated on between October 2000 and January 2020 with a histological diagnosis of liposarcoma. Variables, such as age, sex, location, histological type, recurrence, type of treatment and mortality, among others, were analysed. The patients were divided into two groups: Group A (retroperitoneal location) and group B (non-retroperitoneal location). A total of 52 patients with a diagnosis of liposarcoma (17 women and 35 men) and a mean age of 57.2±15.9 years were assessed. A total of 16 patients were classified into group A and 36 into group B. The OR of recurrence was 1.5 (P=0.02) for R1 vs. R0 resection in group A. The OR of recurrence in group B for R1 vs. R0 resection was 1.8 (P=0.77), whereas for R2 vs. R0 resection, the OR was 69 (P=0.011). In conclusion, 52 cases of malignant adipocytic tumours collected during 2000-2020 were analysed with the new World Health Organization classification (updated 2020). Although its recurrence potential and capacity for distant metastasis depended on each histological type, surgical treatment with unaffected margins was the main prognostic factor for survival. The present study identified differences in relation to the survival of each histological subtype and its location, finding greater survival in dedifferentiated liposarcoma, myxoid liposarcoma and pleomorphic liposarcoma located at the extraperitoneal level than in the retroperitoneal location. Resectability was not influenced by liposarcoma location.

Long-term results of huge deep-seated liposarcoma in the thigh: Two case reports

RATIONALE

Liposarcoma is an uncommon malignant tumor that develops in the fatty tissue; thus, the long-term follow-up results of extremely large liposarcomas in the submuscular layer of the thigh have rarely been reported. Here we share the course and outcome of 2 cases of a huge deep-seated liposarcoma in the thigh.

PATIENT CONCERNS

Two patients visited our clinic, each with a deep-seated mass in the thigh. First, a 44-year-old man presented to the outpatient clinic with a left thigh mass. Approximately 1 year later, an 80-year-old man presented to the outpatient clinic with a right posterior thigh mass.

DIAGNOSIS

Magnetic resonance imaging revealed an approximately 14 × 8 × 21 cm well-differentiated liposarcoma between the sartorius and iliopsoas muscle and an approximately 14 × 12 × 31.5 cm lipomatous mass in the posterior compartment of the right thigh involving the right adductor muscles. After complete marginal resection, an excisional biopsy was performed to confirm the diagnosis.

INTERVENTIONS

Both patients underwent complete marginal resection without chemotherapy or radiotherapy.

OUTCOMES

A biopsy showed a 20 × 17 × 7 cm well-differentiated, well-encapsulated liposarcoma in the 44-year-old man and a 30 × 17 × 10 cm well-differentiated liposarcoma in the 80-year-old man. These patients have achieved approximately 61 and 44 months of recurrence-free survival to date, respectively.

LESSONS

Here we described the long-term outcomes of 2 patients with a huge deep-seated liposarcoma in the lower extremity. Complete marginal excision of well-differentiated liposarcoma can achieve excellent recurrence-free survival.

Recurrent metastatic retroperitoneal dedifferentiated liposarcoma: a case report and literature review

BACKGROUND

Retroperitoneal liposarcoma (RPLPS), a rare tumor, is often treated using surgical procedures as the first choice for treatment. However, there is no consensus on the scope of surgical resection. In addition, the treatment outcomes of conventional radiotherapy and chemotherapy have not been satisfactory, particularly for specific types of LPS, such as dedifferentiated LPS. In this case study, we present a brief review of other cases of RPLPS, highlighting the selection of surgical scope for RPLPS and related adjuvant treatment for advanced RPLPS.

CASE PRESENTATION

A case study is reported regarding an extremely rare recurrent and metastatic retroperitoneal dedifferentiated LPS. The primary RPLPS tumor, with a diameter of 20 cm and a weight of 2.5 kg, occupied the whole left abdomen and adhered to the left kidney. A surgical tumor resection combined with a left nephrectomy is performed. During the 6th -month postoperative follow-up examination, we observed the local recurrence of the tumor in the operation area, in addition to multiple metastatic tumors in both lungs. Further, the prescribed 3-month targeted treatment with anlotinib significantly reduced the size of the metastatic pulmonary tumors. However, the recurrent retroperitoneal tumors showed no significant change in size. Eventually, we observed no substantial evidence of tumor progression, with the patient's condition under control.

CONCLUSION

The case demonstrated that the postoperative recurrence of widespread RPLPS required R0 resection to cure the disease, considering targeted therapy for advanced RPLPS control.

An Unexpected Cause of Syncope

Syncope is a common chief complaint among patients presenting to the emergency department, the etiology of which can often be discerned with a thorough history and physical examination. Inversely, liposarcomas are rare tumors that frequently pose a diagnostic challenge as the clinical presentation is highly nonspecific and varies greatly depending on the anatomic location and size of the tumor. Here we present a case of retroperitoneal liposarcomas (RLS) presenting to the emergency department (ED) with a sole complaint of syncope, resulting in a diagnostic dilemma. This clinical scenario highlights the significance of thorough physical examination regardless of the presenting chief complaint, as unexpected physical examination findings prompted an extended work-up and thus facilitated the diagnosis, providing the opportunity for early intervention and resection of the tumor.

Pleomorphic Liposarcoma Revisited

Pleomorphic liposarcoma (PLPS) is the rarest and more aggressive subtype of liposarcomas, accounting for 10% of all liposarcomas. The diagnosis should be considered after the detection of multivacuolated pleomorphic lipoblasts in biopsy specimens. Wide-margin resection is the treatment of choice. Complementary treatment options, such as radiation therapy and chemotherapy, are debatable in terms of their contribution to curing patients with PLPS. This article reviews the clinical, histopathological, and molecular characteristics of PLPS and discusses the latest trends in the management, therapeutic strategies, and novel investigations of the subject. [Orthopedics. 2023;46(2):e72-e80.].

Case report and literature review: Conversion surgery for initially unresectable huge retroperitoneal liposarcoma after preoperative radiotherapy

Background

Retroperitoneal liposarcoma (RPLS) is a rare malignancy that is notorious for recurrence. Surgical resection with clean margin is the current treatment of choice. However, owing to the large retroperitoneal space, RPLSs often grow to significant sizes before being diagnosed. Neoadjuvant and adjuvant therapies have potentials to improve long term treatment outcome.

Case presentation

A 55-year-old Han Chinese male presented to the general surgery department with a one-year history of abdominal fullness and a one-week history of palpable right inguinal mass. At first, he was diagnosed with incarcerated inguinal hernia. However, abdominal computer tomography (CT) and biopsy confirmed his final diagnosis to be retroperitoneal well-differentiated liposarcoma, cT2bN0M0, stage IIb. The tumor, which measured 44.5cm in maximum diameter, was too large for primary surgical resection. Neoadjuvant radiotherapy with 70 Gy in 35 fractions was delivered to the tumor, which shrunk the target volume from 6300 cc to 4800 cc, as observed in the middle of the radiotherapy course. The right testicular mass also received 70Gy/35Fx. Conversion surgery was performed after radiotherapy. Unfortunately, due to residual tumor, adjuvant chemotherapy consisting of AIM (ifosfamide, Mesna, and doxorubicin) and MAID (Mesna, doxorubincin, ifosfamide, and dacarbazine) regimens were administered sequentially. Afterward, debulking surgery was conducted, plus another 18 cycles of ifosfamide monotherapy when residual tumor was still seen on CT. Since the completion of ifosfamide chemotherapy, the patient has been cancer free with no evidence of tumor recurrence for more than 26 months.

Conclusion

Despite conflicting evidence in the literature, our case supports the use of high dose neoadjuvant radiotherapy and adjuvant chemotherapy in treating large, unresectable RPLSs. It also highlights the importance of using individualized, multidisciplinary approach in achieving cure for large, unresectable rare tumors.

Survival of a patient with multiple-recurrent giant retroperitoneal dedifferentiated liposarcoma for 15 years: A case report

Background

Retroperitoneal liposarcoma (RPLS) is a variety of soft tissue sarcoma that originates from mesenchymal cells. A tumor measuring greater than 30 cm is called a “giant liposarcoma.” A part of the neoplasm tends to grow in size, recur locally, or metastasize distantly. In those with such a condition, long-term survival is uncommon. Therefore, it is necessary to present a uniform and optimized program to improve the prognosis.

Methods

By successfully treating a multiple-recurrent giant retroperitoneal dedifferentiated liposarcoma (RP DDLPS) in July 2010, we hope to devise more comprehensive strategies to improve diagnosis, therapy, and outcome.

Results

In July 2010, we thoroughly resected a giant multifocal RPLS with a concomitant part of the gastric wall. The histopathological examination revealed a high-grade (grade III) dedifferentiated liposarcoma. The patient was discharged uneventfully on the 15th postoperative day. She relapsed after 16 months and needed another complete excision. After 9 months, she died after the fourth recidive. The patient had experienced four recurrences and underwent operations with 15 years of follow-up.

Conclusions

The above demonstrates that we were able to successfully treat the multirecurrent giant RPLS, despite the patient’s poor medical condition, with meticulous management. Moreover, this indicates that long-term survival could be achieved for high-grade RP DDLPS.

Retroperitoneal lipoma and bilateral renal cell carcinoma in a rare co-existence

Introduction

Giant retroperitoneal lipomas are rarely observed clinically, and a retroperitoneal lipoma accompanied by renal cell carcinoma is even more unusual. We present a case of a large retroperitoneal lipoma with bilateral renal cell carcinoma that was definitively diagnosed after resection.

Case presentation

A huge retroperitoneal mass was incidentally discovered in a 58-year-old male with end stage renal disease being evaluated for a kidney transplant. Imaging studies revealed a mixed solid and fat-containing mass displacing the left kidney. Repeat imaging discovered concurrent unilateral renal cell carcinoma and interval enlargement of the mass. Histopathology showed benign adipose tissue, bland spindle cells, and mixed inflammatory infiltrate that was negative for MDM2 amplification. Resection of the mass and bilateral nephrectomy was performed. Final histopathological examination was consistent with bilateral renal cell carcinoma and a large benign retroperitoneal lipoma.

Discussion

The presented case provides a prime example of the diagnostic challenges encountered with retroperitoneal tumors, The final diagnosis of lipoma in this case was only made after review of the resected specimen in its entirety. Retroperitoneal lipomas can present differently based on tumor size and involvement of adjacent organs. The concomitant occurrence of a renal cell carcinoma and retroperitoneal lipoma is extremely rare, and this is the first report published in the literature.

Conclusion

We document a rare case of retroperitoneal lipoma with concurrent bilateral renal cell carcinoma and illustrate frequently encountered challenges during the evaluation of retroperitoneal masses.

•

This retroperitoneal lipoma with bilateral renal cell carcinoma is the first case to be reported in the medical literature.

•

This case provides a prime example of the diagnostic challenges encountered with retroperitoneal tumors.

•

We illustrated frequently encountered challenges during the evaluation of retroperitoneal masses.

Evaluation of Efficacy of Adjuvant Radiotherapy in Well-Differentiated Liposarcoma Patients with Positive Surgical Margins: A Population-based Study

Background

The use of adjuvant radiotherapy (RT) for well-differentiated liposarcoma (WD-LPS) patients with positive surgical margins is unclear. We aim to compare the overall survival (OS) and cancer-specific survival (CSS) of well-differentiated liposarcoma patients with positive surgical margins in an RT group and non-RT group.

Methods

WD-LPS patients with positive margins from 2000 to 2018 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database and divided into two groups: RT group and non-RT group. Kaplan–Meier survival analysis with the log-rank test was performed to evaluate the difference of overall survival (OS) and cancer-specific survival (CSS) between groups. Univariate and multivariate Cox proportional hazard analyses were performed to identify important prognostic factors of OS and CSS. Analyses were adjusted using propensity-score matching.

Results

We identified 2549 patients: 377 (14.79%) with RT and 2172 (85.21%) without RT. The median age was 61 years, and the median follow-up time was 68 months. The log-rank test revealed that there was no significant difference of CSS between RT and non-RT groups (P = 0.81). The 5-year and 10-year CSS were comparable (P = 0.418 and P = 0.987). Additionally, the use of RT was neither an independent prognostic factor for OS nor CSS. Age, sex, tumor site, the use of chemotherapy were independent prognostic factors for OS after propensity score matching, while race and the tumor site were independent prognostic factors for CSS.

Conclusion

Adjuvant RT had no significant improvement on OS and CSS of WD-LPS patients with positive surgical margins.

Giant retroperitoneal liposarcoma treated with radical conservative surgery: A case report and review of literature

BACKGROUND

Retroperitoneal liposarcoma (RLPS) is a rare malignant tumor of the connective tissue and usually grows to a large size, undetected. Diagnosis is currently based on collective findings from clinical examinations and computed tomography (CT) and magnetic resonance imaging, the latter of which show a fat density mass and possible surrounding organ involvement. Surgical resection is the main therapeutic strategy. The efficacy and safety of further therapeutic choices, such as chemotherapy and radiotherapy, are still controversial.

CASE SUMMARY

A 61-year-old man presented with complaint of a large left inguinal mass that had appeared suddenly, after a slight exertion. Ultrasonography revealed an omental inguinal hernia. During further clinical examination, an enormous palpable abdominal mass, continuing from the left inguinal location, was observed. CT revealed a giant RLPS, with remarkable mass effect and wide visceral dislocation. After multidisciplinary consultation, surgical intervention was performed. Subsequent neoadjuvant chemotherapy and radiotherapy were precluded by the mass’ large size and retroperitoneal localization, features typically associated with non-response to these types of treatment. Instead, the patient underwent conservative treatment via radical surgical excision. After 1 year, his clinical condition remained good, with no radiological signs of recurrence.

CONCLUSION

Conservative treatment via surgery resulted in a successful outcome for a large RLPS.

Pancreatic liposarcoma: a case report

An 81-year-old woman who had undergone total thyroidectomy for papillary thyroid cancer 12 years earlier was found to have a tumor in the tail of the pancreas. Four years earlier, skin, lung, and mediastinal lymph node metastases had appeared. Computed tomography (CT) showed a mass 26 mm in diameter in the tail of the pancreas. Thereafter, the pancreatic tumor increased in size, while the lung metastases remained stable. Unenhanced CT at the time of first detection showed that the tumor was heterogeneous, with low-attenuation areas indicating fat components. As the tumor grew, the fat components became unclear. Laparoscopic distal pancreatectomy and splenectomy were performed. The tumor was diagnosed as dedifferentiated liposarcoma with a well-differentiated liposarcoma component at the tumor margin. The pancreas is an extremely rare site of primary liposarcoma. In the present case, a pancreatic liposarcoma appeared during follow-up of thyroid cancer, and the changes over time were able to be observed with CT.

Giant retroperitoneal well-differentiated liposarcoma presenting in emergency with intestinal occlusion: Case report and review of the literature

INTRODUCTION AND IMPORTANCE

Liposarcoma (LPS) represents the most common type of retroperitoneal sarcoma (RPS) and can be classified into four subtypes. Preoperative diagnosis of retroperitoneal liposarcoma (RLPS) is a challenge because of its late and nonspecific clinical presentation. Imaging may be helpful for determining the correct diagnosis. Surgery represents a potentially curative treatment of RLPS.

CASE PRESENTATION

A 55-year-old Caucasian female presented to the Emergency Department with a two-day history of abdominal pain, abdominal distension, inability to pass gas or stool, nausea, vomiting and lipothymia. Abdominal examination revealed abdominal distention, abdominal pain without obvious muscle guarding and a giant non-tender mass. Laboratory tests reported neutrophilic leukocytosis and anemia. Abdominal contrast-enhanced computed tomography (CECT) showed a heterogeneous and hypodense giant retroperitoneal mass compressing and displacing the surrounding organs and vessels. The patient underwent excision of a giant retroperitoneal mass. The postoperative course of the patient was uneventful.

CLINICAL DISCUSSION

RLPS is a malignant neoplasm that can slowly grow to enormous size with possible involvement of adjacent organs and vessels; it may recur locally and has a minimal capacity to metastasize. Preoperative diagnosis and staging of RLPS are important to establish appropriate management and prognosis. Surgery represents the gold standard for non-metastatic RLPS treatment.

CONCLUSION

RLPS is a rare malignant neoplasm generally difficult to detect early due to its late and nonspecific clinical presentation. CECT represents the most commonly used modality for diagnosis, staging and preoperative evaluation. Surgery represents the appropriate treatment of non-metastatic RLPS.

Case Report: Retroperitoneal Sarcoma in Six Operations: Our Experience in Operative Management of Blood Vessels

Here we introduce a case of retroperitoneal liposarcoma, which is characterized by repeated recurrences after surgery, and has undergone a total of 6 operations. The diameter of the tumor was about 26 cm at the time of the patient's diagnosis. The imaging examination revealed that the surrounding organs and blood vessels were invaded, which brought great challenges to radical resection. The postoperative pathology of the patient’s first operation was dedifferentiated liposarcoma, and some areas showed myxofibrosarcoma differentiation. With the recurrence of sarcoma, myxofibrosarcoma dedifferentiated into rhabdomyosarcoma, and malignant fibrous histiocytoma appeared in some areas. How to treat this type of patient after recurrence? How to deal with blood vessels wrapped by sarcoma during surgery? The medical community has not yet reached the same conclusion. We describe the process of treating the patient and the experience of dealing with blood vessels during surgery.

Retroperitoneal Liposarcoma: An Unusual Presentation of a Rare Cancer

Retroperitoneal liposarcomas (RLPS) are rare tumors that have variable clinical behavior and complex treatment strategies based on presentation, histopathology, and genomics. Early identification is critical, and complete surgical resection remains the primary treatment, although chemotherapy and radiation are used on individual bases. Presenting symptoms are often nonspecific; therefore, a high degree of suspicion is essential for early diagnosis. In this report, the management of a 37-year-old otherwise healthy male with a large RLPS causing right groin/testicular pain is presented. After three evaluations in the emergency department, the patient was diagnosed and received two cycles of doxorubicin/ifosfamide/mesna (AIM) neoadjuvant chemotherapy. His physical exam on presentation for second opinion demonstrated a large palpable abdominal mass and fullness around the right spermatic cord. There was no appreciable change in tumor size or distant metastases on repeat scanning. Given some obstructive symptoms, a multidisciplinary team advised neoadjuvant radiation followed by radical resection of RLPS. Final pathology demonstrated a 31-cm grade II well-differentiated (WD) liposarcoma with low-grade dedifferentiation. Scattered foci of microscopic positive WD margins were noted, and the remainder of margins were negative. Genomic evaluation showed amplification of CDK4, MDM2, and FRS2. A concise literature review of common presentations, histopathology, genomics, and treatment information is discussed herein. Thorough physical exams, attention to subtle findings, appropriate medical imaging studies, and a high index of suspicion when evaluating vague symptomatology can lead to earlier diagnosis and treatment of RLPS, and ultimately better patient outcomes.

Giant retroperitoneal lipoma presenting with abdominal distention: A case report and review of the literature

BACKGROUND

Retroperitoneal lipomas are extremely rare tumors and tend to be large in size (> 10 cm) when diagnosed, causing various clinical manifestations. Preoperative diagnosis of retroperitoneal lipomas is difficult. There is a lack of relevant information about the management and prognosis of these benign tumors due to limited reports.

CASE SUMMARY

A 53-year-old woman who complained about progressive abdominal distention and aggravating satiety was referred to the gynecological outpatient department of Peking Union Medical College Hospital. Computerized tomography (CT) revealed an immense mass with fat density, measuring 28.6 cm× 16.6 cm in size. Adjacent organs, including the intestinal tract and uterus, were squeezed to the right side of the abdomen. An exploratory laparotomy was performed with suspicion of liposarcoma. Intraoperatively, a giant yellowish lobulated mass was found occupying the retroperitoneum and it was removed by tumor debulking. Postoperative histopathological results confirmed the diagnosis of retroperitoneal lipoma.

CONCLUSION

Retroperitoneal lipoma is a very rare condition and is difficult to differentiate from well-differentiated liposarcoma. Radiographic investigations, especially CT and magnetic resonance imaging, are important for preoperative diagnosis. Surgical resection is the fundamental treatment, which is difficult due to its size and relation to neighboring structures.

Hyper-accuracy three-dimensional reconstruction as a tool for better planning of retroperitoneal liposarcoma resection: A case report

BACKGROUND

Well-differentiated liposarcoma is the second most common pathologic type of retroperitoneal sarcoma. It is characterized by a huge mass, but multiple organ invasions are common. Surgery is the only treatment option for potential cure. Hyper-accuracy three-dimensional (3D) reconstruction is widely used in robotic partly nephrectomy owing to its ability to visualize overlapping anatomy.

CASE SUMMARY

A 54-year-old man was admitted for progressive abdominal distension over the preceding 2 mo. Computed tomography revealed a 32 cm × 21 cm × 12 cm lipomatous mass. Hyper-accuracy 3D reconstruction was performed because of the complex relationship between the mass and nearby tissue. The patient underwent surgical resection, and the tumor did not recur for over 16 mo.

CONCLUSION

Hyper-accuracy 3D reconstruction is useful for operative planning owing to its intuitiveness and precise determination of anatomical structures in both tumors and nearby tissues.

Case report: Two cases of primary paratesticular liposarcoma

Paratesticular liposarcoma is a sporadic urological tumor. We report the clinical presentation, treatment course, and prognosis of 2 cases of primary paratesticular liposarcoma with different pathological types, with the aim of further understanding the diagnosis and treatment of this rare disease. Case 1 was a 53-years-old male patient who presented with left scrotal enlargement with swelling 3 years ago and was considered to have a testicular malignancy on preoperative CT scan and enhanced MRI. The patient underwent resection of the left scrotal mass and left orchiectomy under general anaesthesia. Histopathological study confirmed the diagnosis of dedifferentiated liposarcoma. At the 4-months follow-up, no local recurrence or distant metastasis was observed. Case 2 is a 42-years-old male patient with a left scrotal mass which was discovered six months ago. Preoperatively, he underwent CT plain and enhanced MRI examinations suggesting an intra-scrotal occupancy. The patient underwent scrotoscopic excision of the left scrotal mass under general anesthesia. Histopathological studies confirmed the diagnosis of highly differentiated liposarcoma. At the 10-months follow-up, no local recurrence or distant metastasis was observed. Preoperative differential diagnosis of paratesticular liposarcoma should be noted with testicular tumor and extra-abdominal hernia. Extensive local excision and, if necessary, concomitant radical testicular resection is the treatment of choice. If the tumor in the scrotum spreads to the inguinal region, surgical removal with the aid of a scrotoscope may be attempted. This procedure avoids the formation of a large incision in the inguinal region compared to traditional open surgery. Patients commonly experience local recurrence and less distant metastases after surgery, so long-term follow-up is recommended.

A Successful En Bloc Excision of a Giant Retroperitoneal Liposarcoma With Distal Splenopancreatectomy

Retroperitoneal sarcomas are considered a rare type of malignant tumors, accounting for fewer than one-fifth of all cases. Among all malignancies, the incidence of soft tissue sarcomas is approximately 1%. It constitutes 38% of soft tissue sarcomas in liposarcomas. Putting it that way may better indicate that liposarcomas are a rare tumor. They are frequently asymptomatic until they become large enough to compress the adjacent organs. As a result, it must be validated using appropriate imaging modalities, for example, computed tomography (CT) abdomen or magnetic resonance imaging (MRI) abdomen with contrast. The preferred treatment is complete surgical resection.

The patient presented with vague symptoms. She had a CT abdomen with contrast, as well as an MRI abdomen. Both images revealed the presence of a giant sarcoma displacing the pancreas and left kidney posteriorly and the transverse colon inferomedially. The patient underwent en bloc resection of the mass with distal splenopancreatectomy. The patient tolerated the procedure well and was discharged on day 6 postoperatively in a stable state.

Giant liposarcoma is a rare and aggressive form of sarcoma. Because of the unique presentation, it is difficult to diagnose clinically. CT scans with MRIs are viable imaging modalities for determining tumor extent and ruling out any vascular invasion. Complete surgical resection of liposarcoma is a treatment of choice. En bloc resection of retroperitoneal sarcoma with distal splenopancreatectomy can be performed successfully and safely.

A Rare Case of Dedifferentiated Retroperitoneal Liposarcoma Presenting As Cardiac-Sounding Chest Pain

Retroperitoneal liposarcomas (RPL) are rare mesenchymal tumours with an annual incidence of 2.7 cases per million. Well-differentiated liposarcomas (WDLs) and dedifferentiated liposarcomas (DDLs) are the most common subtype. WDLs are widely known to be low-grade tumours that are less likely to metastasise and easily resected. In contrast, DDLs are high-grade aggressive metastatic tumours with mortality rates between 50% and 70%.

We present an unusual case of a 47-year-old male with a background of hypertension presenting with cardiac-sounding chest pain. Initially managed as an acute coronary syndrome (ACS), he eventually underwent a CT scan which revealed a 20x18x17cm retroperitoneal complex mass with possible infiltrates to the posterior wall of the greater curvature of the stomach. Ultrasound-guided biopsy and subsequent histopathology analysis revealed DDL consistent with MDM2 amplification.

This case highlights how RPL can present with diagnostic difficulties. Multidisciplinary input from haematology, surgery and specialist teams is vital to optimise patient management.

Development and Validation of a Nomogram for Predicting Recurrence-Free Survival of Surgical Resected Retroperitoneal Liposarcoma

Background and Objectives

Surgical treatment is still the mainstay of curative therapy for retroperitoneal liposarcoma (RLPS), but often recurs after surgical resection. We aimed to establish a nomogram for postoperative recurrence of RLPS based on the Asian population.

Methods

Patients after surgical resection at the South Hospital of Zhongshan Hospital/Shanghai Public Health Clinical Center between August 2011 and December 2020 were included. The enrolled patients are randomly divided into training set and test set according to the ratio of 7:3. Prognostic factors were chosen based on Akaike Information Criterion, and the nomogram was built based on Cox regression and then internally validated through calibration plots and concordance index (C-index).

Results

A total of 447 patients were included. Gender, age, presentation status, organ invasion and FNCLCC grade were used to build nomogram. The calibration plots showed that RFS predicted probabilities are identical to the actual RFS rates. The C-index of the nomogram was 0.703 (95% CI 0.623–0.783) in the training set and 0.695 (95% CI 0.565–0.825) in test set.

Conclusion

The nomogram we established can accurately predict postoperative recurrence of RLPS patients for Asian population.

Recurrent giant retroperitoneal liposarcoma: Review of literature and a rare case report

Introduction and importance

Retroperitoneal liposarcomas (RPLS) are usually grow large with frequent recurrences. Complete surgical excision remains the gold standard treatment for primary and even recurrent tumours. Their prognosis depends on their histological type and grade. We report a recurrent giant de-differentiated RPLS weighing 18.55 kg which was completely excised. To the best of our knowledge, this is one of the largest liposarcoma reported in the literature.

Case presentation

A 40 year old female presented with a gradually progressing large abdominal lump for 1year. She had had a similar large lump twice in the past and undergone excision of the tumour elsewhere. Firm non-tender mass felt all over abdomen with edema noted over abdominal wall and bilateral lower limbs. PET CT showed large heterogeneously enhancing mass occupying almost the entire abdominopelvic cavity. 50 × 40 × 40cm tumour was completely excised and biopsy showed grade 2 dedifferentiated liposarcoma (DDLS). She is under close follow up with no recurrence at 12months.

Clinical discussion

DDLS have lower risk of distant metastases but have a high risk of local recurrence. The most important favourable prognostic factor in these tumours is complete resection with negative margins. Because of the ineffectiveness of current chemotherapy and the requirement of intolerably high radiation doses, surgical excision remains the most effective treatment even for the localized recurrences of RPLS.

Conclusion

The dedifferentiated subtype should be suspected in locally aggressive RPLS. Close follow up with early detection of recurrences and prompt excision with negative margins lowers the risk of recurrences and improves survival.

Retroperitoneal liposarcoma mimicking pheochromocytoma

Retroperitoneal liposarcomas are rare mesenchymal tumors which carry a poor prognosis because of their late presentation. When symptoms do occur, they are usually nonspecific and related to mass effect or invasion of local structures. Rarely, retroperitoneal liposarcomas can clinically and biochemically mimic phaeochromocytomas. We discuss one such case of a 56-year-old Afro-Trinidadian female who presented to her primary care physician with a 3-month history of weakness, intermittent sweating, difficulty sleeping and elevated blood pressure. After a 2 week trial of an oral antihypertensive regime her blood pressure was still elevated and she complained of new right sided abdominal pain. A subsequent Computed Tomography scan of her abdomen revealed an enhancing, heterogeneous right suprarenal mass suspicious for pheochromocytoma. Urinary catecholamines were also elevated and an MRI of her abdomen supported the diagnosis of pheochromocytoma although intralesionsal fat was noted, an uncommon feature of pheochromocytomas. She was booked for laparoscopic adrenalectomy. Histological analysis of the resected specimen confirmed a dedifferentiated retroperitoneal liposarcoma. While the imaging features of phaeochromocytomas and retroperitoneal liposarcomas can be similar, the presence of intralesional fat on CT and MRI should favour the diagnosis of a retroperitoneal liposarcoma, albeit the clinical and biochemical picture.

Diagnosis and Prognosis of Retroperitoneal Liposarcoma: A Single Asian Center Cohort of 57 Cases

Background

Liposarcoma is a soft tissue malignancy, commonly observed in the extremities. However, retroperitoneal liposarcoma is seldom reported and its diagnosis is frequently neglected. This study aims to present the clinical characteristics, diagnosis, and prognosis of five liposarcoma subtypes and report our experience of patient treatment.

Methods

We conducted a single-center noninterventional retrospective study of 57 retroperitoneal liposarcoma patients admitted to Peking Union Medical College Hospital (PUMCH, Beijing, China) between July 2011 and December 2019. We collected and analyzed their demographic, clinical, imaging, histological, therapeutic, and prognostic data over a mean 4.5-year follow-up period.

Results

Twenty-five (44%) patients were asymptomatic prior to diagnosis, with abdominal distension as the chief complaint in 18 (32%) patients and abdominal pain observed in 16 (28%) patients. Masses were evaluated by computed tomography (n = 48, 84%) or ultrasound (n = 25, 44%). Laparotomy (n = 52, 91%) was the dominant therapeutic modality rather than laparoscopy (n = 5, 9%). All patients were treated with R0 resection except two patients who underwent R2 resection. We conducted regular follow-ups every six months after surgery for a mean duration of 4.5 years. Recurrence was experienced by 14 (25%) patients and a further 9 (16%) died during follow-up.

Conclusions

Abdominal distension and pain are chief complaints with liposarcoma. As the extremities are the main liposarcomas locations, the diagnosis of retroperitoneal liposarcoma is usually neglected. Since half of the patients are asymptomatic, timely diagnosis and treatment are highly dependent on regular ultrasound and computed tomography imaging. R0 resection is the key to retroperitoneal liposarcoma treatment. In comparison, patients who underwent R2 resection, which is considered a palliative treatment, had bad prognoses. Large, symptomatic dedifferentiated, and pleomorphic liposarcomas are more likely to have poor prognoses, while the prognosis for well-differentiated or myxoid liposarcoma is relatively good.

Pleomorphic retroperitoneal liposarcoma with kidney infiltration mimicking renal trauma

Pleomorphic retroperitoneal liposarcoma are uncommon malignant tumor which hard to treat condition for its local aggressiveness and clinical specificity. A 84 years-old male patient complained with an abdominal mass and left flank pain without hematuria. The patient also complained of shortness of breath due to left pleural effusion. Contrast CT Scan revealed left renal hematoma with suggestive of renal trauma. Left flank exploration and tumor excision was performed to the patient. Histopathological examination showed pleomorphic retroperitoneal liposarcoma. In seventh day post-operative, the condition was fully recovered. This is an unusual presentation retroperitoneal mass. Pleomorphic retroperitoneal liposarcoma can provide atypical imaging.

Multiple well-differentiated retroperitoneal liposarcomas with different patterns of appearance on computed tomography: A case report

BACKGROUND

Primary retroperitoneal liposarcoma (PRPLS) is a rare soft tissue tumor with nonspecific clinical symptoms; it has different computed tomography (CT) image features according to pathological types. Some patients with a single tumor have been previously reported in the literature. We present an exceptional case of a PRPLS patient with multiple large tumors exhibiting different patterns of appearance on CT and confirmed as atypical lipomatous tumor/well-differentiated liposarcoma by postoperative pathology.

CASE SUMMARY

A 64-year-old man presented with abdominal distension for 1 year. The patient was diagnosed with PRPLS based on physical examination, laparotomy, ultrasonography, CT scan, and surgery. Both of the tumors were completely resected through surgery and confirmed as atypical lipomatous tumor/well-differentiated liposarcoma by postoperative pathology. The postoperative course was uneventful without recurrence or metastasis, as demonstrated by abdominal-pelvic CT during an 18 mo follow-up.

CONCLUSION

Multiple large Well-differentiated liposarcomas with different patterns of appearance on CT image can occur simultaneously in the same patient, to which more attention should be paid to make an effective differential diagnosis.

Retroperitoneal Liposarcoma Presenting With Malignant Gastric Outlet Obstruction and Acute Pancreatitis: A Case Report

Dedifferentiated liposarcomas (DDLPS) are rare, high-grade malignancies that usually originate in the retroperitoneum. Frequently, they present as asymptomatic masses, abdominal distention, abdominal pain, and weight loss. They tend to grow significantly and are usually large in size at the time of diagnosis. Surgical resection is the mainstay of treatment; however, local recurrence is common. When unresectable, they can invade local structures and produce a significant mass effect on the adjacent organs. Here we present the first case of malignant gastric outlet obstruction (MGOO) and acute pancreatitis from a retroperitoneal DDLPS.

Pancreaticoduodenectomy for Retroperitoneal Sarcomas: A Mono-Institutional Experience in China

Background

En bloc resection of retroperitoneal sarcoma (RPS) with adjacent organs such as pancreatic head and duodenum is challenging for surgeons. This mono-institutional study aims to evaluate the feasibility, safety, and outcome of performing pancreaticoduodenectomy (PD) during RPS resection.

Methods

The clinical data of RPS patients who underwent PD at the Sarcoma Center of Peking University Cancer Hospital from January 2011 to December 2019 was collected and analyzed.

Results

Twenty-seven patients out of a total of 264 surgically treated RPS underwent PD. The main pathological subtype was liposarcoma. All patients received concomitant resection of a median of three additional organs (range: 1–5), including 11 patients (40.7%) who underwent inferior vena cava resection and one patient who underwent segmental superior mesenteric-portal vein resection. Microscopic tumor infiltration to the duodenum or pancreas was observed in 81.5% of patients. Major complications occurred in 40.7% of patients; the reoperation rate was 22.2%. One patient (3.7%) died from liver abscess postoperatively. During a median follow-up of 18.9 months, 15 patients (55.6%) developed locally recurrent disease; two patients (7.4%) also had pulmonary metastases additionally. Twelve patients (44.4%) died from local relapse eventually.

Conclusion

PD during RPS resection is feasible, and it may be necessary to achieve complete resection. However, considering the complexity and risk, it should be performed by an experienced surgical team. The long-term survival benefit of this procedure should be verified by further large-scale multi-institutional studies.

A novel nomogram for predicting local recurrence-free survival after surgical resection for retroperitoneal liposarcoma from a Chinese tertiary cancer center

BACKGROUND

Local recurrence is the most difficult postoperative challenge and the leading cause of death in patients with retroperitoneal liposarcoma (RLPS). We aimed to establish a postoperative nomogram exclusively focused on RLPS for predicting local recurrence-free survival (LRFS).

METHODS

A cohort of 124 patients after surgical resection with curative intent in the Peking University Cancer Hospital Sarcoma Center were included in the study. Demographic, clinicopathologic, and treatment variables were analyzed using the Cox regression model. Significant clinically relevant variables in multivariable analysis were incorporated into the RLPS-specific nomogram. The discriminative ability and predictive accuracy of the nomogram were assessed by calculating the concordance index and drawing a calibration plot.

RESULTS

At a median follow-up of 26.5 (interquartile range 10.9-39.4) months, 71 patients had recurrent disease. The 3-year and 5-year LRFS rates were 35.6% (95% confidence interval, 27.0-46.9%) and 28.2% (95% CI 15.8-38.6%), respectively. Multivariate analysis identified the French Federation of Cancer Centers Sarcoma Group (FNCLCC) grade and completeness of resection as independent predictors of LRFS. Variables included in our nomogram were: presentation status, multifocality, completeness of resection, histologic subtypes, and FNCLCC grade. The concordance index of our nomogram was 0.732 (95% CI 0.667-0.797) and the calibration plot was excellent.

CONCLUSIONS

Our novel nomogram for patients with resected RLPS could improve recurrence risk stratification to explore molecular analysis associated with recurrence.

Giant retroperitoneal liposarcoma with a maximum diameter of 37 cm: a case report and review of literature

Retroperitoneal liposarcoma is a rare malignancy derived from adipocytes. They can grow to large sizes before inducing clinical symptoms. Giant retroperitoneal liposarcoma with a diameter over 30 centimeters is extremely rare. So far, only 13 cases of giant retroperitoneal liposarcoma with a diameter greater than 30 cm have been reported. There is very little experience in the treatment of these bulky tumors. Herein, we report a 65-year-old male patient diagnosed with giant retroperitoneal liposarcoma. The patient underwent successful complete surgical resection. The tumor was found to occupy almost the entire abdominal cavity, measuring 37.0 cm × 32.0 cm × 26.5 cm in size and 21.0 kg in weight. Histopathological analysis indicated a grade I, well-differentiated liposarcoma. The patient was discharged uneventfully, and no sign of recurrence was observed at 12-month follow-up. Moreover, we reviewed 13 literatures in English published on PubMed database regarding retroperitoneal liposarcoma greater than 30 cm in diameter. The analysis suggests that size alone should not be considered as a contraindication to surgical resection. Combined resection of adjacent organs is necessary if local invasion is confirmed. The role of adjuvant radio or chemotherapy remains controversial. Thorough evaluation on the extent of resection should be made to minimize post-surgery decline in quality of life.

Identification of TYMS as a promoting factor of retroperitoneal liposarcoma progression: Bioinformatics analysis and biological evidence

Retroperitoneal liposarcoma (RLPS) is one of the most common types of retroperitoneal sarcomas, and has a high recurrence rate. There is an urgent need to further explore its pathogenesis and develop more effective treatment strategies. The aim of the present study was to identify potential driver genes of RLPS through bioinformatics analysis and molecular biology to elucidate potential targets that are suitable for further analysis for the treatment of RLPS. Differentially expressed genes (DEGs) between liposarcoma and normal fatty (NF) tissues were identified based on microarray data through bioinformatics analysis, and thymidylate synthase (TYMS) was selected from the DEGs, based on high content screening (HCS). TYMS expression was evaluated in RLPS tumor tissues and cell lines. A total of 21 RLPS tissues and 10 NF frozen tissues were used for reverse transcription-quantitative PCR, and 47 RLPS formalin-fixed specimens were used for immunohistochemical analysis. The effect of TYMS downregulation on cell proliferation, apoptosis, cell cycle progression, and cell migration and invasion were evaluated using lentivirus-mediated short hairpin RNA. The underlying mechanisms of TYMS in RLPS were examined by protein microarray and verified by western blotting. A total of 855 DEGs were identified. TYMS knockdown had the most notable effect on the proliferative capacity of RLPS cells according to the HCS results. TYMS mRNA expression levels were higher in RLPS tissues compared with NF tissues (P<0.001). TYMS expression was higher in high-grade RLPS tissues compared with low-grade RLPS tissues (P=0.003). The patients with positive TYMS expression had a worse overall survival (OS) and disease-free survival (DFS) compared with the patients with negative TYMS expression (OS, P=0.024; DFS, P=0.030). The knockdown of TYMS reduced proliferation, promoted apoptosis, facilitated cell cycle progression from G₁ to S phase, and reduced cell migration and invasion of RLPS cells. Protein microarray analysis and western blotting showed that the Janus Kinase/Signal transducers and activators of transcription pathway was downregulated following TYMS knockdown. In conclusion, TYMS expression is upregulated in RLPS tissues, and downregulation of TYMS reduces RLPS progression.

Diaphragmatic liposarcoma with gall bladder invasion: CT and MRI findings

Primary liposarcoma originating from the diaphragm is an extremely rare case. Seventy-four-year-old male presented to emergency department with worsening right upper quadrant abdominal pain with dyspnea. Contrast-enhanced computed tomography of the abdomen demonstrated lobulated mass in right hemidiaphragm exhibiting mass effects to adjacent structures compressing gall bladder. Magnetic resonance imaging of the abdomen showed diaphragmatic mass with heterogeneous signal intensities with partial diffusion restriction. Surgical removal was performed and histology confirmed dedifferentiated liposarcoma arising from the diaphragm with gall bladder invasion.

Peutz-Jeghers syndrome with mesenteric fibromatosis: A case report and review of literature

BACKGROUND

Peutz-Jeghers syndrome (PJS) and mesenteric fibromatosis (MF) are rare diseases, and PJS accompanying MF has not been previously reported. Here, we report a case of a 36-year-old man with both PJS and MF, who underwent total colectomy and MF surgical excision without regular follow-up. Two years later, he sought treatment for recurrent acute abdominal pain. Emergency computed tomography showed multiple soft tissue masses in the abdominal and pelvic cavity, and adhesions in the small bowel and peritoneum. Partial intestinal resection and excision of the recurrent MF were performed to relieve the symptoms.

CASE SUMMARY

A 36-year-old male patient underwent total colectomy for PJS with MF. No regular reexamination was performed after the operation. Two years later, due to intestinal obstruction caused by MF enveloping part of the small intestine and peritoneum, the patient came to our hospital for treatment. Extensive recurrence was observed in the abdomen and pelvic cavity. The MF had invaded the small intestine and could not be relieved intraoperatively. Finally, partial bowel resection, proximal stoma, and intravenous nutrition were performed to maintain life.

CONCLUSION

Regular detection is the primary way to prevent deterioration from PJS. Although MF is a benign tumor, it has characteristics of invasive growth and ready recurrence. Therefore, close follow-up of both the history of MF and gastrointestinal surgery are advisable. Early detection and early treatment are the main means of improving patient prognosis.